JP6610352B2 - Low temperature nickel-containing steel sheet with excellent tensile strength and toughness and method for producing the same - Google Patents

Description

  The present invention relates to a low-temperature nickel-containing steel sheet excellent in tensile strength and toughness and a method for producing the same.

  Steel plates produced by this method can be used for general welding structures such as shipbuilding, bridges, buildings, marine structures, pressure vessels, tanks, line pipes, etc., especially at low temperatures of about -90 ° C to -140 ° C. It is effective in use in a low temperature tank that requires fracture toughness and tensile strength of 540 MPa to 610 MPa.

  With the expansion of the shale gas market, the amount of ethane, which is an associated gas, and the amount of ethylene used as an industrial raw material are increasing. As a material for a tank mounted on an ethane / ethylene ship, a so-called 3.5% Ni steel sheet, which is a kind of nickel-containing steel sheet, is a candidate. However, since the 3.5% Ni steel sheet shows a decrease in toughness due to strain aging, overcoming this is the key to practical use. In order to maintain excellent toughness by strain aging, it is necessary that the Charpy impact absorption energy at −90 to −140 ° C. is 150 J or more at the time of the base material. At present, it is difficult to stably achieve 150 J or more, and improvement is necessary.

Inclusions may be involved in the low value generated at a certain frequency in the Charpy impact absorption energy at −90 to −140 ° C. of the ferritic low-temperature nickel-containing steel sheet. In steel slabs manufactured by continuous casting, inclusions of several μm remain without being floated and separated, but if the cleanliness is normal, such independent inclusions are −90 to −140 ° C. The impact on Charpy impact absorption energy is small. However, when a cluster in which inclusions of several μm aggregate and coalesce is formed, the Charpy impact absorption energy at −90 to −140 ° C. may decrease to less than 150 J. The main inclusion is alumina (Al ₂ O ₃ ).

  Cross rolling is a method for reducing the harm caused by inclusions such as extension inclusions such as MnS. Cross rolling is a hot rolling that creates the shape of a steel sheet. Of the rolling that is usually performed only in the longitudinal direction of the steel sheet, a part of the rolling is performed in the width direction of the steel sheet, and the inclusions are MnS. In this case, since the elongation of MnS in the longitudinal direction of the steel sheet is suppressed, the Charpy impact absorption energy is improved in the Charpy test using a test piece in which the longitudinal direction of the test piece is parallel to the rolling width direction.

  For example, in Patent Literature 1 and Patent Literature 2, bending workability and low-temperature toughness are improved by performing width direction rolling when performing cross rolling in a non-recrystallization temperature range. However, when the width direction rolling is performed in the non-recrystallization temperature region, the non-recrystallization region rolling is performed while the austenite grain size before the reduction is large, and on the contrary, the toughness often decreases. The goal cannot be achieved.

  Moreover, in patent document 3, it is set as the steel plate with high isotropic by prescribing | regulating the reduction ratio of the width direction rolling at the time of implementing cross rolling, and a longitudinal direction rolling. Although this method is effective for the control of inclusions, this method achieves the above-mentioned purpose because the effective crystal grain size, which is the factor that most affects the Charpy impact absorption energy, cannot be reduced only by specifying the reduction ratio. Can not.

  In the LNG tank, high strength is required in addition to the low temperature toughness. In order to build a large tank, a tensile strength of 540 MPa or more is required in terms of tensile strength, while a tensile strength of 610 MPa or less is required due to weldability restrictions. That is, the current technology cannot provide a nickel-containing steel sheet for low temperature that is excellent in tensile strength and toughness.

Japanese Patent No. 4897125 JP 2005-226080 A JP 2002-161341 A

  The problem to be solved by the present invention is to provide a low-temperature nickel-containing steel sheet excellent in tensile strength and toughness and a method for producing the same.

  The present invention provides a nickel steel for low temperature excellent in toughness and a method for producing the same, and the gist thereof is as follows.

(1) Steel components are in mass%, C: 0.03% or more and 0.10% or less, Si: 0.02% or more and 0.40% or less, Mn: 0.30% or more and 1. 20% or less, Ni: 3.0% or more and less than 5.0%, Al: 0.010% or more and 0.080% or less,
T-O: 0.0001% or more and 0.0030% or less, P: 0.0010% or more and 0.0100% or less, S: 0.0001% or more and 0.0035% or less, N: 0.0005 % And 0.0070% or less, the balance is Fe and inevitable impurities, the alumina cluster index is 0.030 or less, the effective crystal grain size is 12.0 μm or less, and the average value of tensile strength Is a nickel-containing steel sheet for low temperature excellent in tensile strength and toughness, characterized in that the Charpy impact absorption energy at −140 ° C. is 540 MPa or more and 610 MPa or less and 150 J or more.

(2) Further, Cr: 0.05% to 2.0%, Mo: 0.02% to 1.0%, Cu: 0.1% to 3.0%, Nb: 0 0.005% to 0.100%, V: 0.010% to 0.500%, Ti: 0.005% to 0.500%, Ca: 0.0001% to 0.0050%,
Mg: 0.0001% to 0.0050%, REM: 0.0001% to 0.0100%, Zr: 0.0001% to 0.0100%, B: 0.0002% to 0.0030% The low-temperature nickel-containing steel sheet having excellent tensile strength and toughness according to (1) above, containing one or more of the following:

(3) Steel is mass%, C: 0.03% or more and 0.10% or less, Si: 0.02% or more and 0.40% or less, Mn: 0.30% or more and 1.20% Ni: 3.0% or more and less than 5.0%, Al: 0.010% or more and 0.080% or less, TO: 0.0001% or more and 0.0030% or less, P : 0.0010% to 0.0100%, S: 0.0001% to 0.0035%, N: 0.0005% to 0.0070%, with the balance being Fe and inevitable impurities After the slab is heated to 900 ° C. or more and 1270 ° C. or less, hot rolling is performed, the total rolling reduction ratio of the hot rolling is 0.65 or more, and the rolling reduction ratio of the cross rolling performed in the rolling width direction of the hot rolling is 0.1 to 0.6, and the temperature range of cross rolling is 800 ° C. or more and 100 The average temperature of the tensile strength is tempered by cooling the steel sheet to 500 ° C. or more and 680 ° C. or less immediately after the rolling. A method for producing a nickel-containing steel sheet for low temperature excellent in tensile strength and toughness, characterized in that a steel sheet having a value of 540 MPa or more and 610 MPa or less and a Charpy impact absorption energy at -140 ° C of 150 J or more is obtained.

(4) Further, Cr: 0.05% to 2.0%, Mo: 0.02% to 1.0%, Cu: 0.1% to 3.0%, Nb: 0 0.005% to 0.100%, V: 0.010% to 0.500%, Ti: 0.005% to 0.500%, Ca: 0.0001% to 0.0050%,
Mg: 0.0001% to 0.0050%, REM: 0.0001% to 0.0100%, Zr: 0.0001% to 0.0100%, B: 0.0002% to 0.0030% The manufacturing method of the nickel containing steel plate for low temperature excellent in the tensile strength and toughness as described in (3) characterized by containing the following 1 type (s) or 2 or more types.

  According to the present invention, it is possible to provide a low-temperature nickel-containing steel sheet excellent in tensile strength and toughness and a method for producing the same, and it can be said that the invention has high industrial value.

It is a graph which shows the relationship between an alumina cluster index and cross rolling reduction. It is a graph which shows the relationship between Charpy impact absorption energy and an alumina cluster index. It is a graph which shows the relationship between an effective crystal grain size and cross rolling temperature. It is a graph which shows the relationship between an effective crystal grain diameter and a total reduction. It is a graph which shows the relationship between toughness and an effective crystal grain size.

  The present invention will be described in detail. The inventors of the present invention have disclosed that alumina clusters having a Ni content of 3.0% or more and less than 5.0% among nickel-containing steel sheets for low temperature use, that is, alumina clusters, that is, alumina whose major axis is several μm, are continuously in the rolling direction. In order to clarify the influence of aggregates distributed in the area, the fracture surface of the Charpy impact test specimen was investigated. As a result, when the longitudinal direction of the Charpy test piece is parallel to the width direction of the steel sheet, the continuous distribution in the rolling direction of the alumina cluster is parallel to the surface that becomes the fracture surface of the Charpy test piece. It has been newly found that a separation-like coarse void coalescence fracture surface is formed, and the Charpy impact absorption energy is reduced through a decrease in ductile crack growth resistance and a transition from ductile crack growth to brittle fracture. The inventors conceived that reducing the number of alumina on the surface parallel to the fracture surface of the Charpy test piece, that is, the surface perpendicular to the width direction of the steel sheet is effective in improving toughness, and studied various methods. As a result, it has been found that it is necessary to strictly define various conditions when carrying out cross rolling in which a part of rough rolling is reduced in the width direction of the steel sheet during hot rolling of the steel sheet. This will be described in detail below.

The effect of cross rolling, in which a part of the rough rolling was reduced in the width direction of the steel sheet, was confirmed by experiments. Here, cross rolling refers to rolling performed in a direction substantially perpendicular to the final longitudinal direction of the steel sheet, and is performed during rough rolling. After cross rolling, the steel slab is rotated about 90 ° in order to perform rolling in the longitudinal direction of the steel plate. By performing cross rolling, dense alumina is distributed in the width direction of the steel sheet, and the number of alumina on the plane perpendicular to the width direction of the steel sheet, that is, the plane parallel to the fracture surface of the Charpy specimen Decreases relatively. The distribution of alumina clusters was measured from information on the fracture surface of a Charpy specimen approximately parallel to the plane perpendicular to the width direction of the steel plate. A SEM (scanning electron microscope) secondary electron beam image, a fracture surface photograph of a Charpy impact test piece was taken at a magnification of 10 times, and the total length of separation-like vertical crack fracture surfaces (unit: mm) was measured. A value obtained by dividing this by the fracture surface area (80 mm ² ) was defined as the alumina cluster index. The unit is 1 / mm. FIG. 1 shows the relationship between the alumina cluster index and the cross rolling reduction ratio. The cross rolling reduction ratio is a value obtained by dividing the total reduction amount in the cross rolling by the total reduction amount in the hot rolling. As the rolling reduction ratio increases, the alumina cluster index tends to decrease.

  The relationship between the Charpy impact absorption energy and the alumina cluster index is shown in FIG. As the alumina cluster index decreases, Charpy impact absorption energy increases. In order to improve toughness, that is, to make vE-140 150J, the alumina cluster index needs to be 0.030 or less, and for this, the rolling reduction of cross rolling needs to be 0.1 or more. When the rolling reduction ratio of the cross rolling exceeds 0.6, the upper limit of the rolling reduction ratio of the cross rolling is set to 0.6 for the operational reason that the width of the steel sheet becomes large and subsequent hot rolling becomes difficult.

  In order to obtain a steel sheet with excellent toughness, it is necessary to reduce the effective crystal grain size in addition to simply ensuring the reduction ratio that defines the cross rolling reduction ratio as described above. For this purpose, it is necessary to define the temperature at which cross rolling is carried out and to define the total rolling reduction ratio of hot rolling. This will be described in detail below.

  Defining the temperature range of cross rolling is important for making the effective crystal grain size fine. When the cross rolling temperature is higher than 1000 ° C., austenite becomes coarse due to grain growth after recrystallization, and the effective crystal grain size of the structure mainly composed of bainite after transformation becomes coarse. On the contrary, even when the cross rolling temperature is less than 800 ° C., the effective crystal grain size becomes coarse because rolling mainly in the non-recrystallization temperature region where recrystallization hardly occurs. The relationship between the effective crystal grain size and the cross rolling temperature is shown in FIG. Here, the effective crystal grain size refers to an average crystal grain size calculated by performing EBSD on the transformed structure and defining an orientation difference of 15 ° or more as a grain boundary.

  Defining the total rolling reduction of hot rolling is also important for reducing the effective crystal grain size. Increasing the total rolling reduction in hot rolling reduces the effective crystal grain size. This is because the microstructure mainly composed of bainite after transformation is refined by refining austenite through recrystallization and further introducing dislocations into austenite through reduction in an unrecrystallized region. FIG. 4 shows the relationship between the effective crystal grain size, the total rolling reduction, and the toughness when the cross rolling temperature is 800 ° C. or higher and 1000 ° C. or lower. By setting the total rolling reduction to 0.65 or more, the effective crystal grain size can be reduced to 12.0 μm or less. Here, the total reduction ratio is a value obtained by dividing a value obtained by subtracting the steel plate thickness after hot rolling from the steel slab thickness before hot rolling by the steel slab thickness before hot rolling. Note that the hot rolling in the present invention is a cross rolling in which part of the hot rolling is performed in a direction substantially perpendicular to the final steel plate longitudinal direction, and the remaining part is performed in a direction substantially parallel to the final steel plate longitudinal direction. The total rolling reduction is the value obtained by dividing the total rolling reduction of cross rolling and straight rolling by the thickness of the steel slab before hot rolling, and the cross rolling rolling reduction is the rolling reduction of cross rolling. It is the value divided by the thickness of the steel piece before hot rolling.

  FIG. 5 shows the relationship between toughness and effective crystal grain size when the effective crystal grain size is refined by defining the temperature range of cross rolling and the total rolling reduction of hot rolling. In order to ensure toughness, that is, to make vE-140 150J or more, the effective crystal grain size needs to be 12.0 μm or less. For this purpose, the cross rolling temperature is 800 ° C. or more and 1000 ° C. or less, and the total rolling reduction is Needs to be 0.65 or more.

The range of alloy elements of the steel sheet is specified below.
Since C is an essential element for securing a tensile strength of 540 MPa or more, its addition amount is set to 0.03% or more. However, on the other hand, when the amount of C is increased, the toughness is lowered and it becomes difficult to secure 150 J or more with the Charpy impact absorption energy at −140 ° C., and the tensile strength exceeds 610 MPa. %.

  Since Si is an essential element for securing a tensile strength of 540 MPa or more, its addition amount is set to 0.02% or more. On the other hand, however, Si addition exceeding 0.40% makes it difficult to secure 150 J or more with a Charpy impact absorption energy of −140 ° C. due to a decrease in toughness, and the tensile strength exceeds 610 MPa. 40%.

  Mn is an element effective for securing a tensile strength of 540 MPa or more, and at least 0.30% or more is necessary, but conversely, if added over 1.20%, it is susceptible to temper embrittlement. Becomes higher, the toughness decreases, and it becomes difficult to secure 150 J or more with the Charpy impact absorption energy at −140 ° C., and the tensile strength exceeds 610 MPa. Therefore, the amount of Mn added is defined as 0.30% or more and 1.20% or less.

  As for Ni, toughness is ensured at the lower limit, that is, to ensure 150 J or more with a Charpy impact absorption energy of −140 ° C., addition of 3.0% or more is required at least. Although the upper limit is not particularly specified, if it is 5.0% or more, the production cost is greatly increased, and therefore less than 5.0% is preferable. Therefore, the addition amount of Ni is set to 3.0% or more and less than 5.0%.

  Al is an element effective for deoxidation, and at least 0.010% or more must be added. If the addition is less than 0.010% or more than 0.080%, the toughness decreases due to the increase in the volume fraction of inclusions, and it is difficult to secure 150 J or more with the Charpy impact absorption energy at −140 ° C. Become. Therefore, the addition amount of Al is defined as 0.010% or more and 0.080% or less.

  The lower limit of T-O is not particularly specified, but if it is less than 0.0001%, productivity decreases due to an increase in the refining load, so 0.0001% or more is preferable. If added over 0.0030%, the toughness is lowered through the formation of alumina clusters, and it becomes difficult to secure 150 J or more with the Charpy impact absorption energy at -140 ° C, so the upper limit is made 0.0030%. Therefore, the addition amount of T-O is set to be 0.0001% to 0.0030%.

  Although there is no particular limitation on the lower limit of P, 0.0010% or more is preferable because the productivity is greatly reduced due to an increase in the refining load. On the other hand, if it exceeds 0.0100%, the toughness decreases due to temper embrittlement, and it becomes difficult to ensure 150 J or more with Charpy impact absorption energy at -140 ° C, so the upper limit is made 0.0100%. Therefore, the addition amount of P is set to 0.0010% or more and 0.0100% or less.

  The lower limit of S is not particularly specified, but if it is less than 0.0001%, productivity is significantly reduced due to an increase in the refining load, so 0.0001% or more is preferable. On the other hand, if it exceeds 0.0035%, the toughness decreases and it becomes difficult to ensure 150 J or more with the Charpy impact absorption energy at -140 ° C, so the upper limit is made 0.0035%. Therefore, the addition amount of S is set to 0.0001% or more and 0.0035% or less.

  N is not particularly limited as to the lower limit, but if it is less than 0.0005%, the productivity is reduced by an increase in the refining load, so 0.0005% or more is preferable. In addition, if it exceeds 0.0070%, the toughness is lowered and it is difficult to ensure 150 J or more with the Charpy impact absorption energy at -140 ° C, so the upper limit is made 0.0070%. Therefore, the addition amount of N is set to 0.0005% or more and 0.0070% or less.

In the present invention, the following elements can be further added.
Cr is an element effective for ensuring hardenability, and at least 0.01% of addition is necessary, but if added over 1.0%, toughness and weldability deteriorate. Therefore, the addition amount of Cr is defined as 0.01% or more and 1.0% or less.

  Mo is an element effective in reducing temper embrittlement, and at least 0.01% of addition is required. Conversely, if added over 0.5%, toughness and weldability are reduced. Therefore, the addition amount of Mo is defined as 0.01% or more and 0.5% or less.

  In order to ensure strength, Cu needs to be added at least 0.1% or more, but if it exceeds 3.0%, the toughness decreases. Therefore, the addition amount of Cu is defined as 0.1% or more and 3.0% or less.

  Nb is an element effective for securing strength. If the addition is less than 0.005%, the effect is small, and if it exceeds 0.100%, the toughness is lowered. Therefore, the amount of Nb added is defined as 0.005% or more and 0.100% or less.

  V is an element effective for ensuring the strength. If the addition is less than 0.010%, the effect is small, and if it exceeds 0.500%, the toughness is lowered. Therefore, the addition amount of V is defined as 0.010% or more and 0.500% or less.

  Ti is an element effective for securing strength. If the addition is less than 0.005%, the effect is small, and if it exceeds 0.500%, the toughness is lowered. Therefore, the addition amount of Ti is defined as 0.005% or more and 0.500% or less.

  Ca is an element effective for preventing nozzle clogging. If the addition is less than 0.0001%, the effect is small, and if the addition exceeds 0.0050%, the toughness is reduced. Therefore, the addition amount of Ca is defined as 0.0001% or more and 0.0050% or less.

  Mg is an element effective for improving toughness. If the addition is less than 0.0001%, the effect is small, and if the addition exceeds 0.0050%, the toughness is reduced. Therefore, the addition amount of Mg is defined as 0.0001% or more and 0.0050% or less.

  REM is an element effective for improving toughness. If the addition is less than 0.0001%, the effect is small, and if the addition exceeds 0.0100%, the toughness is reduced. Therefore, the amount of REM added is specified to be 0.0001% or more and 0.0100% or less.

  Zr is an element effective for improving toughness. If the addition is less than 0.0001%, the effect is small, and if the addition exceeds 0.0100%, the toughness is reduced. Therefore, the addition amount of Zr is defined as 0.0001% or more and 0.0100% or less.

  B is an element effective for improving hardenability. If it is less than 0.0002%, the effect is small, and if it exceeds 0.0030%, the toughness decreases. Therefore, the addition amount of B is defined as 0.0002% or more and 0.0030% or less.

  In manufacturing steel sheets and welding materials, Zn, Sn, Sb, etc., which can be mixed as raw materials including additive alloys or unavoidable impurities eluted from furnace materials during melting, are less than 0.002%. If it is mixed, the effect of the present invention is not impaired.

  Next, the manufacturing method of the steel plate of this invention is described. The steel sheet is manufactured by the method of hot rolling a slab manufactured by continuous casting by the above method, but in addition to the above, the following conditions are generally implemented to refine the structure mainly composed of bainite. Is also required. When the heating temperature of the steel slab is 1270 ° C. or higher, the structure mainly composed of martensite after transformation is coarsened by the growth of austenite grains, and the toughness is reduced. The Charpy impact absorption energy at −140 ° C. is 150 J or higher. It becomes difficult to ensure, and if it is less than 900 ° C, hot rolling becomes difficult, so the temperature is set to 900 ° C or more and 1270 ° C or less. The temperature before the final pass in the rolling performed after the cross-rolling is over 850 ° C., the unrecrystallization zone pressure decreases, the structure mainly composed of martensite after transformation is coarsened, and the temperature before 600 ° C. is hot Since rolling becomes difficult, the temperature before the final pass is set to 600 ° C. or higher and 850 ° C. or lower.

Immediately after rolling, it is cooled with water and further tempered. If the tempering temperature is less than 500 ° C., temper embrittlement occurs, and if it exceeds 680 ° C., the toughness decreases due to the formation of fresh martensite, and it becomes difficult to ensure 150 J or more with Charpy impact absorption energy at −140 ° C. The heating temperature at the time of tempering is set to 500 ° C. or more and 680 ° C. or less.
By the heat treatment, bainite tempered to an optimum temperature can be mainly used, and toughness is improved.

  Tensile tests and Charpy impact tests were carried out on steel plates with thicknesses of 15 and 40 mm manufactured under various chemical components and manufacturing conditions. The evaluation results of the chemical composition, alumina cluster index, effective crystal grain size, plate thickness, hot rolling conditions, heat treatment conditions, and mechanical properties of the steel sheet are shown in Table 1-1 and Table 1-2 (Table 1-1 continued). . The tensile test was performed based on the metal material tensile test method described in JIS Z 2241. The test piece was sampled so that the longitudinal direction of the test piece was perpendicular to the rolling direction at a site that entered the steel plate surface by ¼ of the plate thickness. Two tests were performed at room temperature, and an average value of tensile strength of 540 MPa or more and 610 MPa or less was regarded as acceptable. In the Charpy impact test, a full-size test piece of 2 mm V notch test piece was placed at a position where 1/4 of the plate thickness entered from the surface of the steel plate so that the longitudinal direction of the test piece was perpendicular to the rolling direction. The line connecting the leading edges of the samples was taken so as to be parallel to the thickness direction. Three tests were conducted at a test temperature of −140 ° C., and the average value of the three samples was determined to be 150 J or more. As shown in Examples 1 to 30, a steel sheet having excellent tensile strength and toughness was obtained by manufacturing a steel sheet using the components and manufacturing method defined in the present invention.

  From the above examples, it is clear that the steel plates of Examples 1 to 30 manufactured according to the present invention are steel plates excellent in tensile strength and toughness.

Claims (4)

Steel component is mass%,
C: 0.03% or more and 0.10% or less,
Si: 0.02% or more and 0.40% or less,
Mn: 0.30% or more and 1.20% or less,
Ni: 3.0% or more and less than 5.0%,
Al: 0.010% or more and 0.080% or less,
T-O: 0.0001% or more and 0.0030% or less,
P: 0.0010% or more and 0.0100% or less,
S: 0.0001% to 0.0035%,
N: 0.0005% or more and 0.0070% or less, the balance being Fe and inevitable impurities, alumina cluster index is 0.030 or less, effective crystal grain size is 12.0 μm or less, tensile A nickel-containing steel sheet for low temperature excellent in tensile strength and toughness, characterized by having an average strength of 540 MPa or more and 610 MPa or less and a Charpy impact absorption energy at -140 ° C of 150 J or more. further,
Cr: 0.05% or more and 2.0% or less,
Mo: 0.02% or more and 1.0% or less,
Cu: 0.1% or more and 3.0% or less,
Nb: 0.005% or more and 0.100% or less,
V: 0.010% to 0.500%,
Ti: 0.005% or more and 0.500% or less,
Ca: 0.0001% to 0.0050%,
Mg: 0.0001% or more and 0.0050% or less,
REM: 0.0001% or more and 0.0100% or less,
Zr: 0.0001% or more and 0.0100% or less,
B: One type or two or more types of 0.0002% or more and 0.0030% or less are contained, The nickel-containing steel sheet for low temperature excellent in tensile strength and toughness according to claim 1. Steel is mass%
C: 0.03% or more and 0.10% or less,
Si: 0.02% or more and 0.40% or less,
Mn: 0.30% or more and 1.20% or less,
Ni: 3.0% or more and less than 5.0%,
Al: 0.010% or more and 0.080% or less,
T-O: 0.0001% or more and 0.0030% or less,
P: 0.0010% or more and 0.0100% or less,
S: 0.0001% to 0.0035%,
N: 0.0005% or more and 0.0070% or less, and the remaining slab composed of Fe and inevitable impurities is heated to 900 ° C. or more and 1270 ° C. or less, and then hot-rolled. The total rolling reduction is 0.65 or more, the rolling reduction of the cross rolling performed in the rolling width direction in the hot rolling is 0.1 to 0.6, the temperature range of the cross rolling is 800 ° C. or more and 1000 ° C. or less, and the finish is 1 pass. The pre-temperature is 600 ° C. or more and 850 ° C. or less, water cooling is performed immediately after rolling, the steel sheet is further heated to 500 ° C. or more and 680 ° C. or less and then tempering is performed, and the average value of tensile strength is 540 MPa or more and 610 MPa or less. And a method for producing a low temperature nickel-containing steel sheet having excellent tensile strength and toughness, characterized by obtaining a steel sheet having Charpy impact absorption energy at 150 ° C. or higher at −140 ° C. . further,
Cr: 0.05% or more and 2.0% or less,
Mo: 0.02% or more and 1.0% or less,
Cu: 0.1% or more and 3.0% or less,
Nb: 0.005% or more and 0.100% or less,
V: 0.010% to 0.500%,
Ti: 0.005% or more and 0.500% or less,
Ca: 0.0001% to 0.0050%,
Mg: 0.0001% or more and 0.0050% or less,
REM: 0.0001% or more and 0.0100% or less,
Zr: 0.0001% or more and 0.0100% or less,
B: One or two or more types of 0.0002% or more and 0.0030% or less are contained, The manufacturing method of the nickel containing steel plate for low temperature excellent in the tensile strength and toughness of Claim 3 characterized by the above-mentioned.