EP 0572666 B1 19980506 - COLD-ROLLED STEEL SHEET AND GALVANIZED COLD-ROLLED STEEL SHEET WHICH ARE EXCELLENT IN FORMABILITY AND BAKING HARDENABILITY, AND PRODUCTION THEREOF
Title (en)
COLD-ROLLED STEEL SHEET AND GALVANIZED COLD-ROLLED STEEL SHEET WHICH ARE EXCELLENT IN FORMABILITY AND BAKING HARDENABILITY, AND PRODUCTION THEREOF
Title (de)
KALTGEWALZTES STAHLBLECH UND GALVANISIERTES KALTGEWALZTES STAHLBLECH MIT HERVORRAGENDER FORMBARKEIT UND EINBRENNHÄRTBARKEIT UND VERFAHREN ZU DEREN HERSTELLUNG
Title (fr)
TOLE D'ACIER LAMINEE A FROID ET TOLE D'ACIER GALVANISEE PRESENTANT UNE BONNE APTITUDE AU FORMAGE ET A LA TREMPE AU FOUR, ET SA PRODUCTION
Publication
Application
Priority
- JP 9200181 W 19920220
- JP 19603991 A 19910711
- JP 15983191 A 19910605
- JP 4566591 A 19910220
Abstract (en)
[origin: EP0572666A1] A cold-rolled steel sheet, which may be further galvanized if desired, is produced by hot rolling steel containing, on a mass base, 0.0010 to 0.0040 % of C, at most 0.0030 % of N, at most 0.5 % of Si, 0.02 to 1.5 % of Mn, at most 0.08 % of P, at most 0.01 % of S, 0.005 to 0.07 % of acid-soluble Al, at most 0.05 % of Nb (where 0 < Nb % - 93/12 C % </= 0.025 %), 24/14 N % to 72/14N % of Ti, and the balance of Fe and unavoidable impurities at a finish terminating temperature of the Ar3 transformation point or above, rapidly cooling the steel within 2 s after the hot rolling at a cooling rate of 30 DEG C/s to the extend of temperature fall of at least 100 DEG C, winding at 650 to 770 DEG C, cold rolling at the rolling reduction of 72 to 92 %, conducting recrystallization annealing at 820 to 880 DEG C for at least 20 s, and cooling from this temperature to room temperature at a cooling rate of a least 3 DEG C/s. The obtained sheet contains carbon in solid solution form formed by dissolving deposited carbides through recrystallization annealing and has a recrystallization texture wherein the value of log(I{222}/I{200}) is 2.7 or above, wherein I{222} and I{200} are the intensities of diffraction of the {222} plane and the {200} plane, respectively, in X-ray diffractometry. The sheet is excellent in formability and workability in chemical conversion coating and high in work hardenability and baking hardenability. <IMAGE>
IPC 1-7
C22C 38/14; C21D 8/04; C21D 9/48; C23C 2/06; C23C 2/28; C25D 5/26
IPC 8 full level
C21D 8/04 (2006.01); C22C 38/14 (2006.01)
CPC (source: EP)
C21D 8/0426 (2013.01); C22C 38/14 (2013.01); C21D 8/0436 (2013.01); C21D 8/0473 (2013.01)
Designated contracting state (EPC)
DE ES FR GB IT
DOCDB simple family (publication)
EP 0572666 A1 19931208; EP 0572666 A4 19940601; EP 0572666 B1 19980506; DE 69225395 D1 19980610; DE 69225395 T2 19980910; ES 2114932 T3 19980616; WO 9214854 A1 19920903
DOCDB simple family (application)
EP 92905304 A 19920220; DE 69225395 T 19920220; ES 92905304 T 19920220; JP 9200181 W 19920220