Global Patent Index - EP 2612956 A1

EP 2612956 A1 20130710 - METHOD OF PRODUCING COLD-ROLLED STEEL SHEET AS WELL AS COLD-ROLLED STEEL SHEET AND MEMBERS FOR AUTOMOBILE

Title (en)

METHOD OF PRODUCING COLD-ROLLED STEEL SHEET AS WELL AS COLD-ROLLED STEEL SHEET AND MEMBERS FOR AUTOMOBILE

Title (de)

VERFAHREN ZUR HERSTELLUNG EINES KALTGEWALZTEN STAHLBLECHS, KALTGEWALZTES STAHLBLECH UND FAHRZEUGTEIL

Title (fr)

PROCÉDÉ DE PRODUCTION D'UNE TÔLE D'ACIER LAMINÉE À FROID, TÔLE D'ACIER LAMINÉE À FROID, ET ÉLÉMENT VÉHICULE

Publication

EP 2612956 A1 20130710 (EN)

Application

EP 11821648 A 20110825

Priority

  • JP 2011177865 A 20110816
  • JP 2010266123 A 20101130
  • JP 2010193179 A 20100831
  • JP 2011069192 W 20110825

Abstract (en)

This invention provides a method of producing a cold-rolled steel sheet being excellent in not only the phosphate treatability but also the corrosion resistance after coating under severe corrosion environment such as hot salt water immersion test or composite cycle corrosion test, wherein a continuously annealed steel sheet after cold rolling is pickled with a mixture of nitric acid and hydrochloric acid having a nitric acid concentration of more than 100 g/L but not more than 200 g/L and a ratio R (HCl/HNO 3 ) of hydrochloric acid concentration to nitric acid concentration of 0.01-0.25 to remove Si-containing oxide formed on the steel sheet surface by continuous annealing, and a ratio of covering the surface of the steel sheet with an iron-based oxide formed by the pickling is not more than 85% and preferably a maximum thickness of the iron-based oxide existing on the surface of the steel sheet is not more than 200 nm, as well as a cold-rolled steel sheet produced by this method and a member for automobile using the cold-rolled steel sheet.

IPC 8 full level

B21B 3/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/58 (2006.01); C23G 1/08 (2006.01)

CPC (source: EP KR US)

B21B 3/02 (2013.01 - KR); C21D 8/0205 (2013.01 - EP KR US); C21D 8/0226 (2013.01 - EP KR US); C21D 8/0236 (2013.01 - EP KR US); C21D 8/0273 (2013.01 - EP KR US); C21D 9/46 (2013.01 - EP KR US); C22C 1/02 (2013.01 - KR); C22C 38/00 (2013.01 - EP KR US); C22C 38/001 (2013.01 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/005 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/06 (2013.01 - EP US); C22C 38/12 (2013.01 - EP US); C22C 38/14 (2013.01 - EP US); C22C 38/16 (2013.01 - EP US); C22C 38/22 (2013.01 - EP US); C22C 38/32 (2013.01 - EP KR US); C22C 38/34 (2013.01 - EP US); C22C 38/38 (2013.01 - EP US); C22C 38/58 (2013.01 - KR); C23G 1/00 (2013.01 - EP US); C23G 1/08 (2013.01 - EP US); C23G 1/085 (2013.01 - EP KR US); B21B 3/02 (2013.01 - EP US); Y10T 428/265 (2015.01 - EP US)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DOCDB simple family (publication)

EP 2612956 A1 20130710; EP 2612956 A4 20150318; EP 2612956 B1 20160601; CN 102959129 A 20130306; JP 2012132093 A 20120712; JP 5835558 B2 20151224; KR 20130031284 A 20130328; TW 201224215 A 20120616; TW I454594 B 20141001; US 2013149529 A1 20130613; WO 2012029631 A1 20120308

DOCDB simple family (application)

EP 11821648 A 20110825; CN 201180029545 A 20110825; JP 2011069192 W 20110825; JP 2011177865 A 20110816; KR 20127033101 A 20110825; TW 100131124 A 20110830; US 201113812438 A 20110825