Global Patent Index - EP 0462779 A3

EP 0462779 A3 19930901 - METHOD OF MAKING STEEL USEFUL IN SPRINGS

Title (en)

METHOD OF MAKING STEEL USEFUL IN SPRINGS

Publication

EP 0462779 A3 19930901 (EN)

Application

EP 91305456 A 19910617

Priority

  • JP 2507691 A 19910128
  • JP 2507791 A 19910128
  • JP 15879090 A 19900619

Abstract (en)

[origin: EP0462779A2] Steel material containing by weight from 0.4 % to 0.8 % carbon, from 0.5 % to 2.5 % silicon, from 0.3 % to 2.0 % manganese, from 0.1 % to 1.5 % chromium, and from 0.1 % to 0.5 % molybdenum is hot-rolled to form a strip or plate. The hot-rolled plate or strip is annealed and cold-rolled at a rolling reduction between 10 % and 80 %. The cold-rolled strip or plate is heated at a temperature above Ac3 critical point for a time sufficient to austenitize carbide and annealed. Steel springs with attractive properties for use in motor vehicle clutches can be produced from this steel material.

IPC 1-7

C21D 8/02; C21D 9/02

IPC 8 full level

C21D 6/02 (2006.01); C21D 8/02 (2006.01); C21D 9/02 (2006.01)

CPC (source: EP KR)

C21D 6/02 (2013.01 - EP); C21D 8/0273 (2013.01 - EP); C21D 9/02 (2013.01 - EP); C22C 38/02 (2013.01 - KR); C22C 38/04 (2013.01 - EP); C22C 38/22 (2013.01 - EP); C22C 38/24 (2013.01 - EP); C22C 38/26 (2013.01 - EP); C22C 38/34 (2013.01 - EP); C21D 8/0226 (2013.01 - EP); C21D 8/0236 (2013.01 - EP); C21D 8/0263 (2013.01 - EP)

Citation (search report)

  • [A] FR 1290235 A 19620413 - CT TECH DE L IND HORLOGERE
  • [A] US 4770721 A 19880913 - YAMAMOTO TOSHIRO [JP], et al
  • [XP] PATENT ABSTRACTS OF JAPAN vol. 14, no. 559 (C-787)12 December 1990 & JP-A-02 240 240 ( AISIN SEIKI ) 25 September 1990

Designated contracting state (EPC)

DE FR GB

DOCDB simple family (publication)

EP 0462779 A2 19911227; EP 0462779 A3 19930901; EP 0462779 B1 19960911; AU 633737 B2 19930204; AU 7837391 A 19920109; CA 2044639 A1 19911220; CA 2044639 C 20010828; DE 69121982 D1 19961017; DE 69121982 T2 19970130; KR 920000959 A 19920129; KR 930012177 B1 19931224

DOCDB simple family (application)

EP 91305456 A 19910617; AU 7837391 A 19910613; CA 2044639 A 19910614; DE 69121982 T 19910617; KR 910010243 A 19910619