TW201918409A

TW201918409A - Structural material capable of making the occurrence of fracture initiated at the vicinity of the welded part formed by welding difficult

Info

Publication number: TW201918409A
Application number: TW106137666A
Authority: TW
Inventors: 広瀬智史; 濵田幸一; 富士本博紀; 岡田徹
Original assignee: 日商新日鐵住金股份有限公司
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2019-05-16
Also published as: TWI658960B

Abstract

The present invention provides a structural material composed of a steel sheet having a tensile strength of 980 Mpa or more overlapped with another metal plate which are joined by welding, which can make the occurrence of fracture initiated at the vicinity of the welded part formed by welding difficult. The structural material comprises: a steel sheet having a tensile strength of 980 Mpa or more as the first member, a metal plate overlapped with the first plate part as the second member, a plurality of welded parts, and a plurality of heat-affected parts formed around each of the plurality of welded parts with Vickers hardness lower than that of the first member by 50 HV or more. A pair of end parts of the first member are provided between the adjacent heat-affected parts. The pair of end parts of the first member between the adjacent heat-affected parts are extended in a direction transverse to the line connecting the adjacent welded parts.

Description

Structural material

[0001] 本發明，是有關於包含重疊地被接合的板部的構造材。[0001] The present invention relates to a structural material including a plate portion that is joined in an overlapping manner.

[0002] 習知，是使用將複數板重疊地接合地構成的構造材。例如，日本特開平8-337183號公報(專利文獻1)的強度構件，是具有將2枚的薄板部從左右方向相面對地結合且形成了閉剖面的構成。結合用的凸緣是被延設在2枚的薄板部的各上下中。2枚的薄板部的凸緣是被對接且藉由點焊而被結合。　　[0003] 且在日本特開2006-142905號公報(專利文獻2)中，記載了能量吸收構件。此能量吸收構件，是具備：帽型材、及將帽型材的開放部閉塞的板狀的封閉托板。帽型材及封閉托板，是藉由點焊而彼此被接合。 [習知技術文獻] [專利文獻] 　　[0004] 　　[專利文獻1]日本特開平8-337183號公報　　[專利文獻2]日本特開2006-142905號公報[0002] It is known to use a structural material in which a plurality of plates are overlapped and joined. For example, the strength member of the Japanese Patent Publication No. 8-337183 (Patent Document 1) has a configuration in which two thin plate portions are joined to face each other in the left-right direction and have a closed cross section. The flange for bonding is extended in the upper and lower sides of the two thin plate portions. The flanges of the two thin plate portions are butted and joined by spot welding. An energy absorbing member is described in Japanese Laid-Open Patent Publication No. 2006-142905 (Patent Document 2). This energy absorbing member is provided with a cap profile and a plate-shaped closing pallet that closes the open portion of the cap profile. The cap profiles and the closure pallets are joined to each other by spot welding. [Patent Document 1] [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei No. Hei 8-337183 (Patent Document 2) JP-A-2006-142905

[本發明所欲解決的課題] 　　[0005] 在上述習知技術中，未考慮藉由點焊被重疊的板的焊接部的強度。被重疊的板，是由拉伸強度為980MPa以上的高強度的鋼板形成的情況，在焊接部的周圍，會發生藉由焊接時的熱而軟化的熱影響部。此熱影響部是成為構造材的弱點。例如汽車的B柱是和其他的汽車衝突而變形的情況，在B柱的長度方向會發生拉伸應力。此時，凸緣的熱影響部是藉由拉伸應力而斷裂。　　[0006] 在此，本案，是揭示具有將拉伸強度為980MPa以上的鋼板與其他的金屬板重疊藉由焊接被接合的構成的構造材，使以由焊接所形成的焊接部附近作為起點的斷裂不易發生的構成。 [用以解決課題的手段] 　　[0007] 本發明的實施例中的構造材，是具備：拉伸強度是980MPa以上的鋼板的第1構件、及與前述第1板部重疊的金屬板的第2構件、及將前述第1構件及前述第2構件藉由焊接被連接的複數焊接部、及形成於前述複數焊接部各周圍的前述第1構件且維氏硬度是比前述第1構件的維氏硬度低50HV以上的複數熱影響部、及在相鄰接的前述熱影響部之間朝將連結相鄰接的前述焊接部的線橫切的方向延伸的前述第1構件的一對的端部。 [發明的效果] 　　[0008] 依據本發明的實施例的話，對於將拉伸強度是980MPa以上的鋼板與其他的金屬板重疊藉由焊接被接合的構造材，可以難發生以焊接部附近作為起點的斷裂。[Problems to be Solved by the Invention] [0005] In the above-described conventional technique, the strength of the welded portion of the plate which is overlapped by spot welding is not considered. The superposed plate is formed of a high-strength steel sheet having a tensile strength of 980 MPa or more, and a heat-affected portion which is softened by heat during welding occurs around the welded portion. This heat-affected zone is a weakness of the structural material. For example, when the B-pillar of a car is deformed in conflict with other cars, tensile stress occurs in the longitudinal direction of the B-pillar. At this time, the heat-affected portion of the flange is broken by the tensile stress. [0006] In the present invention, a structural material having a structure in which a steel sheet having a tensile strength of 980 MPa or more and another metal plate are joined by welding is joined, and a vicinity of a welded portion formed by welding is used as a starting point. A structure in which fracture does not easily occur. [Means for Solving the Problem] The structural material according to the embodiment of the present invention includes a first member of a steel sheet having a tensile strength of 980 MPa or more and a metal plate overlapping the first plate portion. a member, a plurality of welded portions that are joined by welding the first member and the second member, and the first member formed around each of the plurality of welded portions, and having a Vickers hardness higher than a dimension of the first member a plurality of heat-affected portions having a hardness lower than 50 HV and a pair of ends of the first member extending in a direction transverse to a line connecting the adjacent welded portions between the adjacent heat-affected portions unit. [Effects of the Invention] According to the embodiment of the present invention, it is difficult to cause the steel sheet having a tensile strength of 980 MPa or more to be joined to another metal sheet by welding, and the vicinity of the welded portion can be used as a starting point. The break.

[0010] 將鋼板的第1構件、及金屬板的第2構件重疊接合的方法，多使用焊接。發明人等，是調查了由彼此被接合的第1構件及第2構件所構成的構造材的變形舉動。在構造材，朝與第1構件及第2構件的板面垂直的方向被施加力的話，構造材會變形彎曲。發現：將第1構件的材料的拉伸強度提高的情況，構造材若變形的話，將第1構件及第2構件藉由焊接被連接的焊接部附近容易斷裂。　　[0011] 發明人等，是對於此現象，如以下進行考察。在第1構件及第2構件是藉由焊接被接合的部分即焊接部中，在焊接時熱被施加。焊接部的周圍的部分，也會受到由焊接時的熱所產生的影響。焊接在拉伸強度是980MPa以上的鋼板的情況時，焊接部的周圍會藉由焊接時的熱而軟化。在拉伸強度是980MPa以上的鋼材中，為了實現較高的拉伸強度，而包含硬質相。焊接時的熱因為會使其硬質相變質，所以會發生軟化。具體而言，回火麻田散鐵會變質成鐵酸鹽。面內方向的拉伸應力變大的話，焊接部的周圍的藉由焊接時的熱而軟化的部分是成為起點使第1構件或是第2構件斷裂。　　[0012] 發明人等，是依據上述的考察，檢討了抑制發生於焊接部的周圍的軟化部因為面內方向的拉伸應力而斷裂用的構成。發明人等，是反覆各式各樣的解析及實驗的結果，想到了將拉伸強度980MPa以上的鋼板的焊接部的周圍的軟化的部分彼此之間切斷。即想到了，在拉伸強度980MPa以上的鋼板的焊接部的周圍的軟化的部分彼此之間設置一對的端部。由此發現了，在面內方向的拉伸應力增大時可以抑制焊接部的周圍的部分是成為起點斷裂。依據此了解，而想到了下述的實施例。　　[0013] (構成1) 　　本發明的實施例的構成1中的構造材，是具備：拉伸強度是980MPa以上的鋼板的第1構件、及與前述第1板部重疊的金屬板的第2構件、及將前述第1構件及前述第2構件藉由焊接被連接的複數焊接部、及形成於前述複數焊接部各周圍的前述第1構件且維氏硬度是比前述第1構件的維氏硬度低50HV以上的複數熱影響部、及在相鄰接的前述熱影響部之間且朝將連結相鄰接的前述焊接部的線橫切的方向延伸的前述第1構件的一對的端部。　　[0014] 在構成1中的構造材中，在拉伸強度是980MPa以上的第1構件的複數焊接部各周圍，形成維氏硬度是比第1構件的硬度低50HV以上的熱影響部。相鄰接的熱影響部之間是被切斷。即，第1構件的相鄰接的熱影響部之間設有第1構件的一對的端部。一對的端部，是朝將連結相鄰接的熱影響部的各內側的焊接部的線橫切的方向延伸。即，朝將連結相鄰接的焊接部的線橫切的方向延伸。藉由此構成，構造材是承受與第1構件的板面垂直的方向的力而變形的情況，可以將作用於熱影響部的第1構件的面內方向的拉伸應力緩和。因此，在構造材的變形時可以不易引起以熱影響部作為起點的斷裂。即，使拉伸強度是980MPa以上的鋼板與其他的金屬板重疊並藉由焊接被接合的構造材，可以難發生以焊接部附近作為起點的斷裂。　　[0015] (構成2) 　　在上述構成1的構造材中，前述一對的端部，是將連結前述相鄰接的焊接部的中心的線橫剖較佳。由此，更容易獲得將作用於熱影響部的拉伸應力緩和的效果。又，焊接部的中心，是從與第1構件的板面垂直的方向所見，在一方向將焊接部2等分的線分的中點。在此，第1構件的板面，是作為第1構件的面之中與第2構件接觸的面即與第2構件的接合面。　　[0016] (構成3) 　　對於上述構成2的構造材，前述一對的端部，是將前述相鄰接的熱影響部的內周緣之間的領域的端部橫剖較佳。由此，更容易獲得將作用於熱影響部的拉伸應力緩和的效果。　　[0017] (構成4) 　　對於上述構成2或3的其中任一的構造材，前述一對的端部，是將前述相鄰接的熱影響部之間的領域橫剖較佳。由此，更容易獲得將作用於熱影響部的拉伸應力緩和的效果。　　[0018] (構成5) 　　對於上述構成1～4的其中任一的構造材，前述一對的端部，是形成於前述第1構件的孔的緣較佳。將相鄰接的熱影響部之間的第1構件的端部，作為孔的緣的話，與切入形成的情況相比，容易確保第1構件的強度。　　[0019] (構成6) 　　對於上述構成1～5的其中任一的構造材，前述第2構件的拉伸強度，是未滿1180MPa，在前述相鄰接的焊接部之間的前述第2構件中沒有端部較佳。前述第2構件的拉伸強度，是未滿980MPa更佳。前述第2構件的拉伸強度，是未滿800MPa更佳。前述第2構件的拉伸強度，是未滿720MPa是進一步較佳。藉由將前述第2構件的拉伸強度如此地降低，與第2構件的硬度相比，可以抑制焊接部的周圍是藉由焊接的熱而軟化。藉由抑制第2構件的焊接部的周圍的軟化，不易引起由面內方向的拉伸應力的增大所產生的焊接部附近的斷裂。因此，第2構件，即使未作成將第2構件的一對的端部配置在相鄰接的熱影響部之間的構成，仍可以不易引起焊接部附近的斷裂。且，藉由在第2構件的相鄰接的焊接部之間不設置端部，就容易確保構造構件的強度。　　[0020] (構成7) 　　對於上述構成1～6的其中任一的構造材，前述第2構件的拉伸強度是980MPa以上的鋼板較佳。進一步最好是，第2構件的拉伸強度是1180MPa以上的鋼板較佳。如此的話可以提高構件的強度。但是，在該情況，有可能發生第2構件的焊接部附近也軟化的熱影響部。該對策，是藉由在相鄰接的焊接部之間設置第2構件的一對的端部，就可以難發生以焊接部附近作為起點的斷裂。　　[0021] (構成8) 　　對於上述構成1～6的其中任一的構造材，在前述複數焊接部的周圍的前述第2構件中，沒有維氏硬度是比前述第2構件的硬度低50HV以上的熱影響部較佳。在第2構件的焊接部的周圍沒有熱影響部的情況，不易引起由面內方向的拉伸應力的增大所產生的焊接部附近的斷裂。因此，第2構件，即使未作成將第2構件的一對的端部配置在相鄰接的熱影響部之間的構成，仍可以不易引起焊接部附近的斷裂。　　[0022] (構成9) 　　對於上述構成1～8的其中任一的構造材，前述焊接部的兩側中的前述一對的端部的前述焊接部側的一方彼此的間隔，是前述焊接部的徑的6倍以下較佳。換言之，前述複數焊接部，是包含：由點焊所形成的第1焊接部、與前述第1焊接部相鄰接的第2焊接部、及與前述第2焊接部相鄰接的第3焊接部也可以。從與前述第1構件的板面垂直的方向所見，從前述第2焊接部至位於前述第2焊接部及前述第1焊接部之間的前述第1構件的端部的最接近的位置為止的距離、及從前述第2焊接部至位於前述第2焊接部及前述第3焊接部之間的前述第1構件的端部的最接近的位置為止的距離的合計，是前述第1焊接部的直徑的6倍以下較佳。　　[0023] 藉由構成9，藉由與第1構件的板面垂直的方向的力而使構造材變形的情況時，可以減輕第1焊接部的負擔。且，可以抑制朝第1焊接部的變形集中。　　[0024] (構成10) 　　對於上述構成1～9的其中任一的構造材，將前述一對的端部彼此連結的端部的軌跡的曲率半徑，是10mm以下較佳。換言之，從與前述第1構件的板面垂直的方向所見，由前述相鄰接的熱影響部之間的前述第1構件的一對的端部所形成的第1構件的缺口或是孔的角部的曲率半徑，是10mm以下較佳。由此，可以抑制藉由與第1構件的板面垂直的方向的力使構造材變形的情況時的第1構件及第2構件中的變形集中。　　[0025] (構成11) 　　對於上述構成1～10的其中任一的構造材，前述第1構件是包含稜線部，前述一對的端部及與前述一對的端部連接的端部，是不將前述稜線部分斷較佳。即，形成於相鄰接的熱影響部之間的前述第1構件的一對的端部之間的第1構件的端部，是設於不會到達前述稜線部的位置較佳。第1構件的端部，是藉由形成不將稜線部分斷的構成，與第1構件的端部是將稜線部分斷的構成相比，可以提高構造構件的強度。　　[0026] 例如，前述第1構件或是第2構件的至少1個，是具有朝面外方向被彎曲的彎曲部也可以。此情況，彎曲部是成為稜線部。複數焊接部，是例如，被配置於稜線部的延伸的方向也可以。相鄰接的熱影響部之間的第1構件的一對的端部之間的端部，是不延伸至稜線部較佳。因為稜線被分斷的話，此構件就容易折曲。　　[0027] 上述構成1～11的其中任一的構造材，是藉由前述第1構件及第2構件形成閉剖面也可以。將所形成的閉剖面的處稱為閉剖面部。即，第1構件的板面的彼此分離的至少2處是與第2構件接觸也可以。此情況，與第1構件的第2構件接觸的2處之間的部分，是與第2構件分離。第1構件及第2構件被重疊的部分，是藉由焊接被接合。使第1構件及第2構件重疊地被接合的部分，是形成被配置於閉剖面部的內側或是外側的凸緣。凸緣，是朝閉剖面部的軸方向延伸。例如，第1構件是帽型構件，第2構件是封閉托板也可以。因為將第1構件作成帽型材的話，構件的強度可由稜線被確保。板面是容易面外變形，對於此，稜線不易變形。將該稜線由高強度材形成的話成為強度高的構件。　　[0028] 上述構成1～11的其中任一的構造材，是包含藉由至少1枚的板形成閉剖面的閉剖面部也可以。形成閉剖面的板，是包含前述第1構件及前述第2構件。此情況，第1構件及第2構件，皆形成閉剖面部的板的一部分。第1構件及第2構件，是彼此重疊並藉由焊接被接合。被重疊的第1構件及第2構件，是形成被配置於前述閉剖面部的內側或是外側的凸緣也可以。或是被重疊的第1構件及第2構件，是形成前述閉剖面部的一部分也可以。　　[0029] 對於上述構成1～11的其中任一的構造材，第1構件的金屬組織，是將回火麻田散鐵作為主相。鋼板的拉伸強度為了成為980MPa以上，有必要將回火麻田散鐵作為主相。即，第1構件中的回火麻田散鐵的面積率，是25%以上。又，第1構件中的回火麻田散鐵的面積率，是100%也可以。第2構件的金屬組織，是將鐵酸鹽作為主相較佳。即，第2構件中的鐵酸鹽相的面積率，是30%以上也可以。第2構件中的鐵酸鹽的面積率的上限是95%也可以。或是第2構件的回火麻田散鐵的面積率是70%以下也可以。藉由如此，可以迴避在焊接部的周圍的第2構件軟化的熱影響部出現。　　[0030] [實施例] 　　第1A圖，是顯示本實施例中的構造材10的立體圖。第1B圖，是將第1A圖所示的構造材10從與長度方向垂直的方向(z方向)所見的俯視圖。第1C圖，是第1B圖中的圓B部分的放大圖。第1D圖，是第1B圖及第1C圖中的A-A線的剖面圖。　　[0031] 構造材10，是將鋼板及金屬板(即使不是鋼板也可以)組合而構成。這些之中的1個是帽型構件1，其他的1個是封閉托板2。帽型構件1，是具有帽型的剖面。帽型構件1的凸緣、及封閉托板2的一部分是彼此重疊地被接合。帽型構件1，是第1構件的一例。封閉托板2，是第2構件的一例。　　[0032] 如第1A圖所示，帽型構件1，是具有：頂面部1a、及側壁1b、及凸緣1c。側壁1b，是從頂面部1a的兩端延伸，彼此相面對。凸緣1c，是各別連接在側壁1b，從側壁1b的頂面部1a側的一方端部相反側的另一方端部朝彼此遠離的方向延伸。即，2個凸緣1c，是從側壁1b的另一方端部，在側壁1b的相面對方向朝外側延伸。封閉托板2，是被接合在凸緣1c地設置。　　[0033] 頂面部1a及側壁1b的交界部分(肩部)，是成為帽型構件1的彎曲部(第1彎曲部1ab)。第1彎曲部1ab，是形成朝構造材10的長度方向(x方向)延伸的稜線。各側壁1b及各凸緣1c的交界部分，是成為帽型構件1的第2彎曲部1bc。第2彎曲部1bc，也形成朝x方向延伸的稜線。　　[0034] 凸緣1c、及封閉托板2，是重疊地被接合。在本例中，藉由點焊，而使凸緣1c及封閉托板2被接合。在第1A圖～第1C圖中，將藉由焊接而使凸緣1c及封閉托板2被接合的焊接部3的位置由虛線顯示。如第1D圖所示，凸緣1c及封閉托板2是藉由焊接一體化的處，是成為焊接部3。　　[0035] 帽型構件1，是由拉伸強度是980MPa以上的鋼板所形成。帽型構件1，是將金屬板成形而成者。封閉托板2，是由金屬所形成。封閉托板2的拉伸強度，無特別限定。　　[0036] 如第1D圖所示，凸緣1c及封閉托板2，是在2處被重疊。彼此重疊的凸緣1c及封閉托板2，是形成結合板部101。結合板部101，是彼此重疊地接合的板部的一例。即，與封閉托板2的凸緣1c接觸的部分2b、及凸緣1c，是成為重疊並藉由焊接部3被接合的結合板部101。結合板部101，是成為構造材10的凸緣。在第1D圖中結合板部101有2處。這些的結合板部101之間，具有帽型構件1及封閉托板2是彼此分離地延伸的閉剖面部102。即，藉由帽型構件1及封閉托板2，形成有閉剖面部102。閉剖面部102，是由：帽型構件1的側壁1b及頂面部1a、及封閉托板2的與凸緣1c接觸的部分2b之間的部分2a所構成。即，閉剖面部102，是由將中空部包圍的板部所形成。　　[0037] 如此，構造材10，是具有：由將中空部包圍的板部所形成的閉剖面部102、及與閉剖面部102連續地配置於閉剖面部102的外側的凸緣(結合板部101)。閉剖面部102，是形成管。凸緣1c及封閉托板2接合的部分(即結合板部101)，是成為從管至突出的凸緣。　　[0038] 在第1A圖～第1D圖所示的例中，形成有閉剖面部102的管的軸方向，是x方向。結合板部101，即構造材10的凸緣，是朝x方向延伸地形成。在此例中，由閉剖面部102所形成的管的延伸方向(長度方向)、及構造材10的凸緣的延伸方向，是相同。又，構造材10的凸緣的延伸方向，是不一定必要，與由閉剖面部102所形成的管的延伸方向是不相同也可以。例如，將具備在長度方向高度變化的側壁1b的帽型材彼此組合也可以。　　[0039] 如第1C圖所示，凸緣1c及封閉托板2，是藉由複數焊接部3即複數點焊而被接合。在凸緣1c中的複數焊接部3的各周圍中，具有熱影響部5。熱影響部5，是藉由焊接部3的焊接時的熱而軟化的部分。熱影響部5，是比周圍更軟。維氏硬度，是將帽型構件1即比母材低50HV以上的部分作為熱影響部5。即，熱影響部5的維氏硬度，是比熱影響部5的周圍的部分的維氏硬度低50HV以上。　　[0040] 在封閉托板2中，在複數焊接部3的各周圍，具有熱影響部也可以，沒有也可以。但是，在封閉托板2具有拉伸強度下降的熱影響部的情況，封閉托板2的熱影響部之間也設置封閉托板的一對的端部。又，在第1B圖中，省略熱影響部的圖示。　　[0041] 如第1C圖所示，從與凸緣1c的與封閉托板2接觸的面垂直的方向(z方向)所見，在複數焊接部3之中各別形成在相鄰接的焊接部3的周圍的相鄰接的熱影響部5之間，設有凸緣1c的一對的端部4。相鄰接的熱影響部5之間的凸緣1c的一對的端部4，是朝將連結相鄰接的焊接部3的線橫切的方向延伸。　　[0042] 在第1C圖所示的例中，藉由相鄰接的熱影響部5之間的凸緣1c的一對的端部4，而在相鄰接的熱影響部5之間形成空隙。又，一對的端部4，是彼此接觸也可以。藉由相鄰接的熱影響部5之間的一對的端部4，而在相鄰接的熱影響部5之間形成不連續部。且，在封閉托板2，若具有拉伸強度下降的熱影響部5的情況，是在相鄰接的熱影響部5之間，配置一對的封閉托板2的端部。此情況，凸緣1c的相鄰接的熱影響部5之間的一對的端部、及封閉托板2的該相鄰接的焊接部之間的一對的端部，是從z方向所見被配置於一部分被重疊的位置也可以，被配置於彼此不會重疊的位置也可以。　　[0043] 焊接部3，是在x方向即第1彎曲部1ab及第2彎曲部1bc的稜線的延伸的方向並列地配置。在相鄰接的熱影響部5之間，凸緣1c，是藉由形成一對的端部4的不連續部而被分斷。　　[0044] 相鄰接的熱影響部5之間的一對的端部4，是阻礙施加於凸緣1c的力，在相鄰接的熱影響部5之間被傳達。例如，構造材10是承受外力而變形時，將凸緣1c變形的力是作動在某1個焊接部3及其周圍的熱影響部5。在1個熱影響部5及與其相鄰的熱影響部5之間具有一對的凸緣1c的端部4即不連續部。因為此不連續部，所以施加於1個熱影響部5的力，就不易朝相鄰的熱影響部5傳達。因此，相鄰接的熱影響部5可以彼此不被拘束地變形。其結果，施加於各熱影響部5的負荷是減少，熱影響部5是難斷裂。　　[0045] 如第1D圖所示，帽型構件1的第1彎曲部1ab及第2彎曲部1bc是成為圓弧彎曲的形狀，第1彎曲部1ab及第2彎曲部1bc的表面是包含曲面。即，第1彎曲部1ab及第2彎曲部1bc，是形成R(彎曲部)。在第1C圖及第1D圖中，將第1彎曲部1ab的R(彎曲部)的頂面部1a側的端作為R交界(R終止部)1e，將第2彎曲部1bc的R(彎曲部)的凸緣1c側的端部作為R交界(R終止部)1f。第1彎曲部1ab的稜線，是朝與R交界1e相同方向(x方向)延伸。第2彎曲部1bc的稜線，是朝與R交界1f相同方向(x方向)延伸。R交界是指彎曲部及與彎曲部相鄰接的面的交界。面的方向從相鄰接的面朝向彎曲部變化的處是視為R交界。　　[0046] 如第1C圖所示，從z方向(與接合面垂直的方向)所見的話，相鄰接的熱影響部5之間的一對的凸緣1c的端部4，是成為從凸緣1c的端部朝向內側(側壁1b)進入的缺口(開縫)的一部分。凸緣1c的缺口，是不延伸至側壁1b。更詳細的話，將相鄰接的熱影響部5之間的一對的凸緣1c的端部4之間連接的端部，是不延伸至凸緣1c及側壁1b的境界的第2彎曲部1bc(也參照第1D圖)。換言之，將相鄰接的熱影響部5之間的一對的凸緣1c的端部4之間連接的端部，是不延伸至形成於閉剖面部102及構造材10的凸緣之間的稜線。具體例，相鄰接的熱影響部5之間的一對的凸緣1c的端部4及將一對的端部4之間連接的凸緣1c的端部，是被配置於比第2彎曲部1bc的凸緣1c側的R交界1f更靠凸緣1c。即，從z方向(與接合面垂直的方向)所見，將相鄰接的熱影響部5之間的一對的凸緣1c的端部4之間連接的端部，是設於不與第2彎曲部1bc交叉的位置。其理由，是為了避免構件是容易在稜線被分斷處被折曲。將封閉托板2的相鄰接的焊接部3之間的一對的端部之間連接的端部，是從z方向所見，與第2彎曲部1bc交叉也可以，不交叉也可以。　　[0047] ＜熱影響部的例＞　　第2圖，是顯示焊接部3及熱影響部5的剖面構造及硬度分布的例的圖。第2圖的上部，是包含焊接部3及熱影響部5的部分的剖面圖。第2圖的下部，是顯示剖面圖中的線S中的維氏硬度的分布的圖表。在第2圖中，第1構件及第2構件是相同材質。焊接部3是在焊接時被加熱至熔融為止之後，被冷卻。因為焊接部3是藉由電極被拔熱，所以冷卻速度是非常地快。其結果，焊接部3被硬化。被硬化的結果，焊接部3及與焊接部3相鄰接的熱影響部是成為與第1構件同等的硬度。在從焊接部3被分離的周圍，具有藉由焊接時的熱使第1構件的被強化的組織變質而軟化的熱影響部。此軟化的熱影響部是冷卻速度慢的部分。將第2圖所示的焊接部3的周圍的軟化的部分特別稱為熱影響部5。在此，將從焊接部3遠離距離SD=10mm以上處的第1構件1的硬度視為第1構件的硬度。第2構件也同樣。第1構件的熱影響部5，是維氏硬度比第1構件的硬度低50HV以上的部分。在第1構件中從焊接部3遠離距離SD以上處的硬度，是成為第1構件的硬度。距離SD是依據第1構件的材質和板厚而變化。第1構件，是汽車用途的板厚1～2mm程度的鋼板的情況，視為SD=10mm。在第2構件若熱影響部出現的情況也同樣。即，第2構件的熱影響部，是維氏硬度比第2構件的硬度低50HV以上的部分。在第2構件從焊接部3遠離距離SD以上處的硬度，是成為第2構件的硬度。　　[0048] ＜一對的端部的配置例＞　　第3圖，是顯示凸緣1c中的相鄰接的熱影響部5之間的一對的凸緣1c的端部4的配置例的圖。第3圖，是從與凸緣1c的與封閉托板2接觸的面垂直的方向(z方向)所見的圖。如第3圖所示，在本實施例中，從z方向所見，在相鄰接的熱影響部51、52之間，朝將連結相鄰接的焊接部31、32的中心C1、C2之間的線LC1橫切的方向延伸的凸緣1c的端部4是被配置2個。　　[0049] 在此，相鄰接的熱影響部之間，是指熱影響部51的外周緣51g及與其相鄰的熱影響部52的外周緣52g之間的領域。在第3圖的例中，被熱影響部51的外周緣51g、52g、線LG1、及線LG2包圍的領域，是成為相鄰接的熱影響部之間。　　[0050] 將連結相鄰接的焊接部31、32的中心C1、C2之間的線LC1橫切的方向，是指對於此線LC1具有角度的方向。不限於與線LC1垂直的方向。且，一對的凸緣1c的端部4，是與將相鄰接的焊接部的中心之間連結的線LC1交叉、不交叉也可以。　　[0051] 如第3圖所示，相鄰接的熱影響部51、52之間的凸緣1c一對的端部4，是從z方向所見，將連結相鄰接的焊接部31、32的中心C1、C2的線LC1橫剖較佳。線LC1的方向中的熱影響部51、52的寬度，是在線LC1及熱影響部51、52重疊的部分最短。即，負荷最容易集中在線LC1上的熱影響部51、52。因此，藉由將相鄰接的焊接部31、32的中心C1、C2連結的線LC1、及凸緣1c的一對的端部4交叉，可以有效地抑制朝凸緣1c的變形時的熱影響部51、52的負荷。　　[0052] 且在第3圖所示的例中，熱影響部51、52之間的凸緣1c的一對的端部4，是將線LC1及線LN2橫切。線LN1及線LN2，是熱影響部51的內周緣51n及與其相鄰的熱影響部52的內周緣52n之間的領域的端部。這些的熱影響部51、52之間的凸緣1c的一對的端部4，是將線LC1、及這些的2條的線LN1、LN2之中至少1條橫切較佳。由此，可以有效地抑制朝凸緣1c的變形時的熱影響部51、52的負荷。　　[0053] 又，熱影響部51、52之間的一對的凸緣1c的端部4，是將連結焊接部31、32的中心C1、C2之間的線LC1橫切，不將2條的線LN1、LN2橫切的構成也可以。在第4圖所示的例中，熱影響部51、52之間的一對的凸緣1c的端部4，是將線LC1橫切，不將2條的線LN1、LN2橫切。一對的凸緣1c的端部4，是形成於凸緣1c的孔的緣的一部分。　　[0054] 且熱影響部51、52之間的一對的凸緣1c的端部4，是將連結焊接部31、32的中心C1、C2之間的線LC1橫切，進一步，將2條的線LN1、LN2橫切的構成也可以。在第5圖所示的例中，熱影響部51、52之間的一對的凸緣1c的端部4，是將線LC1橫切，進一步，也將2條的線LN1、LN2橫切。　　[0055] 在第5圖所示的例中，熱影響部51、52之間的一對的凸緣1c的端部4，是將2條的線LG1、LG2橫切。線LG1及線LG2，是熱影響部51的外周緣51g及與其相鄰的熱影響部52的外周緣52g之間的領域的端部。此情況，熱影響部51、52之間的一對的凸緣1c的端部4，是將相鄰接的熱影響部51、52之間的領域橫剖。由此，可以有效地抑制朝凸緣1c的變形時的熱影響部51、52的負荷。　　[0056] ＜第2構件的變形例＞　　第6圖，是顯示第2構件的一例也就是封閉托板2的變形例的圖。在封閉托板沒有拉伸強度下降的熱影響部的話，如第6圖所示，在相鄰接的焊接部31、32之間，封閉托板2的端部不交叉配置也可以。由此構成，也可以抑制凸緣1c變形時朝熱影響部51、52的負荷。封閉托板2的材料的拉伸強度，是未滿980MPa較佳。由此，焊接部3的周圍，是難因為焊接時的熱而軟化。如此，作為封閉托板2的材料，是選擇不會產生因為焊接的熱而軟化的部分的材料較佳。即，封閉托板2，是在焊接部3的周圍，沒有熱影響部較佳。沒有拉伸強度下降的熱影響部情況時，在封閉托板2的變形時不會引起以熱影響部為起點的斷裂。　　[0057] 如上述，在帽型構件1中，使用拉伸強度是980MPa以上的高強度材料。在此，在帽型構件1中，在凸緣1c的熱影響部51、52之間配置一對的凸緣1c的端部。對於此，在封閉托板2中，使用不會產生熱影響部的材料。在封閉托板2中，在焊接部3之間，不設置端部。由此，在帽型構件1使用高強度的材料的話，可以確保作為構造材10的強度。進一步，可以抑制藉由使用高強度材料而發生的軟化部所起因的斷裂。　　[0058] 第7圖，是顯示封閉托板2的拉伸強度未滿1180MPa的情況的焊接部附近的剖面、及維氏硬度的分布的例的圖。在第7圖中，第7圖的上部，是包含焊接部3的部分的剖面圖。第7圖的下部，是顯示在剖面圖中的線S及線S1的各維氏硬度的分布的圖表。在此圖表中，線T1，是顯示線S中的維氏硬度的分布，線T2，是顯示線S1中的維氏硬度的分布。　　[0059] 如第7圖所示，焊接部3的拉伸強度是比帽型構件1的硬度更低。這是因為帽型構件1及封閉托板2熔融混入焊接部3中，而成為硬度比帽型構件1低的組成。與帽型構件1的焊接部3相鄰接的受到熱的影響的領域，是與帽型構件1(母材)同等的硬度。從帽型構件1的焊接部3分離的領域的受到熱的影響的領域，是與帽型構件1相比硬度下降。帽型構件1的熱影響部5的硬度分布是與第2圖同樣。封閉托板2側的焊接部3的硬度是與帽型構件1的硬度同等。受到封閉托板2側的焊接部3的周圍的熱的影響的領域的硬度是隨著遠離焊接部3而下降。這是因為焊接後的冷卻速度是隨著遠離焊接部3而下降。接近焊接部3領域的冷卻速度較高，是因為由點焊的電極所產生的拔熱。在封閉托板2中沒有硬度比封閉托板2低50Hv以上的熱影響部。　　[0060] ＜第1構件及第2構件的變形例＞　　第8A圖，是顯示構造材的剖面形狀的變形例的剖面圖。第1D圖所示的構造材10a的剖面形狀，是對於封閉托板2的垂直2等分面(包含x軸的面)左右對稱的形狀。對於此，第8A圖所示的構造材10a，是對於封閉托板2的垂直2等分面左右非對稱。第8A圖所示的構造材10a的帽型構件1，是具有彼此形狀不同的2個側壁1b。2個側壁1b，其對於凸緣1c的角度、及z方向的高度HR、HL彼此不同。　　[0061] 在第8A圖所示的例中，2個側壁1b之中一方的側壁1b，是具有段差。且，2個側壁1b之中另一方的側壁1b，是成為呈圓弧彎曲的形狀。具體而言，從上述另一方的側壁1b的第1彎曲部1ab延伸的部分，形成R(圓弧)。　　[0062] 又，雖無圖示，頂面部1a、側壁1b、凸緣1c及封閉托板2的至少1個表面，不是平面而是曲面也可以。即，頂面部1a、側壁1b、凸緣1c及封閉托板2的至少1個，即使彎曲也可以。　　[0063] 在第8A圖中，省略熱影響部的圖示。以下，第9A圖～第14圖(除了第11B圖以外)，也省略熱影響部的圖示。　　[0064] 且在第8A圖所示的例中，封閉托板2，是具有朝遠離帽型構件1的方向突出的形狀。具體而言，封閉托板2，是包含：與帽型構件1的凸緣1c重疊的部分2b、及這些部分2b之間的部分2a。此部分2a，是成為朝遠離帽型構件1的方向突出的形狀。在此例中，封閉托板2的剖面形狀是成為帽型。由此，構成雙帽型形狀的構造材。在第8A圖所示的構成中，將帽型構件1作為第1構件，將封閉托板2作為第2構件也可以，或是將帽型構件1作為第2構件，將封閉托板2作為第1構件也可以。　　[0065] 第8B圖，是顯示構造材的剖面形狀的其他的變形例的剖面圖。在第8B圖所示的例中，可取代具備2個凸緣的帽型構件，而使用包含1個凸緣的溝型構件。第8B圖所示的構造材10b，是具有：溝型的溝型構件13、及封閉托板2、及將溝型構件13及封閉托板2接合的焊接部3r、3h。溝型構件13，是具備：頂面部1a、及從頂面部1a的兩端延伸的第1側壁1br及第2側壁1bh。第1側壁1br及第2側壁1bh，是彼此相面對。　　[0066] 凸緣1c是從第1側壁1b的頂面部1a的相反側的端部朝外側延伸。在第1側壁1br及凸緣1c的交界具有彎曲部1bcr。凸緣1c，是與封閉托板2重疊並藉由焊接部3r被接合。在包含第2側壁1bh的頂面部1a的相反側的端部的部分1bhd中，封閉托板2是被重疊。部分1bhd及封閉托板2，是藉由焊接部3h被接合。封閉托板2，是在與第2側壁1bh重疊的部分2bh的內側的端部具有彎曲部2abh。　　[0067] 又，溝型構件13，是不含凸緣也可以。在第8B圖所示的構成中，溝型構件13是第1構件的一例，封閉托板2是第2構件的一例。構造材10b，是包含：閉剖面部102、及被配置於閉剖面部102的外側的凸緣101r、101h。在凸緣101r、101h，形成有焊接部3r、3h。在焊接部3r、3h的周圍的溝型構件13具有熱影響部(圖示略)。　　[0068] 又，如第8C圖所示，形成有焊接部3的凸緣101，是被配置於閉剖面部102的內側也可以。在第8C圖所示的構造材10c中，凸緣101，是將閉剖面部102的一部分構成。構造材10c，是具備溝型構件13及封閉托板2。溝型構件13，是具備：頂面部1a、及從頂面部1a的兩端彼此相面對地延伸的側壁1b、及從側壁1b的頂面部1a的相反側彼此接近地延伸的凸緣1c。凸緣1c，是與封閉托板2重疊。在第8C圖所示的構成中，帽型構件1是第1構件的一例，封閉托板2是第2構件的一例。　　[0069] 第9圖，是顯示將3個板接合而成的構造材的例的剖面圖。第8圖所示的構造材10d，是對於第1D圖所示的構造材10，在將封閉托板2挾持地設於帽型構件1的相反側，更設置另一個帽型構件11。帽型構件11，是與帽型構件1同樣，具有頂面部11a、側壁11b、及凸緣11c。帽型構件1的凸緣1c、封閉托板2及帽型構件11的凸緣11c的3枚被重疊並藉由焊接部3而被接合。如此，構成構造材的板的枚數不限於2枚。且，重疊地被接合的板部的數量也不限於2枚。構造材，即使具有3枚以上的板重疊並藉由焊接部被接合的構成也可以。在第9圖所示的構成中，將帽型構件1、11的至少一方作為第1構件，將封閉托板2作為第2構件也可以。　　[0070] 第10圖，是變形例的構造材的剖面圖。第10圖所示的構造材10e，是具備：具有3個彎曲部12bb、12bc的第1板12、及不具有彎曲部的平板也就是第2板22。構造材10e，是具備：閉剖面部102、及朝閉剖面部102的外側突出的結合板部101。在結合板部101中，第1板12及第2板22被重疊，並藉由焊接而被結合。在第10圖所示的構成中，將第1板12作為第1構件，將第2板22作為第2構件也可以，或是將第1板12作為第2構件，將第2板22作為第1構件也可以。如此，構成閉剖面部的板，不限於只有如第1A圖～第1D圖所示的具有頂面部1a者。可以使用具有其他的彎曲部的板來構成閉剖面部。　　[0071] ＜構造材的變形例＞　　第11A圖，是變形例的構造材的剖面圖。第11B圖，是將第11A圖所示的構造材從z方向所見的俯視圖。第11A圖及第11B圖所示的構造材10f，是不具有閉剖面的構造。構造材10f，是具有：具有彎曲部13bc的第1板13、及不具有彎曲部第2板23。第1板13及第2板23，是彼此重疊，由焊接部3所構成。第1板13的拉伸強度，是980MPa以上。　　[0072] 第1板13，是包含第1結合板部13c及第1分離板部13b。第1結合板部13c，是與第2板23重疊地被接合。第1分離板部13b，是從第1結合板部13c的端部，對於第1板13及第2板23的接合面朝具有規定的角度(在本例中為大致直角)的面的方向延伸。第1結合板部13c及第1分離板部13b的境界，是成為第1板13的彎曲部13bc。　　[0073] 第1結合板部13c及第2板23，是彼此接觸，藉由焊接部3而被接合。焊接部3，是使第1板13的一部分及第2板23的一部分藉由焊接而一體化的部分即焊接部。如第11B圖所示，在第1結合板部13c及第2板23，設有複數焊接部3(點焊部)。在第1結合板部13c的複數焊接部3的各周圍中，具有熱影響部5。在相鄰接的熱影響部5之間，配置有第1結合板部13c的一對的端部4。第1結合板部13c的一對的端部4，是在相鄰接的熱影響部5之間形成不連續部。　　[0074] 複數焊接部3及熱影響部5，是在彎曲部13bc的稜線延伸的方向(x方向)並列地配置。第1結合板部13c的一對的端部4，是從第1結合板部13c的彎曲部13bc的相反側的端部朝向彎曲部13bc進入的開縫(缺口)的一部分。開縫，是不延伸至彎曲部13bc。具體而言，在第1結合板部13c及第1分離板部13b之間的彎曲的部分、及從z方向所見不會重疊的領域，形成開縫。即，將相鄰接的熱影響部之間的第1結合板部13c的一對的端部4之間連接的端部，是不與彎曲部13bc的R的第1結合板部13c側的端部13f交叉地配置。　　[0075] 如此，構造材，是不具有閉剖面構造也可以。且，構造材，是由不具有彎曲部的板所形成也可以。例如，在第11A圖所示的構成中，將第1板13，置換成不具有彎曲部的平板也可以。此情況，焊接部3及一對的端部4，是例如，與第11B圖同樣地配置也可以。在第11A圖及第11B圖所示的構成中，將第1板13作為第1構件，將第2板23作為第2構件也可以，或是將第1板13作為第2構件，將第2板23作為第1構件也可以。　　[0076] 第12圖，是變形例的構造材的剖面圖。第12圖所示的構造材10g，是將1枚的板14曲折形成管狀部(閉剖面部102)者。　　[0077] 構成構造材10g的1枚的板14，是作為彼此重疊地被接合的板部，包含第1板部14a及第2板部14e。第1板部14a及第2板部14e，是包含1枚的板14的端部的部分。彼此重疊的第1板部14a及第2板部14e，是與閉剖面部102連續，形成被配置於閉剖面部102的外側的凸緣101。即，在第12圖所示的例中，藉由1枚的板14，而形成閉剖面部102及凸緣101。　　[0078] 第1板部14a及第2板部14e，是藉由焊接部3而被接合。在第12圖中雖無圖示，焊接部3，是被複數設置。在第1板部14a及第2板部14e的焊接部3的周圍形成有熱影響部。第1板部14a的相鄰接的熱影響部之間，是設有第1板部14a的一對的端部。第2板部14e的相鄰接的熱影響部之間，是設有第2板部14e的一對的端部。在第1板部14a及第2板部14e中，焊接部3、熱影響部、及一對的端部的構成，是例如，可以與上述第1B圖、第1C圖、第2圖～第6圖中的第1構件的構成同樣。　　[0079] 板14，是在第1板部14a及第2板部14e之間，具有複數彎曲部14ab、14bc、14cd、14de。由這些的彎曲部14ab、14bc、14cd、14de所形成的稜線，是朝x方向延伸。雖無圖示，x方向，是構造材10g的長度方向也可以。此情況，構造材10g，是具有朝x方向延伸的管狀部。且，複數焊接部3，是被配置於彎曲部14ab、14bc、14cd、14de的稜線的延伸的方向。將形成於第1板部14a的相鄰接的熱影響部之間的一對的端部之間連接的端部，是不延伸至彎曲部14ab地形成。　　[0080] 又，構造材的閉剖面的形狀，不限定於四角形，包含其他的多角形或是曲線的形狀也可以。且，在如第12圖所示的例中，彼此重疊的板部也就是凸緣101，是被配置於閉剖面部102的外側。其他，如第13圖及第14圖所示，彼此重疊的板部，是形成於閉剖面部102內也可以。　　[0081] 在第13圖所示的構造材10h中，閉剖面部102，是包含重疊的板部14a、14e。彼此重疊的板部14a、14e，是藉由焊接部3而被接合。在第13圖中雖無圖示，焊接部3，是在x方向複數並列地配置。在複數焊接部3的板部14a、14e各周圍中，具有熱影響部。在板部14a及14e中，相鄰接的熱影響部之間配置有一對的端部。一對的端部的構成，是例如，可以與上述第1B圖、第1C圖、第2圖～第6圖同樣。將板部14a及板部14e的一對的端部之間連接的端部，是不延伸至板14的彎曲部14ab、14de地形成。　　[0082] 且由1枚的板14所形成的閉剖面部的閉剖面形狀，不限於四角形。例如，可以將具有多角形、圓形、橢圓形等其他的任意的形狀的閉剖面的閉剖面部由1枚的板14形成。第14圖，是顯示將具有圓形的閉剖面的閉剖面部102由1枚的板14形成的情況的構成例的圖。　　[0083] ＜對於焊接部＞　　又，形成焊接部用的焊接，不限於點焊。例如，藉由由雷射所產生的焊接或是電弧焊接，而形成焊接部也可以。電弧焊接、及由雷射所產生的焊接的其中任一的情況，當第1構件的拉伸強度是980MPa以上的情況時，在焊接部的周圍可產生熱影響部。此情況，與上述實施例同樣，在第1構件的相鄰接的熱影響部之間，配置第1構件的一對的端部較佳。由此，可以抑制以熱影響部作為起點的斷裂。　　[0084] 第15圖，是顯示由電弧焊接所產生的焊接部的例的圖。在第15圖所示的例中，在由電弧焊接所產生的焊接部31、32的周圍具有熱影響部51、52。在相鄰接的熱影響部51、52之間，配置有凸緣1c(第1構件)的一對的端部4。將由電弧焊接所產生的焊接部的長度方向作為長度方向LB，將與長度方向垂直的方向作為寬度方向LW。在長度方向中以將焊接部31、32進行2等分的線的中點，作為焊接部31、32的中心C1、C2。在第15圖所示的例中，將連結焊接部31、32的中心的線橫切地配置一對的端部4。將一對的端部4連接的端部4a，是不將R交界1f(第1構件的稜線部)分斷。　　[0085] ＜其他的變形例＞　　藉由焊接部被接合的鋼板的接合面即使彎曲也可以。構造材，是例如，朝與鋼板(或是板部)的接合面垂直的方向，或是朝與接合面平行的方向(面內方向)彎曲也可以。構造材，是由包含彎曲部的板所形成的情況，由彎曲部所形成的稜線是直線狀也可以，彎曲也可以。　　[0086] 複數焊接部，是在彎曲部的稜線的延伸的方向並列地配置的形態的其中一例，複數焊接部的至少焊接部，也有可能朝與稜線垂直的方向偏離配置的情況。又，複數焊接部，是在與彎曲部的稜線的延伸的方向垂直的方向並列地配置也可以。　　[0087] [模擬結果] 　　發明人等，是使用具備帽型構件及封閉托板的構造材的模型進行模擬，解析了外加衝擊時的構造材的變形舉動。使用將構造材中的凸緣的端部的構成改變的複數模型進行了模擬。模擬，是進行對於帽型構件1朝z方向將按壓子衝突的情況。　　[0088] 第16圖，是顯示使用於模擬的模型的圖。第17圖，是將第16圖所示的模型中的構造構件從上方(z方向)所見的圖。第18圖，是顯示第17圖所示的A-A線的剖面的剖面圖。第19圖，是在第17圖所示的領域E的放大圖。　　[0089] 在第16圖所示的模型中，從具有帽型構件41及封閉托板42的構造材的上方使撞擊器17衝突。構造材，是載置在並列於帽型構件41的長度方向的台19。在上方，蓋18是被披覆在帽型構件41的台19之間的中央部。帽型構件41，是具有頂面部41a、側壁41b及凸緣41c。凸緣41c，是被重疊在封閉托板42，藉由點焊被接合。蓋18，是與頂面部41a接觸。撞擊器17，是朝z方向前進與蓋18衝突。　　[0090] 如第17圖所示，由點焊所形成的焊接部43，是在與凸緣41c及側壁41b之間的稜線41bc的延伸的方向(x方向)相同的方向複數並列。在複數焊接部43的各周圍中，具有熱影響部45。熱影響部45的強度，是與帽型構件的母材的強度相比較低地設定。　　[0091] 如第18圖所示，在被帽型構件41及封閉托板42包圍的空間的內側中，配置有與帽型構件41接觸的補強構件46。補強構件46，是在帽型構件41的側壁41b及頂面部41a藉由焊接而被接合。封閉托板42，是沿著帽型構件41的凸緣41c及側壁41b之間的彎曲部地彎曲。第17圖的帽型構件41及封閉托板42的金屬板的拉伸強度是1470MPa，板厚是1.4mm。補強構件46的金屬板的拉伸強度是1470MPa，板厚是2.0mm。　　[0092] 如第19圖所示，在凸緣41c設置缺口。即，相鄰接的熱影響部45之間，配置有凸緣41c的一對的端部44。端部44，是朝y方向延伸。相鄰接的熱影響部45之間的凸緣41c的一對的端部44，是缺口的一部分。焊接部43的直徑ND、焊接部43的中心之間的距離C、x方向中的焊接部43的兩側的凸緣41c的端部44之間的長度S、缺口的y方向的長度α即缺口的深度α、凸緣41c的y方向的長度F、及缺口的角部的曲率半徑R，是被包含於模擬的參數。曲率半徑R，是將一對的端部44彼此連結的端部的軌跡的曲率半徑。　　[0093] 第20A圖～第20C圖，是顯示將缺口的y方向的長度α變化的情況的撞擊器衝突時的模擬結果的圖表。這些的圖表，是顯示α=0、α=(1/4)F、α=(1/2)F、α=(3/4)F、α=(1/2)F+(ND+1)、α=F、α=(5/4)F的各情況的計算值。第20A圖，是顯示至撞擊器最大荷重行程為止的最大剪斷力。第20B圖，是顯示變形集中部的相當塑性變形。第20C圖，是顯示熱影響部的相當塑性變形。　　[0094] 從第20A圖所示的結果發現，缺口的y方向的長度α，是比焊接部43的中心及凸緣41c的端緣的y方向中的距離更大(α＞(1/2)F)的話，焊接部的負擔會減少。從第20B圖所示的結果發現，缺口的深度愈深，熱影響部的負擔愈減。尤其是，缺口的y方向的長度α，是在比焊接部43的中心及凸緣41c的端緣的y方向中的距離更大的情況(α＞(1/2)F)，熱影響部的負擔是大幅地減少。從第20C圖所示的結果發現，缺口深度愈深，朝凸緣的變形集中愈增加。　　[0095] 第21A圖～第21C圖，是顯示將x方向中的焊接部43的兩側的端部44之間的長度S變化的情況的撞擊器衝突時的模擬結果的圖表。這些的圖表，是顯示S=26.6 mm、及S=15.3mm的各情況的計算值。第21A圖，是顯示至撞擊器最大荷重行程為止的最大剪斷力。第21B圖，是顯示變形集中部的相當塑性變形。第21C圖，是顯示熱影響部的相當塑性變形。　　[0096] 從第21A圖所示的結果發現，長度S愈大，朝焊接部的負擔愈增加。從第21B圖所示的結果發現，長度S愈大，朝凸緣的變形集中愈增加。從第21C圖所示的結果發現，朝長度S的熱影響部的負擔的影響是幾乎沒有。　　[0097] 第22A圖～第22C圖，是顯示將缺口的角部的曲率半徑R變化的情況的撞擊器衝突時的模擬結果的圖表。這些的圖表，是顯示R=0、R=5mm、及R=10mm的各情況的計算值。第22A圖，是顯示至撞擊器最大荷重行程為止的最大剪斷力。第22B圖，是顯示變形集中部的相當塑性變形。第22C圖，是顯示熱影響部的相當塑性變形。　　[0098] 從第22A圖所示的結果發現，朝缺口的角部的曲率半徑R的焊接部的影響是幾乎沒有。從第22B圖所示的結果發現，缺口的角部的曲率半徑R愈大，朝凸緣的變形集中愈增加。從第22C圖所示的結果發現，朝缺口的角部的曲率半徑R的熱影響部的負擔的影響是幾乎沒有。　　[0099] 上述的構造材，是可以最佳使用在變形和破壞被假定的構造材。特別是適用於本發明變形和破壞被假定的構造材的話，因為焊接部不易斷裂，所以可以獲得不容易被破壞的構造材。變形和破壞被假定的構造材的例可舉例車輛用構造材。車輛用構造材，具體而言，可舉例前車架、後車架、側門檻、前柱、中心柱、交叉構件、側軌道、風道、保險桿加強件、其他各種加強件(補強構件)的汽車構造體的車架系零件。且，本發明也可以適用在側板、擋泥板、衝撞板、踏板、中心板的汽車構造體的板系零件。這些汽車構造體因為是在汽車衝突時會被變形、破壞，所以可發揮本發明的效果。　　[0100] 將本發明的構造材作為車輛用的構造材使用的情況，例如，構造材的焊接部並列的方向或是彎曲部延伸的方向，是沿著車輛的外形地配置構造材也可以。即，構造材的焊接部並列的方向或是彎曲部延伸的方向，是對於來自車輛的外部的衝擊大致垂直交叉地配置構造材也可以。由此，構造材，即使是承受到來自車輛外部的衝擊的情況時，焊接部也可以更難斷裂。如此，將上述的構造材作為車輛用構造材者、和包含上述的構造材的車輛，也被包含於本發明的實施例。　　[0101] 且在本發明的構造材中，相鄰接的焊接部的對數是複數也可以。即，第1構件的相鄰接的熱影響部的對數是複數也可以。此情況，在複數熱影響部的對數之中至少一部分中，第1構件的一對的端部是設於相鄰接的熱影響部之間。且，第2構件的材料，不限於鋼材。例如，第2構件的材料，可以是鋼、鋁等其他金屬。　　[0102] 以上，雖說明了本發明的一實施例，但是上述的實施例只是實施本發明用的例示。因此，本發明不限定於上述的實施例，在不脫離其宗旨的範圍內可將上述的實施例適宜變形地實施。[0010] the first member of the steel sheet, And a method of overlapping and joining the second members of the metal plate, Use more welding. Inventor, etc. The deformation behavior of the structural member composed of the first member and the second member joined to each other was examined. In the construction material, When a force is applied in a direction perpendicular to the plate faces of the first member and the second member, The structural material will deform and bend. Find: When the tensile strength of the material of the first member is increased, If the structural material is deformed, The vicinity of the welded portion to which the first member and the second member are joined by welding is easily broken. [0011] Inventors, etc. Is for this phenomenon, Examine as follows. In the welded portion where the first member and the second member are joined by welding, Heat is applied during welding. The part around the weld, It is also affected by the heat generated during welding. When welding a steel sheet having a tensile strength of 980 MPa or more, The periphery of the welded portion is softened by the heat during welding. In a steel having a tensile strength of 980 MPa or more, In order to achieve higher tensile strength, It contains a hard phase. The heat during welding will deteriorate its hard phase. So softening will occur. in particular, The tempered granulated iron will deteriorate into ferrite. If the tensile stress in the in-plane direction becomes large, The portion which is softened by the heat during welding around the welded portion is a starting point to break the first member or the second member. [0012] Inventors, etc. Based on the above investigation, The structure for suppressing the fracture of the softened portion occurring around the welded portion due to the tensile stress in the in-plane direction was examined. Inventor, etc. It is the result of a variety of analysis and experiments. It is thought that the softened portions around the welded portion of the steel sheet having a tensile strength of 980 MPa or more are cut off from each other. I thought about it, A pair of end portions are provided between the softened portions around the welded portion of the steel sheet having a tensile strength of 980 MPa or more. Discovered by this, When the tensile stress in the in-plane direction is increased, it is possible to suppress the portion around the welded portion from being broken at the starting point. Based on this understanding, The following embodiments are contemplated. (Configuration 1) The structural material in the configuration 1 of the embodiment of the present invention, Yes with: The first member of the steel sheet having a tensile strength of 980 MPa or more, And a second member of the metal plate overlapping the first plate portion, And a plurality of welded portions that are connected by the first member and the second member by welding, And the first member formed around each of the plurality of welded portions and having a Vickers hardness of 50 HV or more lower than a Vickers hardness of the first member, And a pair of end portions of the first member extending between the adjacent heat-affected portions and extending in a direction transverse to a line connecting the adjacent welded portions. [0014] In the structural material in the configuration 1, Around each of the plurality of welded portions of the first member having a tensile strength of 980 MPa or more, The Vickers hardness is a heat-affected zone which is 50 HV or more lower than the hardness of the first member. The adjacent heat affected portions are cut off. which is, A pair of end portions of the first member are provided between the adjacent heat-affected portions of the first member. The end of a pair, It extends in a direction transverse to the line connecting the welded portions on the inner sides of the adjacent heat-affected portions. which is, It extends in a direction transverse to the line connecting the adjacent welded portions. By this, The structural material is deformed by a force in a direction perpendicular to the plate surface of the first member, The tensile stress in the in-plane direction of the first member acting on the heat-affected zone can be alleviated. therefore, When the structural material is deformed, it is difficult to cause the fracture with the heat-affected portion as a starting point. which is, a structural material in which a steel sheet having a tensile strength of 980 MPa or more is overlapped with another metal plate and joined by welding, It is difficult to occur a fracture starting from the vicinity of the welded portion. [Configuration 2] In the structural material of the above configuration 1, The ends of the aforementioned pair, It is preferable that the line connecting the centers of the adjacent adjacent welded portions is transversely cross-sectional. thus, It is easier to obtain an effect of alleviating the tensile stress acting on the heat-affected zone. also, The center of the weld, It is seen from the direction perpendicular to the board surface of the first member, The midpoint of the line in which the welded portion 2 is equally divided in one direction. here, The surface of the first member, Among the surfaces of the first member, the surface that is in contact with the second member, that is, the joint surface with the second member. (Configuration 3) With respect to the structural material of the above configuration 2, The ends of the aforementioned pair, It is preferable to cross-sectionally cross the end of the field between the inner peripheral edges of the adjacent heat-affected portions. thus, It is easier to obtain an effect of alleviating the tensile stress acting on the heat-affected zone. (Configuration 4) With respect to the structural material of any of the above configurations 2 or 3, The ends of the aforementioned pair, It is preferable to cross-sectionally cross the field between the adjacent heat-affected portions. thus, It is easier to obtain an effect of alleviating the tensile stress acting on the heat-affected zone. (Configuration 5) The structural material of any of the above configurations 1 to 4, The ends of the aforementioned pair, It is preferable that the edge of the hole formed in the first member is formed. The end of the first member between the adjacent heat affected portions, As the edge of the hole, Compared with the case of cutting in, It is easy to ensure the strength of the first member. (Configuration 6) With respect to any of the structures 1 to 5 described above, The tensile strength of the aforementioned second member, Is less than 1180 MPa, It is preferable that the second member among the adjacent welded portions is not provided with an end portion. The tensile strength of the aforementioned second member, It is better than 980 MPa. The tensile strength of the aforementioned second member, It is better than 800 MPa. The tensile strength of the aforementioned second member, It is further preferable that it is less than 720 MPa. By reducing the tensile strength of the second member as described above, Compared with the hardness of the second member, It is possible to suppress the periphery of the welded portion from being softened by the heat of welding. By suppressing softening around the welded portion of the second member, It is difficult to cause breakage in the vicinity of the welded portion due to an increase in tensile stress in the in-plane direction. therefore, The second component, Even if the end portion of the pair of second members is not disposed between the adjacent heat-affected portions, It is still not easy to cause breakage near the welded portion. And, By not providing an end portion between adjacent welded portions of the second member, It is easy to ensure the strength of the structural member. (Configuration 7) With respect to any of the structures 1 to 6 described above, The steel sheet having a tensile strength of 980 MPa or more is preferable. Further preferably, The steel sheet having a tensile strength of the second member of 1180 MPa or more is preferable. This can increase the strength of the component. but, In this case, There is a possibility that a heat-affected portion which is softened in the vicinity of the welded portion of the second member may occur. The countermeasure, By providing a pair of end portions of the second member between adjacent welded portions, It is difficult to occur a fracture starting from the vicinity of the welded portion. (Configuration 8) With respect to any of the structures 1 to 6 described above, Among the aforementioned second members around the plurality of welded portions, It is preferable that the Vickers hardness is 50 HV or more lower than the hardness of the second member. In the case where there is no heat affected portion around the welded portion of the second member, It is difficult to cause breakage in the vicinity of the welded portion due to an increase in tensile stress in the in-plane direction. therefore, The second component, Even if the end portion of the pair of second members is not disposed between the adjacent heat-affected portions, It is still not easy to cause breakage near the welded portion. (Configuration 9) With respect to any of the structures 1 to 8 described above, a distance between one of the welded portion sides of the pair of end portions of the pair of welded portions, It is preferably 6 times or less the diameter of the welded portion. In other words, The aforementioned plurality of welded parts, Yes contains: The first welded portion formed by spot welding, a second welded portion adjacent to the first welded portion, And a third welded portion adjacent to the second welded portion. Seen from a direction perpendicular to the plane of the first member, a distance from the second welded portion to the closest position of the end portion of the first member between the second welded portion and the first welded portion, And a total of distances from the second welded portion to the closest position of the end portion of the first member between the second welded portion and the third welded portion, It is preferably 6 times or less the diameter of the first welded portion. [0023] By constructing 9, When the structural material is deformed by a force in a direction perpendicular to the plate surface of the first member, The burden on the first welded portion can be reduced. And, The concentration of deformation toward the first welded portion can be suppressed. (Configuration 10) With respect to any of the structures 1 to 9 described above, a radius of curvature of a locus of an end portion connecting the ends of the pair of the above, It is preferably 10mm or less. In other words, Seen from a direction perpendicular to the plane of the first member, a notch of the first member formed by the pair of end portions of the first member between the adjacent heat-affected portions or a radius of curvature of a corner portion of the hole, It is preferably 10mm or less. thus, It is possible to suppress deformation of the first member and the second member when the structural member is deformed by the force in the direction perpendicular to the plate surface of the first member. (Configuration 11) The structural material of any of the above configurations 1 to 10, The first member includes a ridge portion. An end portion of the pair and an end portion connected to the pair of end portions, It is not preferable to partially break the aforementioned ridge line. which is, An end portion of the first member formed between the pair of end portions of the first member between the adjacent heat-affected portions, It is preferable to provide a position that does not reach the ridge portion. The end of the first member, By forming a structure that does not partially break the ridge line, Compared with the configuration in which the end portion of the first member is broken by the ridge line portion, The strength of the structural member can be increased. [0026] For example, At least one of the first member or the second member, It is also possible to have a curved portion that is curved in the out-of-plane direction. In this case, The bent portion is a ridge portion. Multiple welds, Is for example, It may be arranged in the direction in which the ridge portion extends. An end between a pair of end portions of the first member between the adjacent heat-affected portions, It is preferable not to extend to the ridge portion. Because the ridge line is broken, This component is easily bent. [0027] The structural member according to any one of the above configurations 1 to 11, It is also possible to form a closed cross section by the first member and the second member. The portion of the closed section formed is referred to as a closed section. which is, At least two places in which the plate faces of the first member are separated from each other may be in contact with the second member. In this case, a portion between two places that is in contact with the second member of the first member, It is separated from the second member. a portion where the first member and the second member are overlapped, It is joined by welding. a portion in which the first member and the second member are joined to each other, The flange is disposed on the inner side or the outer side of the closed cross section. Flange, It extends in the axial direction of the closed section. E.g, The first member is a cap member, The second member may be a closed pallet. Because the first member is made into a cap profile, The strength of the member can be ensured by the ridge line. The board surface is easily deformed out of plane. For this, The ridge line is not easily deformed. When the ridge line is formed of a high-strength material, it becomes a member having high strength. [0028] The structural material of any of the above configurations 1 to 11, It is also possible to include a closed cross-sectional portion in which a closed cross section is formed by at least one plate. Forming a closed profile plate, The first member and the second member are included. In this case, The first member and the second member, Both form part of the plate of the closed section. The first member and the second member, They overlap each other and are joined by welding. The first member and the second member that are overlapped, It is also possible to form a flange that is disposed on the inner side or the outer side of the closed cross-sectional portion. Or the first member and the second member that are overlapped, It is also possible to form a part of the closed cross section. [0029] With respect to the structural material of any of the above configurations 1 to 11, The metal structure of the first member, It is to use the tempered Ma Tian loose iron as the main phase. The tensile strength of the steel sheet is 980 MPa or more. It is necessary to use the tempered Ma Tian loose iron as the main phase. which is, The area ratio of the tempered granules in the first member, It is more than 25%. also, The area ratio of the tempered granules in the first member, It is 100%. The metal structure of the second member, It is preferred to use ferrite as the main phase. which is, The area ratio of the ferrite phase in the second member, It is 30% or more. The upper limit of the area ratio of the ferrite in the second member may be 95%. Or the area ratio of the tempered granules of the second member is 70% or less. With this, It is possible to avoid the occurrence of the heat-affected portion of the softening of the second member around the welded portion. [Embodiment] FIG. 1A, It is a perspective view showing the structural material 10 in this embodiment. Figure 1B, It is a top view seen in the direction (z direction) perpendicular to the longitudinal direction of the structural material 10 shown by FIG. Figure 1C, It is an enlarged view of the portion of the circle B in Fig. 1B. Figure 1D, It is a cross-sectional view taken along line A-A in Fig. 1B and Fig. 1C. [0031] the structural material 10, It is composed of a steel plate and a metal plate (if it is not a steel plate). One of these is a cap member 1, The other one is the closing pallet 2. Cap member 1, It is a profile with a hat shape. The flange of the cap member 1, And a part of the closing pallet 2 is joined to each other overlappingly. Cap member 1, It is an example of the first member. Closing pallet 2, It is an example of the second member. [0032] As shown in FIG. 1A, Cap member 1, Is with: Top face 1a, And side wall 1b, And the flange 1c. Side wall 1b, It extends from both ends of the top surface portion 1a. Face each other. Flange 1c, Is connected to the side wall 1b, The other end portion on the side opposite to the one end portion on the side of the top surface portion 1a of the side wall 1b extends in a direction away from each other. which is, 2 flanges 1c, Is from the other end of the side wall 1b, The outer side faces of the side walls 1b extend outward. Closing pallet 2, It is provided to be joined to the flange 1c. [0033] a boundary portion (shoulder portion) of the top surface portion 1a and the side wall 1b, It is a curved part (first bending part 1ab) which becomes the hat-shaped member 1. First bending portion 1ab, A ridge line extending in the longitudinal direction (x direction) of the structural member 10 is formed. a boundary portion between each side wall 1b and each flange 1c, It is the second bending part 1bc which becomes the hat-shaped member 1. Second bending portion 1bc, A ridge line extending in the x direction is also formed. [0034] flange 1c, And closing the pallet 2, They are joined in overlapping. In this case, By spot welding, The flange 1c and the closing pallet 2 are joined. In pictures 1A to 1C, The position of the welded portion 3 to which the flange 1c and the closing plate 2 are joined by welding is indicated by a broken line. As shown in Figure 1D, The flange 1c and the closing bracket 2 are integrated by welding. It is the welding part 3. [0035] the cap member 1, It is formed of a steel sheet having a tensile strength of 980 MPa or more. Cap member 1, It is formed by forming a metal plate. Closing pallet 2, It is formed of metal. The tensile strength of the closure pallet 2, There is no special limit. [0036] As shown in FIG. 1D, Flange 1c and closing plate 2, It is overlapped at 2 places. a flange 1c overlapping each other and a closing pallet 2, The bonding plate portion 101 is formed. Combining the plate portion 101, It is an example of the board part which overlaps mutually mutually. which is, a portion 2b that is in contact with the flange 1c of the closure pallet 2, And the flange 1c, It is a bonding board part 101 which overlaps and is joined by the welding part 3. Combining the plate portion 101, It is the flange of the structural material 10. In the first DD, there are two places in the joint plate portion 101. Between these combined plate portions 101, The hat-shaped member 1 and the closing pallet 2 are closed cross-sectional portions 102 that extend apart from each other. which is, By the cap member 1 and the closing plate 2, A closed section 102 is formed. Closed section 102, By: The side wall 1b and the top surface portion 1a of the cap member 1 And a portion 2a between the portion 2b of the closure pallet 2 that is in contact with the flange 1c. which is, Closed section 102, It is formed by a plate portion that surrounds the hollow portion. [0037] Thus, Structural material 10, Is with: a closed cross-sectional portion 102 formed by a plate portion surrounding the hollow portion, And a flange (bonding plate portion 101) that is disposed on the outer side of the closed cross-sectional portion 102 continuously with the closed cross-sectional portion 102. Closed section 102, It is formed into a tube. a portion where the flange 1c and the closing pallet 2 are joined (ie, the joint plate portion 101), It is the flange from the tube to the protrusion. [0038] In the examples shown in FIGS. 1A to 1D, Forming the axial direction of the tube having the closed section 102, It is the x direction. Combining the plate portion 101, That is, the flange of the structural material 10, It is formed to extend in the x direction. In this case, The extending direction (length direction) of the tube formed by the closed section 102, And the direction in which the flange of the structural member 10 extends, It is the same. also, The direction in which the flange of the structural material 10 extends, Is not necessarily necessary, It may be different from the direction in which the tube formed by the closed section 102 extends. E.g, The cap profiles having the side walls 1b that vary in height in the longitudinal direction may be combined with each other. [0039] As shown in FIG. 1C, Flange 1c and closing plate 2, It is joined by a plurality of welded portions 3, that is, a plurality of spot welds. In each circumference of the plurality of welded portions 3 in the flange 1c, It has a heat affected portion 5. Heat affected part 5, It is a portion softened by the heat at the time of welding of the welded portion 3. Heat affected part 5, It is softer than the surrounding. Vickers hardness, The cap-shaped member 1 is a portion that is 50 HV or more lower than the base material as the heat-affected portion 5. which is, Vickers hardness of heat affected portion 5, It is 50 HV or less lower than the Vickers hardness of the part around the heat-affected zone 5. [0040] in the closure pallet 2, Around each of the plurality of welded portions 3, It is also possible to have a heat affected part, No, it can. but, In the case where the closing tray 2 has a heat-affected portion in which the tensile strength is lowered, A pair of end portions of the closing pallet are also provided between the heat-affected portions of the closing pallet 2. also, In Figure 1B, The illustration of the heat affected portion is omitted. [0041] As shown in FIG. 1C, Seen from the direction perpendicular to the face of the flange 1c that is in contact with the closing pallet 2 (z direction), Each of the plurality of welded portions 3 is formed between the adjacent heat-affected portions 5 around the adjacent welded portions 3, A pair of end portions 4 of the flange 1c are provided. a pair of end portions 4 of the flange 1c between the adjacent heat-affected portions 5, It extends in a direction transverse to the line connecting the adjacent welded portions 3. [0042] In the example shown in FIG. 1C, By a pair of end portions 4 of the flange 1c between the adjacent heat-affected portions 5, A gap is formed between the adjacent heat-affected portions 5. also, a pair of ends 4, It is also possible to contact each other. By a pair of end portions 4 between adjacent heat-affected portions 5, A discontinuity is formed between the adjacent heat-affected portions 5. And, In the closed pallet 2, If there is a heat affected portion 5 having a decreased tensile strength, Is between the adjacent heat affected portions 5, The ends of the pair of closed pallets 2 are arranged. In this case, a pair of ends between the adjacent heat-affected portions 5 of the flange 1c, And closing a pair of ends between the adjacent welded portions of the pallet 2, It is also possible to see that it is arranged in a position where the part is overlapped from the z direction. It is also possible to arrange them at positions that do not overlap each other. [0043] the welded portion 3, It is arranged in the x direction, that is, the direction in which the ridgelines of the first curved portion 1ab and the second curved portion 1bc extend. Between adjacent heat affected portions 5, Flange 1c, It is broken by forming a discontinuous portion of the pair of end portions 4. [0044] a pair of end portions 4 between adjacent heat-affected portions 5, Is the force that is applied to the flange 1c, It is communicated between adjacent heat affected portions 5. E.g, When the structural material 10 is deformed by an external force, The force that deforms the flange 1c is the heat-affected portion 5 that acts on one of the welded portions 3 and its surroundings. Between the one heat-affected zone 5 and the heat-affected zone 5 adjacent thereto, there is a pair of end portions 4 of the flange 1c, that is, discontinuous portions. Because of this discontinuity, Therefore, the force applied to one heat-affected portion 5, It is not easy to convey to the adjacent heat-affected zone 5. therefore, The adjacent heat-affected portions 5 can be deformed without being restrained from each other. the result, The load applied to each heat-affected zone 5 is reduced, The heat affected portion 5 is hard to break. [0045] As shown in FIG. 1D, The first curved portion 1ab and the second curved portion 1bc of the hat member 1 are curved in a circular arc shape. The surfaces of the first curved portion 1ab and the second curved portion 1bc include curved surfaces. which is, The first curved portion 1ab and the second curved portion 1bc, It is the formation of R (curved portion). In the 1Cth and 1Dth drawings, The end on the side of the top surface portion 1a of the R (curved portion) of the first curved portion 1ab is referred to as an R boundary (R terminating portion) 1e, The end portion on the flange 1c side of the R (curved portion) of the second bending portion 1bc is referred to as an R boundary (R terminating portion) 1f. The ridgeline of the first curved portion 1ab, It extends in the same direction (x direction) as the intersection 1e of R. The ridgeline of the second curved portion 1bc, It extends in the same direction (x direction) as the R boundary 1f. The R junction refers to the boundary between the curved portion and the surface adjacent to the curved portion. The direction in which the direction of the face changes from the adjacent face toward the curved portion is regarded as the R boundary. [0046] As shown in FIG. 1C, Seen from the z direction (the direction perpendicular to the joint), The end portion 4 of the pair of flanges 1c between the adjacent heat-affected portions 5, It is a part of the notch (slit) which enters from the edge part of the flange 1c toward the inner side (side wall 1b). The notch of the flange 1c, It does not extend to the side wall 1b. In more detail, An end portion connecting the end portions 4 of the pair of flanges 1c between the adjacent heat-affected portions 5, It is the second curved portion 1bc that does not extend to the boundary between the flange 1c and the side wall 1b (see also FIG. 1D). In other words, An end portion connecting the end portions 4 of the pair of flanges 1c between the adjacent heat-affected portions 5, It does not extend to the ridge line formed between the closed cross-section portion 102 and the flange of the structural member 10. Specific example, An end portion of the pair of flanges 1c between the adjacent heat-affected portions 5 and an end portion of the flange 1c connecting the pair of end portions 4, The flange 1c is disposed on the R boundary 1f on the side of the flange 1c of the second bending portion 1bc. which is, Seen from the z direction (the direction perpendicular to the joint surface), An end portion connecting the end portions 4 of the pair of flanges 1c between the adjacent heat-affected portions 5, It is provided at a position that does not intersect the second bending portion 1bc. The reason, It is to avoid that the member is easily bent at the point where the ridge line is broken. Ending the connection between the ends of the pair of adjacent welded portions 3 of the pallet 2, Is seen from the z direction, It is also possible to cross the second bending portion 1bc, It is also possible to not cross. [Example of Heat Affecting Section] Fig. 2, The figure shows an example of the cross-sectional structure and the hardness distribution of the welded part 3 and the heat-affected part 5. The upper part of Figure 2, It is a cross-sectional view of a part including the welded portion 3 and the heat-affected portion 5. The lower part of Figure 2, It is a graph showing the distribution of Vickers hardness in the line S in the cross-sectional view. In Figure 2, The first member and the second member are made of the same material. The welded portion 3 is heated until it is melted at the time of welding. It is cooled. Because the welded portion 3 is extracted by the electrode, So the cooling rate is very fast. the result, The welded portion 3 is hardened. Hardened result, The welded portion 3 and the heat-affected portion adjacent to the welded portion 3 have the same hardness as the first member. Around the separation from the welded portion 3, There is a heat-affected zone which is softened by the heat of welding to deteriorate the strengthened structure of the first member. This softened heat affected portion is a portion where the cooling rate is slow. The softened portion around the welded portion 3 shown in Fig. 2 is particularly referred to as a heat-affected portion 5. here, The hardness of the first member 1 from the welded portion 3 away from the distance SD = 10 mm or more is regarded as the hardness of the first member. The second member is also the same. The heat affected portion 5 of the first member, It is a portion in which the Vickers hardness is lower than the hardness of the first member by 50 HV or more. The hardness of the first member from the welded portion 3 away from the distance SD, It is the hardness of the first member. The distance SD varies depending on the material and thickness of the first member. The first component, In the case of a steel plate having a thickness of 1 to 2 mm for automotive use, Considered SD = 10mm. The same applies to the case where the second member appears in the heat-affected zone. which is, The heat affected part of the second member, It is a portion in which the Vickers hardness is lower than the hardness of the second member by 50 HV or more. The hardness of the second member from the welded portion 3 away from the distance SD, It is the hardness of the second member. <Example of Arrangement of Ends of a Pair> FIG. 3, It is a view showing an arrangement example of the end portions 4 of the pair of flanges 1c between the adjacent heat-affected portions 5 in the flange 1c. Figure 3, It is a view seen from the direction (z direction) perpendicular to the surface of the flange 1c which contacted the closing pallet 2. As shown in Figure 3, In this embodiment, Seen from the z direction, In the adjacent heat affected portion 51, Between 52, Connecting the adjacent welded portions 31, Center C1 of 32 The end portion 4 of the flange 1c extending in the direction in which the line LC1 between C2 extends is two. [0049] Here, Between adjacent heat affected parts, It means the area between the outer peripheral edge 51g of the heat-affected zone 51 and the outer peripheral edge 52g of the heat-affected zone 52 adjacent thereto. In the example in Figure 3, The outer periphery 51g of the heat affected portion 51, 52g, Line LG1 And the area surrounded by the line LG2, It is between the adjacent heat affected parts. [0050] joining the adjacent welded portions 31, Center C1 of 32 The direction of the line LC1 between C2 is transverse, It refers to the direction in which the line LC1 has an angle. It is not limited to the direction perpendicular to the line LC1. And, The end 4 of the pair of flanges 1c, It is a line LC1 that is connected to the center of the adjacent welded portion, It is also possible to not cross. [0051] As shown in FIG. 3, Adjacent heat affected portion 51, a pair of ends 4 of the flange 1c between 52, Is seen from the z direction, Connecting the adjacent welded portions 31, Center C1 of 32 The cross-section of the line LC1 of C2 is preferred. a heat-affecting portion 51 in the direction of the line LC1, 52 width, Is online LC1 and heat affected part 51, 52 overlapping parts are the shortest. which is, The load is most likely to concentrate on the heat affected part 51 on the line LC1, 52. therefore, By connecting the adjacent welded portions 31, Center C1 of 32 C2 connected line LC1 And a pair of end portions 4 of the flange 1c intersect, The heat-affecting portion 51 at the time of deformation toward the flange 1c can be effectively suppressed, 52 load. [0052] and in the example shown in FIG. 3, Heat affected part 51, a pair of end portions 4 of the flange 1c between 52, The line LC1 and the line LN2 are cross-cut. Line LN1 and line LN2, It is an end portion of the field between the inner peripheral edge 51n of the heat-affected portion 51 and the inner peripheral edge 52n of the heat-affected portion 52 adjacent thereto. These heat affected parts 51, a pair of end portions 4 of the flange 1c between 52, Is the line LC1 And these two lines LN1 It is preferable that at least one of LN2 is transversely cut. thus, The heat-affecting portion 51 at the time of deformation toward the flange 1c can be effectively suppressed, 52 load. [0053] Again, Heat affected part 51, The end 4 of the pair of flanges 1c between 52, Is to connect the welded portion 31, Center C1 of 32 The line LC1 between C2 is transversely cut, Do not put 2 lines LN1 The configuration of LN2 crosscutting is also possible. In the example shown in Figure 4, Heat affected part 51, The end 4 of the pair of flanges 1c between 52, Is to cross the line LC1, Do not put 2 lines LN1 LN2 cross cut. The end 4 of the pair of flanges 1c, It is a part of the edge of the hole formed in the flange 1c. [0054] and the heat affected portion 51, The end 4 of the pair of flanges 1c between 52, Is to connect the welded portion 31, Center C1 of 32 The line LC1 between C2 is transversely cut, further, Put 2 lines LN1 The configuration of LN2 crosscutting is also possible. In the example shown in Figure 5, Heat affected part 51, The end 4 of the pair of flanges 1c between 52, Is to cross the line LC1, further, Also will be 2 lines LN1 LN2 cross cut. [0055] In the example shown in FIG. 5, Heat affected part 51, The end 4 of the pair of flanges 1c between 52, Is the line LG1 of 2 LG2 crosscut. Line LG1 and line LG2, It is an end portion of the field between the outer peripheral edge 51g of the heat-affected portion 51 and the outer peripheral edge 52g of the heat-affected portion 52 adjacent thereto. In this case, Heat affected part 51, The end 4 of the pair of flanges 1c between 52, Is the adjacent heat affected portion 51, Cross-sectional field between 52. thus, The heat-affecting portion 51 at the time of deformation toward the flange 1c can be effectively suppressed, 52 load. <Modification of Second Member> Fig. 6, It is a figure which shows the modification of the closing pallet 2 as an example of a 2nd member. In the heat-affected zone where the tensile strength of the closed pallet is not reduced, As shown in Figure 6, In the adjacent welded portion 31, Between 32, It is also possible that the ends of the closing pallet 2 are not crossed. Constructed accordingly, It is also possible to suppress the deformation of the flange 1c toward the heat-affected portion 51, 52 load. The tensile strength of the material of the closure pallet 2, It is preferably less than 980 MPa. thus, Around the welded portion 3, It is difficult to soften due to heat during welding. in this way, As the material of the closing pallet 2, It is preferable to select a material which does not generate a portion which is softened by the heat of soldering. which is, Closing pallet 2, Is around the welded part 3, No heat affected portion is preferred. When there is no heat affected part of the tensile strength drop, When the deformation of the pallet 2 is closed, the fracture originating from the heat-affected portion is not caused. [0057] As mentioned above, In the cap member 1, A high-strength material having a tensile strength of 980 MPa or more is used. here, In the cap member 1, In the heat affected portion 51 of the flange 1c, The ends of the pair of flanges 1c are disposed between 52. For this, In the closure pallet 2, Use materials that do not produce heat affected parts. In the closure pallet 2, Between the welded parts 3, No end is set. thus, When the cap member 1 uses a high-strength material, The strength as the structural material 10 can be ensured. further, It is possible to suppress breakage caused by the softened portion which occurs by using a high-strength material. [0058] Figure 7, It is a section showing the vicinity of the welded portion when the tensile strength of the closed pallet 2 is less than 1180 MPa. And an example of the distribution of Vickers hardness. In Figure 7, The upper part of Figure 7, It is a cross-sectional view of a part including the welded portion 3. In the lower part of Figure 7, It is a graph showing the distribution of the Vickers hardness of the line S and the line S1 in the cross-sectional view. In this chart, Line T1, Is the distribution of the Vickers hardness in the display line S, Line T2, It is the distribution of the Vickers hardness in the display line S1. [0059] As shown in FIG. 7, The tensile strength of the welded portion 3 is lower than the hardness of the cap member 1. This is because the cap member 1 and the closure plate 2 are melted and mixed into the welded portion 3, It has a lower hardness than the cap member 1. An area affected by heat adjacent to the welded portion 3 of the cap member 1, It is the same hardness as the cap member 1 (base metal). The field of heat affected by the field separated from the welded portion 3 of the hat member 1, The hardness is lowered as compared with the cap member 1. The hardness distribution of the heat-affected zone 5 of the hat-shaped member 1 is the same as that of FIG. The hardness of the welded portion 3 on the side of the closing plate 2 is equal to the hardness of the cap member 1. The hardness of the field affected by the heat around the welded portion 3 on the side of the closing pallet 2 is lowered as it goes away from the welded portion 3. This is because the cooling rate after welding is lowered as it goes away from the welded portion 3. The cooling rate is close to the field of the welded portion 3, This is because of the heat extraction caused by the spot welded electrode. In the closing pallet 2, there is no heat-affected portion having a hardness lower than 50Hv or more than the closing pallet 2. <Modification of First Member and Second Member> FIG. 8A, It is a cross-sectional view which shows the modification of the cross-sectional shape of a structural material. The cross-sectional shape of the structural material 10a shown in Fig. 1D, It is a shape that is bilaterally symmetrical with respect to the vertical two-division surface (the surface including the x-axis) of the closing pallet 2. For this, The structural material 10a shown in Fig. 8A, It is asymmetrical to the left and right bisectors of the closed pallet 2. The hat member 1 of the structural material 10a shown in Fig. 8A, It is two side walls 1b having different shapes from each other. 2 side walls 1b, Its angle to the flange 1c, And the height HR in the z direction, HL is different from each other. [0061] In the example shown in FIG. 8A, One side wall 1b of one of the two side walls 1b, It has a step difference. And, The other side wall 1b of the two side walls 1b, It is a shape that is curved in an arc. in particular, a portion extending from the first curved portion 1ab of the other side wall 1b, Form R (arc). [0062] Again, Although not shown, Top face 1a, Side wall 1b, At least one surface of the flange 1c and the closing bracket 2, It is not a plane but a curved surface. which is, Top face 1a, Side wall 1b, At least one of the flange 1c and the closing pallet 2, Even if it is curved, it can be. [0063] In Figure 8A, The illustration of the heat affected portion is omitted. the following, 9A to 14th (except for the 11B), The illustration of the heat affected portion is also omitted. [0064] and in the example shown in FIG. 8A, Closing pallet 2, It has a shape that protrudes in a direction away from the cap member 1. in particular, Closing pallet 2, Yes contains: a portion 2b overlapping the flange 1c of the cap member 1, And the portion 2a between these portions 2b. This part 2a, It is a shape that protrudes in a direction away from the cap member 1. In this case, The cross-sectional shape of the closing pallet 2 is a hat type. thus, A structural material that forms a double-hat shape. In the configuration shown in Fig. 8A, The cap member 1 is used as the first member, It is also possible to use the closing pallet 2 as the second member. Or the cap member 1 is used as the second member, The closing pallet 2 may be used as the first member. [0065] FIG. 8B, It is a cross-sectional view of another modification which shows the cross-sectional shape of a structural material. In the example shown in Figure 8B, Can replace the cap member with two flanges, A groove type member including one flange is used. The structural material 10b shown in Fig. 8B, Is with: Grooved grooved member 13, And closed pallet 2 And a welded portion 3r that joins the groove member 13 and the closing plate 2, 3h. Groove member 13, Yes with: Top face 1a, And a first side wall 1br and a second side wall 1bh extending from both ends of the top surface portion 1a. The first side wall 1br and the second side wall 1bh, They are facing each other. [0066] The flange 1c extends outward from the end portion on the opposite side of the top surface portion 1a of the first side wall 1b. The curved portion 1bcr is provided at the boundary between the first side wall 1br and the flange 1c. Flange 1c, It is overlapped with the closing pallet 2 and joined by the welded portion 3r. In the portion 1bhd including the end portion on the opposite side of the top surface portion 1a of the second side wall 1bh, The closure pallets 2 are overlapped. Part 1bhd and closed pallet 2, It is joined by the welded portion 3h. Closing pallet 2, The end portion of the portion 2bh overlapping the second side wall 1bh has a curved portion 2abh. [0067] Again, Groove member 13, It is also possible without flanges. In the configuration shown in Fig. 8B, The groove member 13 is an example of the first member. The closing pallet 2 is an example of the second member. Structural material 10b, Yes contains: Closed section 102, And a flange 101r disposed on the outer side of the closed cross-sectional portion 102, 101h. At the flange 101r, 101h, Forming a welded portion 3r, 3h. In the welding part 3r, The surrounding channel member 13 of 3h has a heat-affected portion (not shown). [0068] Again, As shown in Figure 8C, Forming the flange 101 of the welded portion 3, It may be disposed on the inner side of the closed cross-sectional portion 102. In the structural material 10c shown in Fig. 8C, Flange 101, A part of the closed section 102 is formed. Structural material 10c, It is provided with the groove type member 13 and the closing pallet 2. Groove member 13, Yes with: Top face 1a, And a side wall 1b extending from the both ends of the top surface portion 1a facing each other, And a flange 1c that extends close to each other from the opposite side of the top surface portion 1a of the side wall 1b. Flange 1c, It overlaps with the closing pallet 2. In the configuration shown in Fig. 8C, The hat member 1 is an example of the first member. The closing pallet 2 is an example of the second member. [0069] Figure 9, It is a cross-sectional view showing an example of a structural material obtained by joining three sheets. The structural material 10d shown in Fig. 8, It is for the structural material 10 shown in Fig. 1D, Providing the closing pallet 2 on the opposite side of the hat member 1 Another cap member 11 is further provided. Cap member 11, It is the same as the cap member 1, Having a top surface portion 11a, Side wall 11b, And the flange 11c. The flange 1c of the cap member 1, Three of the closing bracket 2 and the flange 11c of the cap member 11 are overlapped and joined by the welded portion 3. in this way, The number of the plates constituting the structural material is not limited to two. And, The number of the plate portions that are overlapped and joined is not limited to two. Structural material, It is also possible to have a configuration in which three or more plates are overlapped and joined by a welded portion. In the configuration shown in Fig. 9, Cap type member 1, At least one of 11 is the first member, The closing pallet 2 may be used as the second member. [0070] Figure 10, It is a sectional view of the structural material of a modification. The structural material 10e shown in Fig. 10, Yes with: With three curved portions 12bb, The first board of 12bc 12, The flat plate having no curved portion is also the second plate 22. Structural material 10e, Yes with: Closed section 102, And a joint plate portion 101 that protrudes toward the outer side of the closed cross-sectional portion 102. In the joint plate portion 101, The first plate 12 and the second plate 22 are overlapped. And combined by welding. In the configuration shown in Fig. 10, The first plate 12 is used as the first member, The second plate 22 may be used as the second member. Or the first board 12 is used as the second member, The second plate 22 may be used as the first member. in this way, a plate that forms a closed section, It is not limited to those having the top surface portion 1a as shown in Figs. 1A to 1D. A closed section can be constructed using a plate having other curved portions. <Modification of Structural Material> FIG. 11A, It is a sectional view of the structural material of a modification. Figure 11B, It is a top view seen from the z direction of the structural material shown in FIG. 11A. The structural material 10f shown in Figs. 11A and 11B, It is a structure that does not have a closed profile. Structural material 10f, Is with: The first plate 13 having the curved portion 13bc, And does not have the curved second plate 23. First plate 13 and second plate 23, Are overlapping each other, It is composed of the welded portion 3. Tensile strength of the first plate 13, It is 980 MPa or more. [0072] The first board 13, The first joining plate portion 13c and the first separating plate portion 13b are included. First bonding plate portion 13c, It is joined to the second plate 23 so as to overlap. The first separating plate portion 13b, It is from the end of the first joint plate portion 13c, The joint surface of the first plate 13 and the second plate 23 extends in a direction having a surface having a predetermined angle (a substantially right angle in this example). The boundary between the first joining plate portion 13c and the first separating plate portion 13b, It is the curved part 13bc which becomes the 1st board 13. [0073] the first bonding plate portion 13c and the second plate 23, Are in contact with each other, It is joined by the welded portion 3. Welding part 3, It is a welded portion that is a portion that integrates a part of the first plate 13 and a part of the second plate 23 by welding. As shown in Figure 11B, In the first joint plate portion 13c and the second plate 23, A plurality of welded portions 3 (spot welded portions) are provided. In each circumference of the plurality of welded portions 3 of the first joint plate portion 13c, It has a heat affected portion 5. Between adjacent heat affected portions 5, A pair of end portions 4 of the first joint plate portion 13c are disposed. a pair of end portions 4 of the first coupling plate portion 13c, A discontinuity is formed between the adjacent heat-affected portions 5. [0074] a plurality of welded portions 3 and heat affected portions 5, It is arranged in parallel in the direction (x direction) in which the ridgeline of the curved portion 13bc extends. a pair of end portions 4 of the first coupling plate portion 13c, It is a part of the slit (notch) that enters from the end on the opposite side of the curved portion 13bc of the first joint plate portion 13c toward the curved portion 13bc. Slotted, It does not extend to the curved portion 13bc. in particular, a curved portion between the first joining plate portion 13c and the first separating plate portion 13b, And areas that do not overlap from the z direction, Form a slit. which is, An end portion connecting the pair of end portions 4 of the first joint plate portion 13c between the adjacent heat affected portions, It is not disposed so as to intersect the end portion 13f on the side of the first coupling plate portion 13c of the R of the curved portion 13bc. [0075] Thus, Structural material, It is also possible to have a closed profile structure. And, Structural material, It may be formed of a plate having no bent portion. E.g, In the configuration shown in Fig. 11A, Put the first board 13, It is also possible to replace it with a flat plate having no bent portion. In this case, The welded portion 3 and the pair of end portions 4, Is for example, It may be arranged in the same manner as in Fig. 11B. In the configurations shown in FIGS. 11A and 11B, The first plate 13 is used as the first member, The second plate 23 may be used as the second member. Or the first board 13 is used as the second member, The second plate 23 may be used as the first member. [0076] Figure 12, It is a sectional view of the structural material of a modification. The structural material 10g shown in Fig. 12, One of the plates 14 is bent to form a tubular portion (closed section 102). [0077] one plate 14 constituting the structural material 10g, It is a plate portion that is joined to each other in an overlapping manner, The first plate portion 14a and the second plate portion 14e are included. The first plate portion 14a and the second plate portion 14e, It is a part including the end of one plate 14 . The first plate portion 14a and the second plate portion 14e that overlap each other, Is continuous with the closed section 102, The flange 101 disposed on the outer side of the closed cross-sectional portion 102 is formed. which is, In the example shown in Figure 12, With one plate 14, The closed cross section 102 and the flange 101 are formed. [0078] The first plate portion 14a and the second plate portion 14e, It is joined by the welded portion 3. Although not shown in Fig. 12, Welding part 3, It is set by plural. A heat-affected zone is formed around the welded portion 3 of the first plate portion 14a and the second plate portion 14e. Between the adjacent heat affected portions of the first plate portion 14a, It is a pair of end parts provided with the 1st board part 14a. Between the adjacent heat affected portions of the second plate portion 14e, It is a pair of end parts provided with the 2nd board part 14e. In the first plate portion 14a and the second plate portion 14e, Welding part 3, Heat affected department, And the composition of the ends of a pair, Is for example, Can be compared with Figure 1B above, Figure 1C, The configuration of the first member in the second to sixth figures is the same. [0079] board 14, It is between the first plate portion 14a and the second plate portion 14e. Having a plurality of curved portions 14ab, 14bc, 14cd, 14de. The curved portion 14ab of these, 14bc, 14cd, The ridgeline formed by 14de, It is extending in the x direction. Although not shown, In the x direction, It is also possible to extend the length direction of the structural material 10g. In this case, Structural material 10g, It has a tubular portion that extends in the x direction. And, Multiple welds 3, Is disposed in the curved portion 14ab, 14bc, 14cd, The direction of the extension of the 14de ridgeline. An end portion connected between the pair of end portions formed between the adjacent heat-affected portions of the first plate portion 14a, It is formed without extending to the curved portion 14ab. [0080] Again, The shape of the closed section of the structural material, Not limited to a quadrangle, Other shapes including polygons or curves are also available. And, In the example shown in Figure 12, The plate portions overlapping each other are the flanges 101, It is disposed outside the closed section 102. other, As shown in Figures 13 and 14, Board parts that overlap each other, It may be formed in the closed section 102. [0081] In the structural material 10h shown in FIG. 13, Closed section 102, Is a plate portion 14a including overlaps, 14e. Plate portions 14a overlapping each other, 14e, It is joined by the welded portion 3. Although not shown in Figure 13, Welding part 3, It is configured in parallel in the x direction. In the plate portion 14a of the plurality of welded portions 3, Around 14e, Has a heat affected part. In the plate portions 14a and 14e, A pair of end portions are disposed between the adjacent heat-affected portions. The composition of the ends of a pair, Is for example, Can be compared with Figure 1B above, Figure 1C, The second to sixth figures are the same. An end portion connecting the pair of end portions of the plate portion 14a and the plate portion 14e, Is not extending to the curved portion 14ab of the board 14, 14de is formed. [0082] The closed cross-sectional shape of the closed cross section formed by the one plate 14 is Not limited to a quadrangle. E.g, Can have a polygon, Round, A closed cross-sectional portion having a closed cross section such as an elliptical shape or the like is formed of one plate 14 . Figure 14, It is a view showing a configuration example in which the closed cross-sectional portion 102 having a circular closed cross section is formed by one plate 14 . <For the welded portion> Again, Forming a weld for the welded portion, Not limited to spot welding. E.g, By welding or arc welding produced by lasers, It is also possible to form a welded portion. Arc welding, And any of the weldings produced by the laser, When the tensile strength of the first member is 980 MPa or more, A heat affected portion can be generated around the welded portion. In this case, As in the above embodiment, Between the adjacent heat affected portions of the first member, It is preferable to arrange the ends of the pair of the first members. thus, The fracture with the heat-affected zone as a starting point can be suppressed. [0084] Figure 15, It is a figure which shows the example of the weld part generate|occur|produced by arc welding. In the example shown in Figure 15, In the welded portion 31 produced by arc welding, There is a heat affected portion 51 around 32, 52. In the adjacent heat affected portion 51, Between 52, A pair of end portions 4 of the flange 1c (first member) are disposed. The length direction of the welded portion produced by arc welding is taken as the longitudinal direction LB, A direction perpendicular to the longitudinal direction is referred to as a width direction LW. In the length direction to weld the portion 31, 32 the midpoint of the line that divides by 2, As the welding portion 31, Center C1 of 32 C2. In the example shown in Figure 15, Connecting the welded portion 31, A pair of end portions 4 are disposed transversely to the line of the center of 32. An end portion 4a connecting the pair of end portions 4, It is not to divide the R boundary 1f (the ridge portion of the first member). <Other Modifications> The joint surface of the steel sheet joined by the welded portion may be bent. Structural material, Is for example, In a direction perpendicular to the joint surface of the steel plate (or the plate portion), It is also possible to bend in a direction parallel to the joint surface (in-plane direction). Structural material, Is formed by a plate containing a bent portion, The ridge line formed by the curved portion may be linear, Bending is also possible. [0086] a plurality of welded parts, It is an example of a form in which the ridges of the curved portion are arranged side by side in the direction in which they extend. At least the welded portion of the plurality of welded portions, It is also possible to deviate from the configuration in a direction perpendicular to the ridgeline. also, Multiple welds, It may be arranged in parallel in a direction perpendicular to the direction in which the ridges of the curved portion extend. [Simulation result] Inventor, etc. It is simulated using a model of a structural member having a hat-shaped member and a closed pallet. The deformation behavior of the structural material at the time of the impact is analyzed. A simulation was performed using a complex model that changes the composition of the ends of the flanges in the construction material. simulation, The case where the cap member 1 collides with the pressing member in the z direction is performed. [0088] Figure 16, Is a diagram showing the model used for the simulation. Figure 17, It is a figure seen from the upper (z direction) of the structural member in the model shown in FIG. Figure 18, This is a cross-sectional view showing a cross section of the A-A line shown in Fig. 17. Figure 19, It is an enlarged view of the field E shown in Fig. 17. [0089] In the model shown in FIG. 16, The striker 17 is caused to collide from above the structural member having the cap member 41 and the closing bracket 42. Structural material, It is placed on the stage 19 which is juxtaposed in the longitudinal direction of the cap member 41. on the top, The cover 18 is a central portion that is coated between the stages 19 of the hat member 41. Cap member 41, Is having a top surface portion 41a, Side wall 41b and flange 41c. Flange 41c, Is overlapped on the closure pallet 42, Bonded by spot welding. Cover 18, It is in contact with the top surface portion 41a. Impactor 17, It is moving in the z direction and collides with the cover 18. [0090] As shown in FIG. 17, a welded portion 43 formed by spot welding, It is plural in parallel in the same direction (x direction) as the direction in which the ridgeline 41bc between the flange 41c and the side wall 41b extends. In each circumference of the plurality of welded portions 43, There is a heat affected portion 45. The intensity of the heat affected portion 45, It is set lower than the strength of the base material of the cap member. [0091] As shown in FIG. 18, In the inner side of the space surrounded by the cap member 41 and the closing bracket 42 A reinforcing member 46 that is in contact with the cap member 41 is disposed. Reinforcing member 46, The side wall 41b and the top surface portion 41a of the hat member 41 are joined by welding. Closing the pallet 42, It is curved along the curved portion between the flange 41c of the hat member 41 and the side wall 41b. The tensile strength of the cap member 41 of the Fig. 17 and the metal plate of the closing bracket 42 is 1470 MPa. The plate thickness is 1. 4mm. The tensile strength of the metal plate of the reinforcing member 46 is 1470 MPa, and the thickness of the plate is 2. 0mm. [0092] As shown in FIG. 19, a notch is provided in the flange 41c. That is, a pair of end portions 44 of the flange 41c are disposed between the adjacent heat-affected portions 45. The end portion 44 extends in the y direction. The pair of end portions 44 of the flanges 41c between the adjacent heat-affected portions 45 are part of the notches. The diameter ND of the welded portion 43, the distance C between the centers of the welded portions 43, the length S between the end portions 44 of the flanges 41c on both sides of the welded portion 43 in the x direction, and the length α of the notched y direction The depth α of the notch, the length F of the flange 41c in the y direction, and the radius of curvature R of the corner of the notch are parameters included in the simulation. The radius of curvature R is a radius of curvature of a locus of an end portion connecting the pair of end portions 44 to each other. 20A to 20C are graphs showing simulation results at the time of collision of impactors when the length α of the notch in the y direction is changed. These graphs show α=0, α=(1/4)F, α=(1/2)F, α=(3/4)F, α=(1/2)F+(ND+1) The calculated value of each case of α=F and α=(5/4)F. Figure 20A shows the maximum shear force until the maximum load stroke of the impactor. Fig. 20B is a view showing a considerable plastic deformation of the deformation concentrated portion. Figure 20C is a diagram showing the considerable plastic deformation of the heat-affected zone. From the results shown in FIG. 20A, it is found that the length α of the notch in the y direction is larger than the distance between the center of the welded portion 43 and the edge of the flange 41c in the y direction (α>(1/2). In the case of F), the burden on the welded portion is reduced. From the results shown in Fig. 20B, it was found that the deeper the depth of the notch, the more the burden on the heat-affected portion is reduced. In particular, the length α of the notch in the y direction is larger than the distance between the center of the welded portion 43 and the edge of the flange 41c in the y direction (α>(1/2)F), and the heat affected portion The burden is greatly reduced. From the results shown in Fig. 20C, it was found that the deeper the notch depth, the more the deformation concentration toward the flange increases. 21A to 21C are graphs showing simulation results when the striker collides with the length S between the end portions 44 on both sides of the welded portion 43 in the x direction. These charts are shown as S=26. 6 mm, and S=15. Calculated value for each case of 3 mm. Figure 21A shows the maximum shear force until the maximum load stroke of the impactor. Fig. 21B is a view showing a considerable plastic deformation of the deformation concentrated portion. Figure 21C is a diagram showing the considerable plastic deformation of the heat-affected zone. From the results shown in FIG. 21A, it is found that the larger the length S, the more the burden toward the welded portion increases. From the results shown in Fig. 21B, it was found that the larger the length S, the more the deformation concentration toward the flange increases. From the results shown in Fig. 21C, it was found that the influence of the burden on the heat-affected portion toward the length S was almost absent. 22A to 22C are graphs showing simulation results at the time of collision of impactors when the radius of curvature R of the corner portion of the notch is changed. These graphs are calculated values for each case showing R=0, R=5 mm, and R=10 mm. Figure 22A shows the maximum shear force until the maximum load stroke of the impactor. Fig. 22B is a view showing a considerable plastic deformation of the concentrated portion of the deformation. Figure 22C is a diagram showing the considerable plastic deformation of the heat-affected zone. [0098] From the results shown in FIG. 22A, it was found that the influence of the welded portion of the radius of curvature R toward the corner portion of the notch was scarce. From the results shown in Fig. 22B, it was found that the larger the radius of curvature R of the corner portion of the notch, the more the concentration concentration toward the flange increases. From the results shown in Fig. 22C, it was found that the influence of the burden on the heat-affected zone of the radius of curvature R of the corner portion of the notch was scarce. [0099] The above-described structural material is a structural material that can be optimally used in deformation and destruction. In particular, when it is applied to the deformation and destruction of the assumed structural material in the present invention, since the welded portion is not easily broken, a structural material which is not easily broken can be obtained. Examples of the deformation and destruction of the assumed structural material can be exemplified for the vehicle structural material. The structural material for the vehicle, specifically, the front frame, the rear frame, the side sill, the front pillar, the center pillar, the cross member, the side rail, the air duct, the bumper reinforcement, and other various reinforcing members (reinforcing members) Frame parts of the car structure. Further, the present invention is also applicable to a plate component of an automobile structure of a side plate, a fender, a collision plate, a pedal, and a center plate. Since these automobile structures are deformed and destroyed in the event of a car collision, the effects of the present invention can be exerted. When the structural material of the present invention is used as a structural material for a vehicle, for example, the direction in which the welded portions of the structural material are arranged or the direction in which the curved portion extends may be a structural material disposed along the outer shape of the vehicle. In other words, the direction in which the welded portions of the structural material are arranged or the direction in which the curved portion extends may be such that the structural material is disposed substantially perpendicularly intersecting the impact from the outside of the vehicle. Thereby, even if the structural material is subjected to an impact from the outside of the vehicle, the welded portion can be more difficult to be broken. As described above, the above-described structural material is used as a vehicle structural member and a vehicle including the above-described structural material is also included in the embodiment of the present invention. [0101] In the construction material of the present invention, the number of pairs of adjacent welded portions may be plural. That is, the number of pairs of adjacent heat-affected portions of the first member may be plural. In this case, in at least a part of the logarithm of the plurality of heat-affected portions, the pair of end portions of the first member are provided between the adjacent heat-affected portions. Further, the material of the second member is not limited to the steel material. For example, the material of the second member may be other metals such as steel or aluminum. [0102] Although an embodiment of the present invention has been described above, the above-described embodiments are merely examples for implementing the present invention. Therefore, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be suitably modified without departing from the spirit and scope of the invention.

[0103][0103]

1，11‧‧‧帽型構件1,11‧‧‧Cap type components

1a‧‧‧頂面部1a‧‧‧Top face

1ab‧‧‧第1彎曲部1ab‧‧‧1st bend

1b‧‧‧側壁1b‧‧‧ side wall

1bc‧‧‧第2彎曲部1bc‧‧‧2nd bend

1bcr‧‧‧彎曲部1bcr‧‧‧bend

1bh‧‧‧側壁1bh‧‧‧ side wall

1bhd‧‧‧部分1bhd‧‧‧ part

1br‧‧‧側壁1br‧‧‧ side wall

1c‧‧‧凸緣1c‧‧‧Flange

1e‧‧‧R交界1e‧‧‧R junction

1f‧‧‧R交界1f‧‧‧R junction

2‧‧‧封閉托板2‧‧‧Closed pallet

2a‧‧‧部分2a‧‧‧Parts

2abh‧‧‧彎曲部2abh‧‧‧Bend

2b‧‧‧部分2b‧‧‧section

2bh‧‧‧部分2bh‧‧‧section

3，31，32‧‧‧焊接部3,31,32‧‧‧Welded parts

3r，3h‧‧‧焊接部3r, 3h‧‧‧welding department

4‧‧‧端部4‧‧‧ End

4a‧‧‧端部4a‧‧‧End

5‧‧‧熱影響部5‧‧‧The Ministry of Thermal Impact

10，10a～10g‧‧‧構造材10,10a～10g‧‧‧Structural materials

11‧‧‧帽型構件11‧‧‧Cap type components

11a‧‧‧頂面部11a‧‧‧Top face

11b‧‧‧側壁11b‧‧‧ side wall

11c‧‧‧凸緣11c‧‧‧Flange

12‧‧‧第1板12‧‧‧1st board

12bb，12bc‧‧‧彎曲部12bb, 12bc‧‧‧bend

13‧‧‧第1板13‧‧‧1st board

13‧‧‧溝型構件13‧‧‧ trench members

13b‧‧‧第1分離板部13b‧‧‧1st separation board

13bc‧‧‧彎曲部13bc‧‧‧Bend

13c‧‧‧第1結合板部13c‧‧‧1st joint plate

13c‧‧‧結合板部13c‧‧‧Combined board

13f‧‧‧端部13f‧‧‧End

14‧‧‧板14‧‧‧ board

14a‧‧‧第1板部14a‧‧‧1st Board

14ab，14bc，14cd，14de‧‧‧彎曲部14ab, 14bc, 14cd, 14de‧‧‧bend

14e‧‧‧第2板部14e‧‧‧2nd Board

17‧‧‧撞擊器17‧‧‧ impactor

18‧‧‧蓋18‧‧‧ Cover

19‧‧‧台19‧‧‧

22‧‧‧第2板22‧‧‧2nd board

23‧‧‧第2板23‧‧‧2nd board

41‧‧‧帽型構件41‧‧‧Cap type components

41a‧‧‧頂面部41a‧‧‧Top face

41b‧‧‧側壁41b‧‧‧ Sidewall

41bc‧‧‧稜線41bc‧‧‧ ridgeline

41c‧‧‧凸緣41c‧‧‧Flange

42‧‧‧封閉托板42‧‧‧Closed pallet

43‧‧‧焊接部43‧‧‧Weld Department

44‧‧‧端部44‧‧‧End

45‧‧‧熱影響部45‧‧‧The Ministry of Thermal Impact

46‧‧‧補強構件46‧‧‧Reinforcing components

51，52‧‧‧熱影響部51,52‧‧‧The Ministry of Thermal Impact

51g，52g‧‧‧外周緣51g, 52g‧‧‧ outer circumference

51n，52n‧‧‧內周緣51n, 52n‧‧‧ inner circumference

101‧‧‧結合板部101‧‧‧Combined board

101r，101h‧‧‧凸緣101r, 101h‧‧‧Flange

102‧‧‧閉剖面部102‧‧‧Closed section

[0009] 　　[第1A圖]顯示本實施例中的構造材的構成的立體圖。　　[第1B圖]將第1A圖所示的構造材從z方向所見的俯視圖。　　[第1C圖]第1B圖的圓B的部分的放大圖。　　[第1D圖]第1C圖的A-A線的剖面圖。　　[第2圖]顯示焊接部及熱影響部的剖面構造及硬度分布的例的圖。　　[第3圖]說明熱影響部之間的端部的配置例用的圖。　　[第4圖]說明熱影響部之間的端部的其他的配置例用的圖。　　[第5圖]說明熱影響部之間的端部的其他的配置例用的圖。　　[第6圖]顯示第2構件的變形例的圖。　　[第7圖]顯示第6圖所示的變形例中的剖面構造及硬度分布的圖。　　[第8A圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第8B圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第8C圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第9圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第10圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第11A圖]顯示構造材的變形例的剖面圖。　　[第11B圖]將第11A圖所示的構造材從z方向所見的俯視圖。　　[第12圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第13圖]顯示構造材的剖面形狀的變形例的剖面圖。　　[第14圖]顯示將具有圓形的閉剖面的閉剖面部由1枚的板形成的情況的構成例的圖。　　[第15圖]顯示由電弧焊接所形成的焊接部的例的圖。　　[第16圖]說明模擬的模型用的圖。　　[第17圖]將第16圖所示的模型的構造材從z方向所見的圖。　　[第18圖]顯示第17圖中的A-A線的剖面的剖面圖。　　[第19圖]第17圖中的領域E的放大圖。　　[第20A圖]顯示將缺口的y方向的長度α變化的情況的解析結果的圖表。　　[第20B圖]顯示將長度α變化的情況的解析結果的圖表。　　[第20C圖]顯示將長度α變化的情況的解析結果的圖表。　　[第21A圖]顯示將x方向中的焊接部的兩側的端部4之間的長度S變化的情況的解析結果的圖表。　　[第21B圖]顯示將長度S變化的情況的解析結果的圖表。　　[第21C圖]顯示將長度S變化的情況的解析結果的圖表。　　[第22A圖]顯示將缺口的角部的曲率半徑R變化的情況的解析結果的圖表。　　[第22B圖]顯示將曲率半徑R變化的情況的解析結果的圖表。　　[第22C圖]顯示將曲率半徑R變化的情況的解析結果的圖表。[FIG. 1A] A perspective view showing a configuration of a structural material in the present embodiment. [Fig. 1B] A plan view of the structural material shown in Fig. 1A seen from the z direction. [Fig. 1C] An enlarged view of a portion of a circle B in Fig. 1B. [Fig. 1D] A cross-sectional view taken along line A-A of Fig. 1C. [Fig. 2] A view showing an example of a cross-sectional structure and a hardness distribution of a welded portion and a heat-affected portion. [Fig. 3] A diagram for explaining an example of arrangement of end portions between heat-affected portions. [Fig. 4] A view for explaining another arrangement example of the end portions between the heat-affected portions. [Fig. 5] A view for explaining another arrangement example of the end portions between the heat-affected portions. Fig. 6 is a view showing a modification of the second member. [Fig. 7] A view showing a cross-sectional structure and a hardness distribution in a modification shown in Fig. 6. [Fig. 8A] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 8B] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 8C] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 9] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 10] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 11A] A cross-sectional view showing a modification of the structural material. [Fig. 11B] A plan view of the structural material shown in Fig. 11A as seen from the z direction. [12] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 13] A cross-sectional view showing a modification of the cross-sectional shape of the structural material. [Fig. 14] Fig. 14 is a view showing a configuration example in which a closed cross-sectional portion having a circular closed cross section is formed of one plate. [Fig. 15] A view showing an example of a welded portion formed by arc welding. [Fig. 16] A diagram for explaining a model to be simulated. [Fig. 17] A view of the structural material of the model shown in Fig. 16 as seen from the z direction. [Fig. 18] A cross-sectional view showing a cross section taken along line A-A in Fig. 17. [Fig. 19] An enlarged view of the field E in Fig. 17. [Fig. 20A] A graph showing an analysis result of a case where the length α of the notch in the y direction is changed. [Fig. 20B] A graph showing the analysis result of the case where the length α is changed. [Fig. 20C] A graph showing the analysis result of the case where the length α is changed. [21A] A graph showing an analysis result of a case where the length S between the end portions 4 on both sides of the welded portion in the x direction is changed. [FIG. 21B] A graph showing an analysis result of a case where the length S is changed. [21C] A graph showing an analysis result of a case where the length S is changed. [Fig. 22A] A graph showing an analysis result of a case where the radius of curvature R of the corner portion of the notch is changed. [Fig. 22B] A graph showing an analysis result of a case where the radius of curvature R is changed. [22C] A graph showing an analysis result of a case where the radius of curvature R is changed.

Claims

A structural material comprising: a first member of a steel sheet having a tensile strength of 980 MPa or more; a second member of a metal plate overlapping the first plate portion; and the first member and the second member being welded by the second member a plurality of connected welded portions and the first member formed around each of the plurality of welded portions, and the Vickers hardness is a plurality of heat-affected portions having a Vickers hardness lower than a Vickers hardness of the first member by 50 HV or more, and the adjacent ones A pair of end portions of the first member extending between the heat-affected portions in a direction transverse to a line connecting the adjacent welded portions.

The structural material according to claim 1, wherein the pair of end portions are cross-sectional views of a line connecting the centers of the adjacent welded portions.

The structural material according to claim 2, wherein the pair of end portions are transversely cross-sectionally formed at an end portion of the region between the inner peripheral edges of the adjacent heat-affected portions.

A structural material according to claim 3, wherein the pair of end portions are transversely cross-sectionally formed between the adjacent heat-affected portions.

The structural material according to any one of claims 1 to 4, wherein the end of the pair is the edge of the hole formed in the first member.

The structural material according to any one of claims 1 to 5, wherein the second member has a tensile strength of less than 1180 MPa, and is not present in the second member between the adjacent welded portions. Ends.

The structural material according to any one of the first to fifth aspects of the present invention, wherein the second member is a steel sheet having a tensile strength of 980 MPa or more, and further includes a joint between the adjacent welded portions A pair of end portions of the second member extending in a direction transverse to the line of the adjacent welded portion.

The structural material according to any one of the first to sixth aspect, wherein the second member around the plurality of welded portions has no Vickers hardness lower than a hardness of the second member by 50 HV or more. Department of influence.

The structural material according to any one of the first to eighth aspects of the present invention, wherein a distance between one of the welded portions on an end portion of the pair of the welded portions is a diameter of the welded portion 6 times or less.

The structural material according to any one of the items 1 to 9 wherein the trajectory of the end portion connecting the end portions of the pair of the first portion is 10 mm or less.

The structural material according to any one of claims 1 to 10, wherein the first member includes a ridge portion, and an end portion of the pair and an end portion connected to the pair of end portions are not the aforementioned The ridge line is partially broken.