JP3243987B2 - Manufacturing method of high strength and high corrosion resistance martensitic stainless steel - Google Patents
Manufacturing method of high strength and high corrosion resistance martensitic stainless steelInfo
- Publication number
- JP3243987B2 JP3243987B2 JP28969295A JP28969295A JP3243987B2 JP 3243987 B2 JP3243987 B2 JP 3243987B2 JP 28969295 A JP28969295 A JP 28969295A JP 28969295 A JP28969295 A JP 28969295A JP 3243987 B2 JP3243987 B2 JP 3243987B2
- Authority
- JP
- Japan
- Prior art keywords
- stainless steel
- corrosion resistance
- test
- hot
- rolling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229910001105 martensitic stainless steel Inorganic materials 0.000 title claims description 22
- 238000005260 corrosion Methods 0.000 title description 37
- 230000007797 corrosion Effects 0.000 title description 35
- 238000004519 manufacturing process Methods 0.000 title description 20
- 239000000463 material Substances 0.000 claims description 47
- 238000005096 rolling process Methods 0.000 claims description 28
- 238000010791 quenching Methods 0.000 claims description 13
- 230000000171 quenching effect Effects 0.000 claims description 13
- 230000009467 reduction Effects 0.000 claims description 9
- 230000001186 cumulative effect Effects 0.000 claims description 7
- 229910052748 manganese Inorganic materials 0.000 claims description 7
- 229910052720 vanadium Inorganic materials 0.000 claims description 6
- 229910052758 niobium Inorganic materials 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 238000012360 testing method Methods 0.000 description 38
- 229910000831 Steel Inorganic materials 0.000 description 34
- 239000010959 steel Substances 0.000 description 34
- 229910001220 stainless steel Inorganic materials 0.000 description 23
- 239000010935 stainless steel Substances 0.000 description 22
- 238000000034 method Methods 0.000 description 19
- 239000000047 product Substances 0.000 description 15
- 238000001953 recrystallisation Methods 0.000 description 13
- 230000000694 effects Effects 0.000 description 11
- 238000005098 hot rolling Methods 0.000 description 8
- 229910000859 α-Fe Inorganic materials 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 238000012545 processing Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 5
- 238000005728 strengthening Methods 0.000 description 5
- 238000005496 tempering Methods 0.000 description 5
- 238000009864 tensile test Methods 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000002708 enhancing effect Effects 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229910001111 Fine metal Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000004881 precipitation hardening Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高強度高耐食性マ
ルテンサイト系ステンレス鋼材の製造方法に関し、さら
に詳しくは、船舶や建築物の構造材などに好適な厚鋼
板、形鋼などの鋼材を製造する方法であって、熱間加工
の際に割れ等の疵を生じさせることなく、強度、靱性、
伸び、耐食性、溶接性等の材料特性に優れたマルテンサ
イト系ステンレス鋼材を製造する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high-strength, high-corrosion-resistant martensitic stainless steel material, and more particularly to a method for producing a steel material such as a thick steel plate or a shape steel suitable for a structural material of ships and buildings. It is a method that does not cause defects such as cracks during hot working, strength, toughness,
The present invention relates to a method for producing a martensitic stainless steel excellent in material properties such as elongation, corrosion resistance and weldability.
【０００２】[0002]
【従来の技術】マルテンサイト系ステンレス鋼の中で、
Ｃ含有率が低い材質は、溶接性が良好なため溶接構造物
にも適用可能である。しかし、一般のステンレス鋼に比
べるとＣｒ含有率が低いので、耐食性にやや劣るという
欠点がある。マルテンサイト系ステンレス鋼の耐食性を
改善することを目的として、Ｍｏが添加された高耐食性
鋼が開発されている。Ｍｏは、塩化物環境下において耐
食性を効果的に高める働きがあり、マルテンサイト系ス
テンレス鋼に対して、オーステナイト系のＳＵＳ３０４
に匹敵する耐食性を付与することも可能である。例え
ば、特開平３−１８８２４０号公報には、Ｃ、Ｎ、Ｃｒ
およびＮｉ含有率が適正化され、かつＭｏおよびＶが添
加された耐食性、耐エロージョン性および溶接性に優
れ、高い強度を備えたマルテンサイト系ステンレス鋼が
開示されている。2. Description of the Related Art Among martensitic stainless steels,
A material having a low C content has good weldability and can be applied to a welded structure. However, since the Cr content is lower than that of general stainless steel, there is a disadvantage that the corrosion resistance is slightly inferior. For the purpose of improving the corrosion resistance of martensitic stainless steel, high corrosion resistance steel to which Mo has been added has been developed. Mo has a function of effectively increasing corrosion resistance in a chloride environment, and has an effect on austenitic SUS304 with respect to martensitic stainless steel.
It is also possible to impart corrosion resistance comparable to that of. For example, JP-A-3-188240 discloses C, N, Cr
A martensitic stainless steel having an excellent corrosion resistance, erosion resistance, and weldability, and having high strength, in which the content of Ni and the content of Ni are optimized and Mo and V are added is disclosed.
【０００３】一般に、マルテンサイト系ステンレス鋼
は、熱間加工性に劣る。その理由は、マルテンサイト系
ステンレス鋼の熱間加工時の金属組織はオーステナイト
相であり、Ｃ、Ｃｒ、Ｎｉ等の含有率によっては少量の
δフェライト相が存在し、このδフェライト相が、熱間
加工性を著しく低下させるからである。このようなマル
テンサイト系ステンレス鋼に対して、耐食性を高めるこ
とを目的として、上記のようにＭｏが添加された場合に
は、さらに、熱間加工性が問題となる。[0003] Generally, martensitic stainless steel is inferior in hot workability. The reason is that the metal structure of the martensitic stainless steel during hot working is an austenitic phase, and a small amount of δ ferrite phase exists depending on the content of C, Cr, Ni, etc. This is because interworkability is significantly reduced. When Mo is added to such a martensitic stainless steel for the purpose of enhancing corrosion resistance as described above, hot workability becomes a further problem.
【０００４】Ｍｏは、溶鋼が凝固する際に、偏析する傾
向の強い元素であるとともに、フェライト相を安定化す
る働きがある。したがって、Ｍｏが添加された鋼塊また
はスラブの中心部には、Ｍｏが偏析し、δフェライト相
が残存しやすいので、熱間加工性が悪くなるためであ
る。仮りに、製品ではδフェライトが残存しないように
成分設計されているとしても、鋼塊またはスラブを熱間
加工する工程においては、δフェライトの熱間加工性へ
の影響を避けることは困難である。この他、Ｍｏは高温
における変形抵抗を高める作用を持っているため、変形
抵抗の観点からも熱間加工性に対しては悪影響を及ぼ
す。このような熱間加工性に劣る材料を熱間加工した場
合、例えば、圧延された鋼板には、耳割れが生じ製品と
しては使用できないという事態が起こる。Mo is an element that has a strong tendency to segregate when molten steel solidifies, and also has a function of stabilizing a ferrite phase. Therefore, Mo segregates in the center of the steel ingot or slab to which Mo is added, and the δ ferrite phase is likely to remain, so that the hot workability deteriorates. Even if components are designed so that δ ferrite does not remain in the product, it is difficult to avoid the influence of δ ferrite on hot workability in the step of hot working a steel ingot or slab. . In addition, Mo has an effect of increasing the deformation resistance at high temperatures, and thus has an adverse effect on the hot workability from the viewpoint of the deformation resistance. When such a material having inferior hot workability is hot worked, for example, a rolled steel sheet may have an edge crack and cannot be used as a product.
【０００５】なお、δフェライト相が製品に残留した場
合には、強度および靱性を低下させる傾向がある。When the δ ferrite phase remains in the product, the strength and toughness tend to be reduced.
【０００６】また、本発明が対象としている厚さ６〜８
０ｍｍ程度の鋼板あるいは形鋼等の鋼材で、Ｃ含有率の
低いマルテンサイト系ステンレス鋼の鋼材は、熱間加工
後、直接焼入れし、焼戻し処理する直接焼入れ・焼戻し
法（ＤＱＴ法）、あるいは熱間圧延後、一旦冷却した後
に焼入れおよび焼戻し処理を行う再加熱焼入れ・焼戻し
法（ＲＱＴ法）によって製造される。この熱処理によっ
て、マルテンサイト系ステンレス鋼の強度が発現する。
その強化機構は、焼戻し中に起こる析出強化ではなく、
固溶強化および加工とマルテンサイト変態によって導入
された転位による強化とされている。[0006] The thickness of the present invention is 6 to 8
A steel material such as a steel sheet or a section steel having a carbon content of about 0 mm and a martensitic stainless steel having a low C content is directly quenched and then tempered after hot working, and is directly quenched and tempered (DQT method) or After the cold rolling, it is manufactured by a reheating quenching / tempering method (RQT method) in which quenching and tempering treatment is performed after cooling once. By this heat treatment, the strength of the martensitic stainless steel is developed.
The strengthening mechanism is not precipitation strengthening that occurs during tempering,
It is described as solid solution strengthening and strengthening by dislocations introduced by processing and martensitic transformation.
【０００７】ＤＱＴ法の場合には、加工組織が残ってい
る状態で焼入れされるので、微細な金属組織が得られ
る。そのために、一般に、ＤＱＴ法ではＲＱＴ法に比べ
ると、強度の高い製品が得られる。また、製造コストお
よび生産性の面でも、ＲＱＴ法より有利である。ただ
し、靱性、伸びはＲＱＴ法に比べて劣る傾向がある。In the case of the DQT method, quenching is performed in a state where a processed structure remains, so that a fine metal structure can be obtained. Therefore, in general, a product having higher strength can be obtained in the DQT method than in the RQT method. It is also more advantageous than the RQT method in terms of manufacturing cost and productivity. However, the toughness and elongation tend to be inferior to those of the RQT method.
【０００８】[0008]
【発明が解決しようとする課題】本発明は、上記の課題
を解決するためになされたものであって、熱間加工の際
に被加工材に割れ等の疵を生じさせることなく、強度、
靱性、伸び、耐食性、溶接性等の材料特性に優れたマル
テンサイト系ステンレス鋼材を製造する方法を提供する
ことを目的としている。DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has the following advantages.
It is an object of the present invention to provide a method for producing a martensitic stainless steel excellent in material properties such as toughness, elongation, corrosion resistance, and weldability.
【０００９】[0009]
【課題を解決するための手段】本発明者らは、上記課題
を解決するために、ＳＵＳ ３０４並みの耐食性を備え
たＭｏを含有する低炭素マルテンサイト系ステンレス鋼
の製造方法について、検討を行った。実験室的に溶製し
た鋼塊の熱間加工性と微量成分の関係および熱間加工条
件と強度特性の関係を詳細に調査した結果、以下のよう
な新たな知見を得た。Means for Solving the Problems In order to solve the above problems, the present inventors have studied a method for producing a low carbon martensitic stainless steel containing Mo having corrosion resistance comparable to that of SUS 304. Was. The following new findings were obtained as a result of a detailed investigation of the relationship between the hot workability and trace components and the relationship between the hot working conditions and the strength properties of ingots ingots in the laboratory.
【００１０】 ＣおよびＮ含有率が低い場合には、Ｂ
を０．０００５〜０．００５重量％（以下、化学組成の
％表示は重量％を表す）含有させることにより、熱間加
工性を向上させることができる。When the C and N contents are low, B
In an amount of 0.0005 to 0.005% by weight (hereinafter,% in chemical composition represents% by weight), thereby improving hot workability.
【００１１】 製品の鋼材の強度は、再結晶を起こさ
ないオーステナイト領域での累積圧下率４０％以上の熱
間加工とその後の直接焼入れ・焼戻しによって、向上さ
せることができる。[0011] The strength of the steel material of the product can be improved by hot working with a cumulative rolling reduction of 40% or more in the austenite region where recrystallization does not occur, followed by direct quenching and tempering.
【００１２】 に記したＢを含む場合には、Ｂは熱
間加工中の再結晶を抑制する働きがあるので、比較的高
温域からの未再結晶圧延が可能である。したがって、Ｂ
は鋼材の強度向上にも有効である。また、鋼材の強度を
得ることを目的として、熱間圧延時の仕上げ温度を下げ
る必要がないので、炭化物の析出が抑制され、伸びおよ
び靭性の低下を防止することができる。In the case where B is contained, B has a function of suppressing recrystallization during hot working, so that non-recrystallization rolling from a relatively high temperature range is possible. Therefore, B
Is also effective in improving the strength of steel. Further, since it is not necessary to lower the finishing temperature during hot rolling for the purpose of obtaining the strength of the steel material, precipitation of carbides can be suppressed, and reduction in elongation and toughness can be prevented.
【００１３】 Ｔｉを０．００５〜０．０２％含有さ
せることにより、鋼塊の結晶粒を微細化させ、熱間加工
性を向上せせることができる。[0013] By containing 0.005 to 0.02% of Ti, the crystal grains of the steel ingot can be refined, and the hot workability can be improved.
【００１４】 ＴｉおよびＢを複合して含有させるこ
とにより、熱間加工性および靭性を同時に向上させるこ
とができる。[0014] The hot workability and the toughness can be simultaneously improved by including Ti and B in a combined manner.
【００１５】本発明は、上記知見を基に完成されたもの
であって、その要旨は、「重量％で、 Ｃ ：０．０４％以下、 Ｓｉ：１．０％以下 Ｍｎ：１．０％以下、 Ｃｒ：１１〜１４％、 Ｎｉ：４〜８％、 Ｍｏ：０．５〜４％、 Ｂ ：０．０００５〜０．００５％、 Ａｌ：０．００３〜０．１％ Ｃｕ：０〜０．５％、 Ｐ ：０．０４％以下、 Ｓ ：０．００５％以下、 Ｎ ：０．０４％以下、 Ｔｉ：０〜０．０２％、 Ｖ ：０〜０．５％、 Ｎｂ：０〜０．５％ を含有し、残部がＦｅおよび不可避の不純物からなるス
テンレス鋼を、熱間圧延における１０００℃以下の累積
圧下率４０％以上の条件で熱間圧延した後、直接焼入れ
する高強度高耐食性マルテンサイト系ステンレス鋼材の
製造方法。」にある。The present invention has been completed on the basis of the above findings, and the gist of the invention is as follows: "by weight, C: 0.04% or less, Si: 1.0% or less, Mn: 1.0%. Hereinafter, Cr: 11 to 14%, Ni: 4 to 8%, Mo: 0.5 to 4%, B: 0.0005 to 0.005%, Al: 0.003 to 0.1% Cu: 0 to 0 % 0.5 %, P: 0.04% or less, S: 0.005% or less, N: 0.04% or less, Ti: 0 to 0.02%, V: 0 to 0.5%, Nb: 0 ０．５0.5%, the balance being Fe and unavoidable impurities, hot-rolled under conditions of cumulative rolling reduction of not more than 1000 ° C. and not less than 40% in hot rolling, and then directly quenched. Method for producing high corrosion resistant martensitic stainless steel. "
【００１６】[0016]
【発明の実施の形態】本発明の製造方法に用いるマルテ
ンサイト系ステンレス鋼（以下、単に本ステンレス鋼と
記す）および本発明の製造方法について、以下に具体的
に説明する。BEST MODE FOR CARRYING OUT THE INVENTION The martensitic stainless steel used in the production method of the present invention (hereinafter simply referred to as the present stainless steel) and the production method of the present invention will be specifically described below.
【００１７】（Ａ）本ステンレス鋼の化学組成 Ｃ：Ｃ含有率は、溶接性および耐食性を確保するため
に、０．０４％以下とした。Ｃ含有率が０．０４％を超
えると溶接性および耐食性を損なう。また、Ｃ含有率が
０．０１％未満の場合には、耐力が低くなりすぎるの
で、９０ｋｇｆ／ｍｍ2 以上の耐力を得るためには、Ｃ
含有率０．０１％以上とするのが望ましい。(A) Chemical composition of the present stainless steel C: The C content is set to 0.04% or less in order to secure weldability and corrosion resistance. If the C content exceeds 0.04%, weldability and corrosion resistance are impaired. If the C content is less than 0.01%, the proof stress is too low. Therefore, to obtain a proof stress of 90 kgf / mm 2 or more,
It is desirable that the content be 0.01% or more.
【００１８】Ｓｉ、Ｍｎ：ＳｉおよびＭｎは、おもに溶
鋼の脱酸に用いられる元素である。Si, Mn: Si and Mn are elements mainly used for deoxidizing molten steel.
【００１９】ただし、ＳｉおよびＭｎ含有率が１％を超
えると、本ステンレス鋼の加工性を損なう場合があるの
で、それぞれ１％以下とした。Ａｌ等の他の脱酸元素に
よって、十分に脱酸される場合には、ＳｉおよびＭｎは
原料等から混入してくる程度の含有率でもよい。However, if the content of Si and Mn exceeds 1%, the workability of the stainless steel may be impaired. When sufficiently deoxidized by another deoxidizing element such as Al, the contents of Si and Mn may be such that they are mixed in from raw materials and the like.
【００２０】Ｃｒ：Ｃｒは、本ステンレス鋼の耐食性を
確保する上で重要な元素であり、１１％以上含有させる
ことが必要である。しかし、Ｃｒ含有率が１４％を超え
ると、δフェライト相が析出しやすくなるため、熱間加
工性および製品の靱性が低下するので、上限は１４％と
した。Cr: Cr is an important element for securing the corrosion resistance of the stainless steel, and it is necessary to contain 11% or more. However, if the Cr content exceeds 14%, the δ ferrite phase is likely to precipitate, and the hot workability and the toughness of the product are reduced. Therefore, the upper limit is set to 14%.
【００２１】Ｎｉ：Ｎｉは、熱間加工温度域において、
本ステンレス鋼の金属組織をオーステナイト相とするた
めに必須の元素である。そのために、４％以上必要であ
る。Ni: In the hot working temperature range, Ni:
It is an essential element to make the metal structure of the present stainless steel an austenitic phase. Therefore, 4% or more is required.
【００２２】しかし、含有率が８％を超えると、常温に
おいてもオーステナイト相が残留し、強度および靭性を
損なう原因になるので、Ｎｉ含有率の上限は８％とし
た。However, if the content exceeds 8%, an austenite phase remains even at room temperature, causing a loss of strength and toughness. Therefore, the upper limit of the Ni content is set to 8%.
【００２３】Ｍｏ：Ｍｏは、本ステンレス鋼の耐食性を
高めるために、必須の元素である。Mo: Mo is an essential element for increasing the corrosion resistance of the stainless steel.
【００２４】耐食性の向上には、０．５％以上必要であ
る。しかし、４％を超えると、δフェライトが析出しや
すくなり、また、高温における変形抵抗が高くなるため
に、熱間加工性を悪くし、さらに製品の鋼材の強度およ
び靭性を低下させる。したがって、Ｍｏ含有率の上限
は、４％とした。To improve the corrosion resistance, 0.5% or more is required. However, if it exceeds 4%, δ ferrite is likely to precipitate, and the deformation resistance at high temperatures is increased, so that the hot workability is deteriorated and the strength and toughness of the steel material of the product are reduced. Therefore, the upper limit of the Mo content is set to 4%.
【００２５】Ｂ：Ｂは、本ステンレス鋼を特徴付ける重
要な元素であり、熱間加工性および製品の鋼材の靭性を
高める上で必須である。この効果を発揮させるために
は、０．０００５％以上含有させる必要がある。しか
し、Ｂ含有率が０．００５％を超えると、１３００℃以
上の高温域で熱間脆性を引き起こすようになる。したが
って、本ステンレス鋼におけるＢ含有率は、０．０００
５〜０．００５％とした。B: B is an important element characterizing the present stainless steel, and is essential for enhancing hot workability and toughness of steel products. In order to exhibit this effect, it is necessary to contain 0.0005% or more. However, when the B content exceeds 0.005%, hot brittleness is caused in a high temperature region of 1300 ° C. or more. Therefore, the B content in the present stainless steel is 0.000
The content was 5 to 0.005%.
【００２６】先に記したように、本発明者らは、本ステ
ンレス鋼において、Ｂは熱間加工中の再結晶を抑制する
働きがあり、比較的高温域からの未再結晶加工を可能に
する効果を持っていることを知見した。その調査につい
て、以下に説明する。As described above, the present inventors have found that in the present stainless steel, B has a function of suppressing recrystallization during hot working, and enables unrecrystallization from a relatively high temperature range. It was found that it had the effect of doing. The investigation is described below.
【００２７】図１に、熱間圧縮加工条件と再結晶率５０
％の関係について調査した結果を示した。化学組成が本
発明の範囲内の供試材（実線）、Ｂは含まずその他の化
学組成が同一の供試材（点線）について、圧縮加工前の
保持時間を横軸に、圧縮加工温度を縦軸にとり、５０％
再結晶曲線を図示した。図１から明かなように、Ｂ：
０．００１０％（実線）を含有させることにより、Ｂ：
無添加（点線）の場合に比べて、未再結晶領域の温度は
少なくとも５０℃程度高くなる。すなわち、Ｂを含有す
ることにより、熱間加工の際の再結晶は抑制され、未再
結晶温度域は高温側に広がるので、再結晶を起こさせず
に加工することが可能な加工開始温度は、少なくとも５
０℃程度高くなるといえる。FIG. 1 shows the hot compression working conditions and the recrystallization ratio 50.
The results obtained by investigating the relationship of% are shown. For the test material whose chemical composition is within the scope of the present invention (solid line), and for the test material (dotted line) that does not contain B and has the same other chemical composition (dotted line), the holding time before compression processing is plotted on the horizontal axis, and the compression processing temperature is plotted. 50% on the vertical axis
The recrystallization curve is illustrated. As is evident from FIG. 1, B:
By containing 0.0010% (solid line), B:
The temperature of the unrecrystallized region is at least about 50 ° C. higher than the case of no addition (dotted line). That is, by containing B, recrystallization at the time of hot working is suppressed, and the non-recrystallization temperature region spreads to the high temperature side, so that the processing start temperature at which processing can be performed without causing recrystallization is , At least 5
It can be said that the temperature increases by about 0 ° C.
【００２８】なお、Ｂを含む場合、ステンレス鋼の耐粒
界腐食性が低下することが懸念されるので、ＪＩＳ Ｇ
０５７７に規定された試験条件に従って、孔食電位を測
定し耐粒界腐食性を評価した。試験には、本発明の製造
方法の条件で作製した供試材を用いた。When B is contained, there is a concern that the intergranular corrosion resistance of stainless steel may be reduced.
According to the test conditions specified in 0577, the pitting corrosion potential was measured to evaluate the intergranular corrosion resistance. For the test, a test material produced under the conditions of the production method of the present invention was used.
【００２９】図２に、Ｂ含有率と孔食電位の関係を示
す。Ｂ含有率が０．０００５％以上の場合には、Ｂを含
有しない場合に比べて孔食電位がやや高く、耐孔食性す
なわち耐粒界腐食性にはまったく問題がないことが明か
である。FIG. 2 shows the relationship between the B content and the pitting potential. When the B content is 0.0005% or more, the pitting potential is slightly higher than when B is not contained, and it is clear that there is no problem in pitting corrosion resistance, that is, intergranular corrosion resistance.
【００３０】このように、本ステンレス鋼におけるＢ
は、未再結晶温度域での調整圧延と直接焼入れとの組み
合わせにより、本発明の方法で得られる鋼材の強度の向
上を図る上で極めて有効である。また、熱間加工性を向
上させるので、従来問題であった熱延鋼板の耳割れ発生
等の防止にも有効である。As described above, B in the present stainless steel
Is extremely effective in improving the strength of the steel material obtained by the method of the present invention by a combination of controlled rolling and direct quenching in the non-recrystallization temperature range. Further, since the hot workability is improved, it is also effective in preventing the occurrence of edge cracks of a hot-rolled steel sheet, which has been a conventional problem.
【００３１】Ａｌ：Ａｌは溶鋼の脱酸力が非常に大きい
元素であり、通常、Ｓｉ、Ｍｎとともに添加される。本
ステンレス鋼の場合は、脱酸効果を得るために、０．０
０３％以上を必要とする。Ａｌを用いた脱酸によって、
本ステンレス鋼の酸化物系介在物は減少し、高い靭性が
得られる。一方、Ａｌ含有率が０．１％を超えると本ス
テンレス鋼の熱間加工性を低下させる場合がある。した
がって、Ａｌ含有率の上限は、０．１％とした。Al: Al is an element having a very large deoxidizing power of molten steel, and is usually added together with Si and Mn. In the case of this stainless steel, 0.0%
Requires more than 03%. By deoxidation using Al,
The oxide-based inclusions of the stainless steel are reduced, and high toughness is obtained. On the other hand, if the Al content exceeds 0.1%, the hot workability of the stainless steel may be reduced. Therefore, the upper limit of the Al content is set to 0.1%.
【００３２】Ｃｕ：Ｃｕは、不純物として０．０２％以
下含まれるが、本ステンレス鋼においては、析出硬化に
よる高強度化を図るために、必要に応じて不純物量を超
えて添加する元素である。ただし、Ｃｕ含有率が０．５
％を超えると、熱間加工性を低下させる。したがって、
Ｃｕを含有させる場合は、０．０２％を超え、０．５％
以下とするのが好ましい。Cu: Cu is 0.02% or less as an impurity.
Although included below, in this stainless steel, in order to increase the strength by precipitation hardening, the amount of impurities
Is an element which Ete added. However, when the Cu content is 0.5
%, The hot workability is reduced. Therefore,
If Cu is contained , exceed 0.02%, 0.5%
It is preferred to be
【００３３】Ｐ：Ｐは、原料等から不可避的に混入して
くる元素であり、本ステンレス鋼の靭性および耐食性に
有害である。したがって、その影響が現れない範囲であ
る０．０４％以下に制限することにした。P: P is an element unavoidably mixed from the raw material and the like, and is harmful to the toughness and corrosion resistance of the stainless steel. Therefore, it was decided to limit it to 0.04% or less, which is a range where the effect does not appear.
【００３４】Ｓ：ＳもＰと同様、原料等から不可避的に
混入してくる元素であり、本ステンレス鋼の熱間加工性
および靭性を低下させる。Ｓ含有率は低い方が好まし
く、０．００５％以下に制限した。S: Like P, S is an element unavoidably mixed from raw materials and the like, and reduces the hot workability and toughness of the stainless steel. The lower the S content, the better, and the S content is limited to 0.005% or less.
【００３５】Ｎ：Ｎ含有率が高い場合には、本ステンレ
ス鋼の溶接性および耐食性を害する傾向がある。そのた
めに、Ｎ含有率は、０．０４％以下とした。Ｎは、通常
の製造法によって不可避に混入してくる元素であり、下
限は特に規定しない。N: When the N content is high, the weldability and corrosion resistance of the stainless steel tend to be impaired. Therefore, the N content is set to 0.04% or less. N is an element that is unavoidably mixed by a normal production method, and the lower limit is not particularly defined.
【００３６】Ｔｉ：Ｔｉは、本ステンレス鋼の熱間加工
性と靭性を高める働きがあり、必要に応じて添加する元
素である。Ｔｉは、鋼塊またはスラブの結晶粒を微細化
し、Ｂとの併用で粒界強化をもたらすので、熱間加工性
と靭性の向上が得られる。この効果を発揮させるために
は、０．００５％以上を必要とする。ただし、過剰な場
合は、粗大なＴｉＮが析出し、靭性の低下が起こる。し
たがって、Ｔｉを添加する場合には、０．００５〜０．
０２％の範囲が好ましい。Ti: Ti has the function of enhancing the hot workability and toughness of the present stainless steel, and is an element added as necessary. Ti refines the crystal grains of the steel ingot or slab and brings about grain boundary strengthening in combination with B, so that hot workability and toughness can be improved. To exert this effect, 0.005% or more is required. However, if it is excessive, coarse TiN precipitates, and the toughness is reduced. Therefore, when Ti is added, 0.005 to 0.5.
A range of 02% is preferred.
【００３７】Ｎｂ、Ｖ：ＮｂおよびＶは、本ステンレス
鋼の強度を高めるとともに、耐食性を向上させるため
に、単独あるいは両者同時に必要に応じて添加する元素
である。その効果を得るためには、いずれも０．０１％
以上必要である。一方、０．５％を超えると靭性が低下
する。そのために、ＮｂおよびＶを含有させる場合に
は、いずれも含有率を０．０１〜０．５％とし、単独ま
たは両者を添加する。Nb, V: Nb and V are elements that are added singly or simultaneously as needed in order to increase the strength of the stainless steel and improve the corrosion resistance. To obtain the effect, 0.01%
It is necessary. On the other hand, if it exceeds 0.5%, the toughness decreases. Therefore, when Nb and V are contained, the content is set to 0.01 to 0.5% in both cases, and one or both of them are added.
【００３８】（Ｂ）熱間加工条件および焼入れ条件 本発明のマルテンサイト系ステンレス鋼材の製造方法
は、上記の化学組成を備えた本ステンレス鋼に、適正な
熱間加工条件と適正な熱処理条件を組み合わせることに
よって、優れた熱間加工性の基で、耐食性のよい高強度
の鋼材を製造することを特徴としている。(B) Hot working condition and quenching condition The method for producing a martensitic stainless steel material of the present invention is characterized in that a proper hot working condition and a proper heat treatment condition are applied to the present stainless steel having the above chemical composition. The combination is characterized in that a high-strength steel material having good corrosion resistance is manufactured based on excellent hot workability.
【００３９】本発明では、未再結晶温度領域における強
圧下によって得られた加工組織から、再結晶を起こさせ
ることなく、鋼材に直接焼入れ処理を施すことが、鋼材
の強度を向上させるために必須の条件である。本発明の
製造方法によって厚鋼板を製造する場合には、厚板粗バ
ー圧延が好適であり、この圧延では、リバース式で圧延
パス間時間が１０〜３０秒程度となる。前述の図１から
明かなように、この程度の時間を要する場合には、１０
００℃を越える温度領域における圧延では、加工組織は
次の圧延パスまでに再結晶を起こしてしまう。したがっ
て、加工組織を残した状態で圧延を終了させるために
は、１０００℃以下で圧延を行い加工歪を残す調整圧延
を含めることが重要である。この１０００℃以下での調
整圧延における累積圧下率が、少なくとも４０％となる
ようにし、十分な加工歪みを残した状態で冷却（焼入
れ）工程に入ることによって、製品の鋼材の強度を向上
させることが可能である。In the present invention, it is essential to directly harden the steel material without causing recrystallization from the processed structure obtained by applying a strong pressure in the non-recrystallization temperature range in order to improve the strength of the steel material. Is the condition. When a thick steel plate is manufactured by the manufacturing method of the present invention, thick plate rough bar rolling is suitable. In this rolling, the time between rolling passes is about 10 to 30 seconds in a reverse type. As is clear from FIG. 1 described above, when this time is required, 10
In rolling in a temperature range exceeding 00 ° C., the processed structure recrystallizes by the next rolling pass. Therefore, in order to finish the rolling with the processed structure remaining, it is important to include the adjustment rolling that is performed at a temperature of 1000 ° C. or lower to leave a processing strain. Improve the strength of the steel material of the product by entering the cooling (quenching) process while keeping the cumulative draft in the controlled rolling at 1000 ° C. or lower at least 40% and leaving sufficient working strain. Is possible.
【００４０】なお、調整圧延の温度の下限は特に制限し
ないが、析出物の増加による伸びおよび靱性の低下を防
止するために、８００℃程度とすることが好ましい。ま
た、調整圧延における累積圧下率の上限についても特に
制限しないが、熱間圧延素材と製品の鋼材の厚さまたは
断面積との関係によって制限される。Although the lower limit of the temperature for the adjustment rolling is not particularly limited, it is preferably about 800 ° C. in order to prevent a decrease in elongation and toughness due to an increase in precipitates. The upper limit of the cumulative rolling reduction in the adjustment rolling is not particularly limited, but is limited by the relationship between the hot-rolled material and the thickness or cross-sectional area of the steel product.
【００４１】[0041]
【実施例】実施例に基づいて、本発明の製造方法を具体
的に説明する。EXAMPLES The production method of the present invention will be specifically described based on examples.
【００４２】表１に、試験に用いた供試材の化学組成を
示す。供試材は、高周波誘導真空溶解炉によって溶製
し、厚さ４８ｍｍ、幅１９０ｍｍの偏平鋼塊に鋳造する
ことによって作製した。なお、供試材Ａ〜Ｅは本発明
例、Ｆ〜Ｉは比較例である。Table 1 shows the chemical compositions of the test materials used in the test. The test material was produced by melting in a high-frequency induction vacuum melting furnace and casting it into a flat steel ingot having a thickness of 48 mm and a width of 190 mm. The test materials A to E are examples of the present invention, and FI are comparative examples.
【００４３】[0043]
【表１】 [Table 1]
【００４４】上記の供試材について、熱間加工性、製品
の強度、耐食性等の材料特性を調査した。試験方法は、
下記の通りである。With respect to the above test materials, material properties such as hot workability, product strength, and corrosion resistance were examined. The test method is
It is as follows.
【００４５】１．熱間加工性 供試材の鋼塊から、径１０ｍｍ、長さ１３０ｍｍの平滑
丸棒引張試験片を採取し、熱間引張試験に供した。熱間
引張試験では、まず、直接通電加熱法により、試験片を
１２００℃に加熱し５分間保持した。次に、１００℃／
分の速度で、試験温度（１０００℃）まで冷却し、歪み
速度１／秒、クロスヘッド速度７ｍｍ／秒の条件で破断
させた。破断後の試験片について、断面収縮率を測定
し、熱間加工性を評価した。1. Hot workability A smooth round bar tensile test piece having a diameter of 10 mm and a length of 130 mm was collected from a steel ingot of the test material and subjected to a hot tensile test. In the hot tensile test, first, the test piece was heated to 1200 ° C. and held for 5 minutes by a direct current heating method. Next, at 100 ° C /
The sample was cooled to the test temperature (1000 ° C.) at a speed of 1 minute, and was broken under the conditions of a strain rate of 1 second and a crosshead speed of 7 mm / second. With respect to the test piece after the fracture, the cross-sectional shrinkage was measured and the hot workability was evaluated.
【００４６】２．熱間加工性および材料特性 供試材の鋼塊から、厚さ８５ｍｍ、幅１００ｍｍ、長さ
１５０ｍｍの熱間圧延用素材を採取した。この素材を１
２００℃に加熱し、１時間保持した後、１１００℃以上
の温度から圧延を開始した。その後、圧延途中の素材の
温度が１０００℃に下がった時点から圧延終了までの間
の累積圧下率が２５〜６０％となるように設定して、６
回のパスで厚さ２０ｍｍまで熱間圧延する調整圧延を行
った。熱間圧延後、スプレー水冷却により８００℃以上
の温度から１００℃まで圧延板を冷却することにより、
焼入れ（直接焼入れ）を行った。焼入れされた状態で、
圧延材に発生した疵を調査し、最大耳割れ深さを測定す
ることにより、熱間加工性を評価した。次に、焼入れさ
れた圧延材に対して、５５０℃の温度に３０分間保持す
る条件で、焼戻し処理を施した。この直接焼入れ・焼戻
し材から、各種試験片を採取し、それぞれの試験に供し
た。靱性の評価用として、ＪＩＳ Ｚ２２０２に規定さ
れている４号シャルピー試験片を板幅方向から採取し
（ノッチ方向は圧延方向）、−５０℃で衝撃吸収エネル
ギー（単位：Ｊ）を測定した。引張り強度等の特性評価
用として、ＪＩＳ Ｚ２２０１に規定されている１４Ａ
号引張試験片を圧延材の幅方向から採取し、室温におい
て、０．２％耐力、引張強さ（単位：ＭＰａ）を測定し
た。2. Hot workability and material properties A hot rolling material having a thickness of 85 mm, a width of 100 mm and a length of 150 mm was collected from a steel ingot of the test material. This material is 1
After heating to 200 ° C. and holding for 1 hour, rolling was started from a temperature of 1100 ° C. or higher. Thereafter, the rolling reduction was set so that the cumulative rolling reduction from the time when the temperature of the raw material during rolling dropped to 1000 ° C. to the end of rolling was 25 to 60%.
Adjustment rolling in which hot rolling was performed to a thickness of 20 mm in each pass was performed. After hot rolling, by cooling the rolled plate from a temperature of 800 ° C or higher to 100 ° C by spray water cooling,
Quenching (direct quenching) was performed. In the hardened state,
The hot workability was evaluated by examining the flaws generated in the rolled material and measuring the maximum edge crack depth. Next, a tempering treatment was performed on the quenched rolled material under the condition of maintaining the temperature at 550 ° C. for 30 minutes. Various test pieces were collected from the directly quenched and tempered materials and subjected to the respective tests. For the evaluation of toughness, a No. 4 Charpy test piece specified in JIS Z2202 was sampled from the sheet width direction (the notch direction was the rolling direction), and the impact absorption energy (unit: J) was measured at -50 ° C. 14A specified in JIS Z2201 for evaluating properties such as tensile strength
A tensile test specimen was taken from the width direction of the rolled material, and 0.2% proof stress and tensile strength (unit: MPa) were measured at room temperature.
【００４７】３．耐食性 上記の直接焼入れ・焼戻し材から、耐食性評価用として
孔食試験片を採取した。孔食試験の測定面は、圧延方向
に垂直な面とし、ＪＩＳ Ｇ０５７７に規定されている
試験条件によって、電流１００μＡ／ｃｍ2 の孔食電位
（単位：ｍＶ）を測定した。3. Corrosion resistance Pitting corrosion test pieces were collected from the above-mentioned direct quenched and tempered materials for corrosion resistance evaluation. The measurement surface of the pitting corrosion test was a surface perpendicular to the rolling direction, and the pitting potential (unit: mV) at a current of 100 μA / cm 2 was measured under the test conditions specified in JIS G0577.
【００４８】なお、比較例として、１２００℃に加熱し
て熱間圧延を行い、得られた圧延板を一旦常温まで冷却
した後、焼入れ（１０５０℃に３０分間保持後水冷）お
よび焼戻し（５５０℃に３０分間保持後空冷）を行うＲ
ＱＴ法により熱処理した試験材について、同様の試験を
実施した。As a comparative example, hot rolling was performed by heating to 1200 ° C., and the obtained rolled sheet was once cooled to room temperature, then quenched (maintained at 1050 ° C. for 30 minutes and then water-cooled) and tempered (550 ° C.). To cool for 30 minutes.
The same test was performed on the test material heat-treated by the QT method.
【００４９】表２に、これらの試験結果をまとめて示
す。Table 2 summarizes the results of these tests.
【００５０】[0050]
【表２】 [Table 2]
【００５１】表２から明かなように、供試材の化学組
成、熱間圧延の条件および熱処理の条件が本発明の範囲
内にある試験Ｎｏ．１〜６の本発明例では、耐力、引張
り強度、吸収エネルギーおよび孔食電位の値がいずれも
高く、十分な強度と靱性等の材料特性と耐食性を備えた
製品が得られた。特に、吸収エネルギーは、本発明の熱
処理がＤＱＴ法であるにもかかわらず、ＲＱＴ法で熱処
理された比較例の試験Ｎｏ．１４〜１８と同程度の値が
得られており、ＲＱＴ法に匹敵する靱性が得られること
が確認された。また、鋼塊から採取した試験片について
の１０００℃における引張り試験の断面収縮率が７７％
以上と高いこと、熱間圧延後の圧延板の耳割れがほとん
ど認められないことから、供試材の熱間加工性も良好と
いう結果が得られた。As is clear from Table 2, Test No. 3 in which the chemical composition of the test material, the conditions of the hot rolling and the conditions of the heat treatment were within the scope of the present invention. In Examples 1 to 6, the proof stress, tensile strength, absorbed energy and pitting potential were all high, and products having sufficient strength, material properties such as toughness, and corrosion resistance were obtained. In particular, the absorbed energy was the same as in Test No. of the comparative example heat-treated by the RQT method, even though the heat treatment of the present invention was the DQT method. The same value as 14 to 18 was obtained, and it was confirmed that toughness comparable to the RQT method was obtained. In addition, the cross-sectional shrinkage of a test piece taken from a steel ingot in a tensile test at 1000 ° C. was 77%.
From the above, it was high, and almost no edge cracks were observed in the rolled sheet after hot rolling, so that the result that the hot workability of the test material was good was obtained.
【００５２】一方、試験Ｎｏ．７〜１８の比較例は、製
品の強度、靱性、耐食性あるいは熱間加工性の少なくと
も１つの特性が、本発明例に比べて劣っていた。Ｂ含有
率が本発明の範囲より低い試験Ｎｏ．７、８は、吸収エ
ネルギーが低く靱性に劣る他、耳割れも発生しており熱
間加工性も悪い。Ｂ含有率が高すぎる試験Ｎｏ．１０
は、靱性および熱間加工性が悪い。On the other hand, Test No. Comparative Examples 7 to 18 were inferior to at least one property of the product in strength, toughness, corrosion resistance or hot workability as compared with the inventive examples. Test No. B having a B content lower than the range of the present invention. Nos. 7 and 8 have low absorbed energy and poor toughness, and also have cracks in the ears and poor hot workability. Test No. B content was too high. 10
Has poor toughness and hot workability.
【００５３】また、Ｃ含有率が高すぎる試験Ｎｏ．９に
ついては、靱性、耐食性、熱間加工性のいずれにも劣っ
ていた。さらに、１０５０℃以下の温度における累積圧
下率が４０％の場合であり、調整圧延開始温度が高すぎ
る試験Ｎｏ．１１および１０００℃以下における累積圧
下率が４０％未満の試験Ｎｏ．１２と１３については、
調整圧延の条件が本発明の範囲外であるために、製品の
強度、靱性等の材料特性が不良であった。ＲＱＴ法によ
って熱処理された試験Ｎｏ．１４〜１８については、試
験Ｎｏ．１〜５の本発明例に比べて、耐力、引張り強度
が１０％程度低い。これは、未再結晶域での加工によっ
て累積された大きな歪みと直接焼入れの組み合わせによ
る本発明の効果が、比較例の場合にはないためである。
このように、加工歪と直接焼入れの組み合わせが、マル
テンサイト系ステンレス鋼の高強度化を図る上で非常に
有効であることが確認された。Also, in Test No. 1 in which the C content was too high. As for No. 9, all were inferior in toughness, corrosion resistance and hot workability. Furthermore, the case where the cumulative rolling reduction at a temperature of 1050 ° C. or less is 40%, and the test rolling test temperature in which the adjusted rolling start temperature is too high Test Nos. For 12 and 13,
Since the conditions of the adjustment rolling were out of the range of the present invention, the material properties such as strength and toughness of the product were poor. Test No. heat-treated by the RQT method Test Nos. 14 to 18 were tested. The yield strength and the tensile strength are about 10% lower than those of the inventive examples 1 to 5. This is because the effect of the present invention by the combination of the large strain accumulated by the processing in the unrecrystallized region and the direct quenching is not in the case of the comparative example.
Thus, it was confirmed that the combination of working strain and direct quenching was very effective in increasing the strength of martensitic stainless steel.
【００５４】以上の実施例から明かなように、本発明の
Ｂを含むマルテンサイト系ステンレス鋼の製造方法によ
れば、熱間加工の際に割れ等の疵を発生させることな
く、強度、靱性、耐食性等の材料特性に優れた製品であ
る鋼材を得ることができる。また、本発明の方法で得ら
れる鋼材は、Ｃ含有率が低いため溶接性にも優れてい
る。As is clear from the above examples, according to the method for producing martensitic stainless steel containing B of the present invention, the strength and toughness can be improved without generating cracks and other flaws during hot working. In addition, it is possible to obtain a steel material which is a product having excellent material properties such as corrosion resistance. Further, the steel material obtained by the method of the present invention has a low C content, and thus has excellent weldability.
【００５５】[0055]
【発明の効果】本発明の製造方法によれば、耳割れ等の
疵を発生させることなく、高強度高耐食性マルテンサイ
ト系ステンレス鋼材を製造することが可能である。ま
た、熱間加工と直接焼入れとの組み合わせによる工程の
簡素化、歩留まりの向上効果も得られるので、生産性の
向上あるいは製造コストの節減にも結び付く。このよう
に、本発明の製造方法がマルテンサイト系ステンレス鋼
材料の商業的な製造に及ぼす効果は、極めて大きい。According to the production method of the present invention, it is possible to produce a high-strength, high-corrosion-resistant martensitic stainless steel material without generating flaws such as ear cracks. In addition, a combination of hot working and direct quenching can simplify the process and improve the yield, which leads to an improvement in productivity or a reduction in manufacturing cost. As described above, the effect of the production method of the present invention on the commercial production of martensitic stainless steel materials is extremely large.
【図１】図１は、熱間加工における保持時間と加工温度
と再結晶の関係に及ぼすＢの影響を示す図である。FIG. 1 is a diagram showing the effect of B on the relationship between holding time, working temperature and recrystallization in hot working.
【図２】図２は、マルテンサイト系ステンレス鋼中のＢ
含有率と孔食電位との関係を示す図である。FIG. 2 shows B in martensitic stainless steel.
It is a figure which shows the relationship between a content rate and pitting potential.
Claims (1)
テンレス鋼を、熱間加工における１０００℃以下での累
積圧下率４０％以上の条件で熱間加工した後、直接焼入
れを行うことを特徴とする高強度高耐食性マルテンサイ
ト系ステンレス鋼材の製造方法。C: 0.04% or less, Si: 1.0% or less, Mn: 1.0% or less, Cr: 11 to 14%, Ni: 4 to 8%, Mo: 0. 5~4%, B: 0.0005~0.005%, Al: 0.003~0.1% Cu: 0~ 0.5%, P: 0.04% or less, S: 0.005% or less , N: 0.04% or less, Ti: 0 to 0.02%, V: 0 to 0.5%, Nb: 0 to 0.5%, the balance being Fe and unavoidable impurities After hot working under a condition of a cumulative rolling reduction of not less than 40% at 1000 ° C. or less in hot working, and then directly quenching the martensitic stainless steel material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28969295A JP3243987B2 (en) | 1995-11-08 | 1995-11-08 | Manufacturing method of high strength and high corrosion resistance martensitic stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28969295A JP3243987B2 (en) | 1995-11-08 | 1995-11-08 | Manufacturing method of high strength and high corrosion resistance martensitic stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09125141A JPH09125141A (en) | 1997-05-13 |
| JP3243987B2 true JP3243987B2 (en) | 2002-01-07 |
Family
ID=17746521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28969295A Expired - Fee Related JP3243987B2 (en) | 1995-11-08 | 1995-11-08 | Manufacturing method of high strength and high corrosion resistance martensitic stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3243987B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3620319B2 (en) * | 1998-12-18 | 2005-02-16 | Ｊｆｅスチール株式会社 | Martensitic stainless steel with excellent corrosion resistance and weldability |
| JP4518645B2 (en) * | 2000-01-21 | 2010-08-04 | 日新製鋼株式会社 | High strength and high toughness martensitic stainless steel sheet |
| IT1317649B1 (en) * | 2000-05-19 | 2003-07-15 | Dalmine Spa | MARTENSITIC STAINLESS STEEL AND PIPES WITHOUT WELDING WITH IT PRODUCTS |
| BR102014005015A8 (en) * | 2014-02-28 | 2017-12-26 | Villares Metals S/A | martensitic-ferritic stainless steel, manufactured product, process for producing forged or rolled bars or parts of martensitic-ferritic stainless steel and process for producing all seamless martensitic-ferritic stainless steel |
-
1995
- 1995-11-08 JP JP28969295A patent/JP3243987B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09125141A (en) | 1997-05-13 |
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