EP0484960B1 - Kaltgewalztes Stahlband mit hervorragender Pressverformbarkeit und Verfahren zur Herstellung - Google Patents

Kaltgewalztes Stahlband mit hervorragender Pressverformbarkeit und Verfahren zur Herstellung Download PDF

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Publication number
EP0484960B1
EP0484960B1 EP91119058A EP91119058A EP0484960B1 EP 0484960 B1 EP0484960 B1 EP 0484960B1 EP 91119058 A EP91119058 A EP 91119058A EP 91119058 A EP91119058 A EP 91119058A EP 0484960 B1 EP0484960 B1 EP 0484960B1
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Prior art keywords
steel strip
less
cold
rolled steel
press formability
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EP91119058A
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English (en)
French (fr)
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EP0484960B9 (de
EP0484960B2 (de
EP0484960A2 (de
EP0484960A3 (en
Inventor
Teruaki c/o Hirohata Seitetsusho Yamada
Masahiko c/o Hirohata Seitetsusho Oda
Yuzo c/o Hirohata Seitetsusho Nishimoto
Hiroshi c/o Hirohata Seitetsusho Kubo
Michihiro c/o Hirohata Seitetsusho Nouno
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Nippon Steel Corp
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Nippon Steel Corp
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Priority claimed from JP2302697A external-priority patent/JPH0762209B2/ja
Priority claimed from JP2321054A external-priority patent/JPH0747796B2/ja
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0426—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0436—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0473—Final recrystallisation annealing

Definitions

  • This invention relates to a cold-rolled steel strip having excellent combined press-formability and also to a method of producing such a steel strip by continuous annealing.
  • Japanese Patent Unexamined Publication No. 63-210243 discloses a method in which a cold-rolled steel strip of superformability having a total elongation of not less than 54% and r ⁇ value of not less than 2.0 is subjected to box-annealing having stepped heating.
  • Japanese Patent Unexamined Publication No. 61-276930 discloses a method in which a very low carbon-steel having Nb and Ti added thereto is cooled at a rate of 10°C/sec. within 0.5 seconds after the hot-rolling of the steel, thereby producing the cold-rolled very low carbon-steel strip having excellent elongation and deep-drawability.
  • Japanese Patent Unexamined Publication Nos. 61-113724 and 63-76848 disclose methods of producing a steel strip having extremely high r ⁇ value, r45 and El.
  • Another object of the invention is to provide a method of producing such a cold-rolled steel strip by continuous annealing.
  • the inventors of the present invention have made an extensive study in an effort to develop a cold-rolled steel strip which exhibits excellent press formability (hereinafter referred to as “combined press formability") in an actual pressing for forming products or parts (hereinafter referred to as “combined pressed product”) of a complicated shape, such as a wheel house inner, having a deep-drawn portion, a stretched portion and a draw bead.
  • the present inventors also have studied a method of producing such a steel strip by continuous annealing. As a result, the present inventors have found the following results.
  • the inventors of the present invention studied the relation between the combined pressed formability and the characteristic values of the steel materials in further detail, and it has been found that the steel strip can have excellent combined press formability (1) if the steel strip has T.S45 of 28.5 to 31.0 kgf/mm and r45 of not less than 1.90 and (2) if the content of B is not more than 0.0004% and preferably not more than 0.0002%. Further, it has been found that (3) if the steel strip is adjusted to have a surface roughness Ra of 0.2 to 1.0 ⁇ m, more excellent combined pressed formability can be obtained.
  • the above cold-rolled steel strip (as reported in Lecture Report of Japan Steel Association, Vol. 3, No. 6, 1990, p.
  • Fig. 1 is a graph showing the relation between these combined press formabilities and the characteristic values of the materials in detail, and it will be appreciated that the steel strip can exhibit excellent combined press formability (1) if the steel strip has T.S45 of 28.5 to 31.0 kgf/mm and r45 of not less than 1.90 and (2) if the content of B is not more than 0.0004% and preferably not more than 0.0002%.
  • Fig. 2 is a graph showing the results of examination of the combined press formability in the actual pressing with respect to steel strips which had T.S45 of 29.5 kgf/mm, r45 of 2.14 and the B content of not more than 0.0002%, and were adjusted by skinpass rolling of 0.8% into a surface roughness Ra of 0.2 to 1.0 ⁇ m. From Fig.
  • the steel strip of the present invention adjusted to a surface roughness Ra of 0.2 to 0.1 ⁇ m exhibits more excellent combined press formability and, that the steel strip of the present invention exhibits excellent combined press formability in the actual pressing for forming a pressed product of a complicated shape, such for example as a wheel house inner, having a deep-drawn portion, a stretched portion and a draw bead, thus providing an excellent industrial value.
  • a surface treated steel strip such as an electrically Zn-plated steel strip
  • this surface treated steel strip can also exhibit excellent combined press formability, thus providing the advantages of the present invention.
  • the cold-rolled steel strip consists, by weight, of not more than 0.0025% C, not more than 0.05% Si, not more than 0.30% Mn, not less than 0.007% but not more than 0.030% P, not more than 0.020% S, not more than 0.080% sol Al, not more than 0.0030% N, not less than 0.025% but not more than 0.120% Ti, not less than 0.003% but not more than 0.020% Nb, not more than 0.0004% B, and the balance Fe and incidental impurities, these are the basic components for obtaining the cold-rolled steel strip having excellent combined press formability, satisfying the above characteristics, on an economical industrial basis.
  • the invention described in the above subject matters (2) and (4) is directed to a method of producing the cold-rolled steel strip, described in the above subject matters (1) and (3), by continuous annealing.
  • the features of the invention described in the above subject matters (2) and (4) are:
  • the C is a very important element for obtaining the cold-rolled steel strip, having r45 of not less than 1.90, by continuous annealing, and if the C content exceeds 0.0025%, this characteristic value can not be obtained. Therefore, the upper limit of the C content should be not more than 0.0025%.
  • Sol Al is usually used as an deoxidizer. However, in the steel of the present invention, it is not undesirable at all to effect Ti deoxidation, and therefore there is no need to specify the lower limit of sol Al. r45 decreases with the increase of the content of sol Al, so that the characteristic value of not less than 1.90 is hardly obtained. Therefore, this content is limited to not more than 0.080%.
  • Ti is a very important element for obtaining the r45 value of not less than 1.90, and if the Ti content is less than 0.025%, this characteristic value can not be obtained. Also, if the Ti content exceeds 0.120%, T.S45 exceeds 31.0 kgf/mm. Therefore, the Ti content is limited to 0.025% to 0.120%.
  • Nb is a more important element than Ti so as to obtain r45 of not less than 1.90, and if the Nb content is less than 0.003%, this characteristic value can not be obtained. Also, if the Nb content exceeds 0.020%, the recrystallization temperature becomes high, and the crystal grains become finer, so that T.S45 exceeds 31.0 kgf/mm. Therefore, the Nb content is limited to 0.003% to 0.020%.
  • the B is an element which markedly improves the deep drawing-induced brittleness, and at the same time the cold-rolled steel strip containing more than 0.0005% B has a lower value of local elongation at a tensile test as compared with that having the same tensile strength (T.S), as described above, with the result that good combined press formability can not be obtained. Therefore, the B content should be not more than 0.0004% and preferably not more than 0.0002%.
  • the hot rolling with the particular condition serves to combine C with Ti to form TiC to thereby make C harmless, and also serves to make the crystal grains of the hot-rolled strip fine by the combined effects achieved by the addition of not less than 0.025% Ti and not less than 0.003% Nb.
  • the heating condition before the hot rolling is not particularly limited, and may be an ordinary heating condition. However, in order to obtain the softer steel strip, it is preferred to use the heating temperature (hereinafter referred to as "SRT") of not more than 1100°C.
  • SRT heating temperature
  • finishing temperature of the hot rolling is less than 880°C, the crystal grains become coarse, so that the value of r45 is markedly decreased. Also, if this finishing temperature exceeds 940°C, the crystal grains become too coarse, so that r45 of not less than 1.90 can not be obtained. Therefore, the finishing temperature should be 880 to 940°C.
  • the coiling temperature (hereinafter referred to as "C.T”) is a very important factor in promoting the precipitation of TiC and its coarse structure so as to obtain a very excellent r45 value. If this temperature is less than 680°C, the precipitation and coarse structure of TiC are insufficient, so that r45 value is low. If this temperature exceeds 680°C, the precipitation and coarse structure of TiC are promoted, so that the r45 value is improved. If this temperature exceeds 720°C, the coarse precipitation of TiC occurs, so that the excellent r45 value can be obtained. If this temperature exceeds 770°C, the crystal grains become coarse, so that the r45 value of not less than 1.90 can not be obtained.
  • the coiling temperature should be 720 to 770°C.
  • the present method is greatly different from a method as disclosed in Japanese Patent Unexamined Publication No. 61-276930 in which a strip is coiled out at temperatures of not more than 710°C.
  • the crystal grains of the hot-rolled strip fine, it is necessary to cool the strip down to at least 850°C at a rate of not less than 50°C/sec. and within at least 1.5 sec. after the finishing rolling. If the cooling is started later than the above time, or if the temperature range of the cooling, as well as the cooling rate (speed), do not satisfy the above conditions, the crystal grains become large, so that the r45 value of not less than 1.90 can not be obtained.
  • the cold rolling rate should be not less than 70%.
  • the recrystallization annealing is carried out at temperatures of 750 to 900°C, the intended cold-rolled steel strip of the present invention can be obtained, and any other condition does not need to be satisfied. If the annealing temperature is less than 750°C, the r45 value of not less than 1.90 can not be obtained. Also, if the annealing temperature exceeds 900°C, the crystal grains become unduly large, so that T.S45 of 28.5 kgf/mm can not be obtained. Therefore, the annealing temperature is limited to 750 to 900°C.
  • S.P skinpass rolling
  • the steel strip when passing around a hearth roll during the continuous annealing, slips relative to the hearth roll because of a low friction between the steel strip and the hearth roll, and as a result the steel strip travels in a meandering manner in a continuous anealing furance, so that the steel strip may rub or break the wall of the furnace. Therefore, the surface roughness of the steel strip is made coarse during the cold rolling.
  • the upper limit of the S.P amount should be about 1.5% which is equal to the upper limit of the amount of S.P usually applied to ordinary cold-rolled steel strips.
  • the surface roughness of the steel strip can be controlled by determining the surface roughness of the skinpass rolling roll and the rolling rate of the skinpass rolling.
  • the present invention can be applied not only to the method of producing the cold-rolling steel strip but also to a method of producing a base plate (substrate) for an electroplated (e.g. galvanized or tinned) steel strip and a base plate for a surface treated steel strip such for example as one coated with an organic film.
  • Characteristic values of the properties of such a surface treated steel strip are influenced by characteristic values of the properties (e.g. hardness) of metal or alloy plated on the surface of the steel strip and the thickness of the plated film, so that usually Y.P. and T.S become high whereas El and the r value become low.
  • the press formability of the surface-treated steel strip is determined not by the characteristic values of the plated steel strip including the plated film but by the properties of the substrate or base plate (i.e., steel strip per se). Namely, if the characteristic values (the properties and surface roughness) of the base plate of the surface treated steel strip satisfy the conditions of the present invention, excellent combined press formability can be obtained. Therefore, the surface treated steel strip having excellent combined press formability can be produced using the cold-rolled steel strip of the present invention as the base plate.
  • hot-rolled steel strips (thickness: 4 mm) were prepared, and then were cold-rolled into a thickness of 0.8 mm. Then, each of the cold-rolled steel strips was recrystallization annealed at 820°C for 60 seconds by continuous annealing, and then was cooled to room temperature, and then was subjected to skinpass rolling to thereby obtain the cold-rolled steel strip.
  • Steels A, B and E are out of the range of the present invention in terms of the composition, and steels C, D and F are within the range of the present invention.
  • Sample Nos. 3, 4, 5, 6, 8 and 12 were prepared according to the above subject matters (1) and (2) of the present invention, and each of these samples had T.S45 of 28.5 to 31.0 kgf/mm and r45 of not less than 1.90 required for obtaining excellent combined press formability, and their press defective percentage was not more than 0.7%. Thus, these samples exhibited excellent values.
  • sample Nos. 5, 6, 8 and 12 were prepared according to the method of the present invention as described in the above subject matters (3) and (4), and they had a surface roughness Ra of 0.2 to 1.0 ⁇ m, and their press defective percentage was not more than 0.2%, thus exhibiting more excellent results.
  • Sample Nos. 1, 2, 7, 9, 10, 11, 13 and 14 were conventional examples or comparative examples, and each of them could only achieve the press defective percentage of not less than 2.2%.
  • Sample No. 12 is the example of the present invention in which the cold-rolled steel strip of the present invention serving as a base plate was electrically plated with Zn-Ni (plating: 30 g/mm), and the characteristic values represent those of the base plate.
  • Sample No. 1 is the conventional example made of ordinary very low carbon steel containing Ti but no Nb. The obtained characteristic values of this sample were insufficient in T.S45 and r45, and this sample could not be drawn at all, and exhibited the press defective percentage of 100%.
  • Sample No. 2 is the comparative example in which the P content (0.003%) does not fall within the range of the present invention.
  • El45 and r45 mechanical properties
  • the press defective percentage with respect to the actual pressing of the wheel house inner was as poor as 4.2%. From this fact, it will be appreciated that in the actual pressing of the wheel house inner or the like, it is indispensable to obtain T.S45 of 28.5 to 31.0 kgf/mm and r45 of not less than 1.90 as in the steel strip of the present invention.
  • Sample Nos. 3, 4, 5, 6 and 8 are the examples of the present invention in which the composition and the hot rolling condition were varied within the range of the present invention, as shown in Tables 1 and 2. If the production conditions fall within the range of the present invention, the characteristic values necessary for obtaining excellent combined press formability, that is, T.S45 of 28.5 to 31.0 kgf/mm and r45 of not less than 1.90, can be obtained, and the press defective percentage of the steel strip is excellently low, that is, not more than 0.7%. Further, as can be appreciated from Sample Nos. 5, 6 and 8, by limiting the surface roughness Ra of the steel strip to 0.2 to 1.0 ⁇ m, the press defective percentage of the steel strip can be further improved up to not more than 0.2%.
  • Sample No. 7 is the comparative example in which the B content is high (0.0008%), and although the values of T.S45 and r45 of the obtained steel strip fall within the range of the present invention, the press defective percentage is quite poor (3.8%). This is thought to be due to the fact that the value of local elongation at the tensile test of the steel strip was lowered because the B content was as high as 0.0008%. Therefore, it will also be appreciated that it is important to limit the B content to not more than 0.0004%.
  • Sample Nos. 9, 10 and 11 are the comparative examples in which the hot rolling condition is out of the range of the present invention, as shown in Table 2. That is, tQ of sample No. 9, ⁇ of Sample No. 10 and C.T of Sample No. 11 are out of the range of the present invention, and the r45 value of any of these samples is insufficient (that is, less than 1.90), and also the press defective percentage is poor (not less than 2.2).
  • Sample No. 12 is the example of the present invention in which the cold-rolled steel strip of the present invention serving as a base plate was electrically plated with Zn-Ni (plating: 30 g/mm). It will be appreciated that if the characteristic values of the base plate satisfy the required conditions of the steel strip of the present invention, excellent combined press formability can be obtained.
  • Sample No. 13 is the comparative example in which El45 is quite high (55.7%), but T.S45 is low (27.5 kgf/mm) (These characteristic values are similar to those as disclosed in Japanese Patent Unexamined Publication No. 63-76848), and the press defective percentage is poor (4.1%), as shown in Table 2.
  • Sample No. 14 is the comparative example in which C.T is low (620°c) prepared generally according to the method of Japanese Patent Unexamined Publication No. 61-276930, and the r45 value is only 1.83, and the press defective percentage is poor (3.1%), as shown in Table 2.
  • the cold-rolled steel strip according to the above subject matter (1) of the present invention achieves excellent combined press formability.
  • the method as mentioned in the above subject matter (2) of the present invention there can be produced the cold-rolled steel strip having excellent combined pressed formability.
  • the cold-rolled steel strip can exhibit more excellent combined press formability.
  • the cold-rolled steel strip having more excellent combined press formability there can be produced the cold-rolled steel strip having more excellent combined press formability. Therefore, the present invention is of great industrial value.

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
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  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
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  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Claims (4)

  1. Kaltgewalztes Stahlband mit hervorragender kombinierter Preßverformbarkeit, bestehend aus höchstens 0,0025 Gew.-% C, höchstens 0,05 Gew.-% Si, höchstens 0,30 Gew.-% Mn, mindestens 0,007 Gew.-% und höchstens 0,030 Gew.-% P, höchstens 0,020 Gew.-% S, höchstens 0,080 Gew.-% löslichem Al, höchstens 0,0030 Gew.-% N, mindestens 0,025 Gew.-% und höchstens 0,120 Gew.-% Ti, mindestens 0,003 Gew.-% und höchstens 0,020 Gew.-% Nb, höchstens 0,0004 Gew.-% B, wobei der Rest aus Fe und zufälligen Verunreinigungen besteht, wobei das Stahlband eine Zugfestigkeit in 45°-Richtung (ausgedrückt als T.S₄₅)von 28,5 bis 31,0 kp/mm und einen r-Wert in 45°-Richtung (ausgedrückt als r₄₅) von mindestens 1,90 aufweist.
  2. Verfahren zur Herstellung eines kaltgewalzten Stahlbandes mit hervorragender Preßverformbarkeit, mit den folgenden Schritten:
    Bereitstellen einer Stahlbramme, bestehend aus höchstens 0,0025 Gew.-% C, höchstens 0,05 Gew.-% Si, höchstens 0,30 Gew.-% Mn, mindestens 0,007 Gew.-% und höchstens 0,030 Gew.-% P, höchstens 0,020 Gew.-% S, höchstens 0,080 Gew.-% löslichem Al, höchstens 0,0030 Gew.-% N, mindestens 0,025 Gew.-% und höchstens 0,120 Gew.-% Ti, mindestens 0,003 Gew.-% und höchstens 0,020 Gew.-% Nb, höchstens 0,0004 Gew.-% B, wobei der Rest aus Fe und zufälligen Verunreinigungen besteht;
    Erhitzen der Stahlbramme und Warmfertigwalzen bei Endtemperaturen von 880 bis 940°C zum Formen eines Warmbandes;
    anschließender Beginn der Abkühlung des Stahlbandes auf mindestens 850°C innerhalb von 1,5 s nach Beendigung des Warmfertigwalzens, um das Stahlband mit einer Geschwindigkeit von 50 bis 200°C/s abzukühlen, und Aufwickeln des warmgewalzten Stahlbandes bei Temperaturen von 720 bis 770°C;
    anschließendes Kaltwalzen des Stahlbandes mit einem Walzreduktionsgrad von mindestens 70%; und
    anschließendes Rekristallisationsglühen des kaltgewalzten Stahlbandes bei Temperaturen von 750 bis 900°C mittels Durchlaufglühen,
    wobei das kaltgewalzte Stahlband eine Zugfestigkeit in 45°-Richtung (ausgedrückt als T.S₄₅) von 28,5 bis 31,0 kp/mm und einen r-Wert in 45°-Richtung (ausgedrückt als r₄₅) von mindestens 1,90 aufweist.
  3. Kaltgewalztes Stahlband nach Anspruch 1, wobei eine Oberflächenrauhigkeit (Ra) des Stahlbandes längs seiner Mittelachse 0,2 bis 1,0 µm beträgt.
  4. Verfahren nach Anspruch 2, wobei das Stahlband nach dem Rekristallisationsglühen einem Nachwalzen mit einem Walzreduktionsgrad von mindestens 0,3% unterworfen wird, um die Oberflächenrauhigkeit (Ra) des Stahlbandes auf 0,2 bis 1,0 µm zu bringen.
EP91119058A 1990-11-09 1991-11-08 Kaltgewalztes Stahlband mit hervorragender Pressverformbarkeit und Verfahren zur Herstellung Expired - Lifetime EP0484960B9 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP2302697A JPH0762209B2 (ja) 1990-11-09 1990-11-09 複合プレス成形性の優れた冷延鋼板及びその製造方法
JP30269790 1990-11-09
JP302697/90 1990-11-09
JP32105490 1990-11-27
JP321054/90 1990-11-27
JP2321054A JPH0747796B2 (ja) 1990-11-27 1990-11-27 複合プレス成形性の極めて優れた冷延鋼板及びその製造方法

Publications (5)

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EP0484960A2 EP0484960A2 (de) 1992-05-13
EP0484960A3 EP0484960A3 (en) 1993-03-03
EP0484960B1 true EP0484960B1 (de) 1996-03-13
EP0484960B2 EP0484960B2 (de) 2003-05-07
EP0484960B9 EP0484960B9 (de) 2003-10-29

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EP91119058A Expired - Lifetime EP0484960B9 (de) 1990-11-09 1991-11-08 Kaltgewalztes Stahlband mit hervorragender Pressverformbarkeit und Verfahren zur Herstellung

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AT (1) ATE135414T1 (de)
DE (1) DE69117876T3 (de)

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EP0572666B1 (de) * 1991-02-20 1998-05-06 Nippon Steel Corporation Kaltgewalztes stahlblech und galvanisiertes kaltgewalztes stahlblech mit hervorragender formbarkeit und einbrennhärtbarkeit und verfahren zu deren herstellung
JPH06339775A (ja) * 1991-07-15 1994-12-13 Nippon Steel Corp ニッケルおよびニッケル合金材の溶接方法
US5356493A (en) * 1992-07-08 1994-10-18 Nkk Corporation Blister-resistant steel sheet and method for producing thereof
FR2736933B1 (fr) * 1995-07-18 1997-08-22 Lorraine Laminage Procede de fabrication d'une bande de tole mince a emboutissabilite amelioree
FR2742769B1 (fr) * 1995-12-20 1998-01-16 Lorraine Laminage Acier lamine a froid presentant une bonne aptitude au soudage et au brasage
BR112017007273B1 (pt) * 2014-10-09 2021-03-09 Thyssenkrupp Steel Europe Ag produto de aço plano laminado a frio e recozido, recristalizado, e método para a fabricação de um produto de aço plano formado
US11208704B2 (en) 2017-01-06 2021-12-28 Jfe Steel Corporation High-strength cold-rolled steel sheet and method of producing the same
WO2018127984A1 (ja) * 2017-01-06 2018-07-12 Ｊｆｅスチール株式会社 高強度冷延鋼板およびその製造方法

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US4504326A (en) * 1982-10-08 1985-03-12 Nippon Steel Corporation Method for the production of cold rolled steel sheet having super deep drawability
CA1259827A (en) * 1984-07-17 1989-09-26 Mitsumasa Kurosawa Cold-rolled steel sheets and a method of manufacturing the same
US4889566A (en) * 1987-06-18 1989-12-26 Kawasaki Steel Corporation Method for producing cold rolled steel sheets having improved spot weldability
JPH07103422B2 (ja) * 1988-01-14 1995-11-08 新日本製鐵株式会社 良加工性高強度冷延鋼板の製造方法
JPH02194126A (ja) * 1989-01-20 1990-07-31 Sumitomo Metal Ind Ltd 焼付硬化性鋼板の製造方法

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EP0484960B9 (de) 2003-10-29
DE69117876T3 (de) 2003-10-30
ATE135414T1 (de) 1996-03-15
DE69117876T2 (de) 1996-10-31
DE69117876D1 (de) 1996-04-18
EP0484960B2 (de) 2003-05-07
EP0484960A2 (de) 1992-05-13
EP0484960A3 (en) 1993-03-03

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