Global Patent Index - EP 1731625 B1

EP 1731625 B1 20191009 - STEEL WIRE FOR SPRING

Title (en)

STEEL WIRE FOR SPRING

Title (de)

STAHLDRAHT FÜR FEDER

Title (fr)

FIL D'ACIER POUR RESSORT

Publication

EP 1731625 B1 20191009 (EN)

Application

EP 05709768 A 20050204

Priority

  • JP 2005001703 W 20050204
  • JP 2004027891 A 20040204

Abstract (en)

[origin: EP1731625A1] The present invention provides a spring steel wire which has a tempered martensitic structure brought about by quenching-tempering. The present spring steel wire has a 40 % or higher reduction of area and a 1,000 MPa or higher shear yield stress after subjected to heat treatment for at least 2 hours at a temperature ranging from 420°C to 480°C. The present steel wire preferably constitutes, based on mass %, C: 0.50-0.75%, Si: 1.80 2.70%, Mn: 0.1-0.7%, Cr: 0.70-1.50%, Co: 0.02 - 1.00%, and remnants consisting of Fe and impurities, or constitutes, based on mass %, C: 0.50-0.75%, Si: 1.80-2.70%, Mn: over 0.7-1.50%, Cr: 0.70-1.50%, and remnants consisting of Fe and impurities.

IPC 8 full level

C22C 38/00 (2006.01); F16F 1/02 (2006.01); C21D 1/20 (2006.01); C21D 1/25 (2006.01); C21D 8/06 (2006.01); C21D 9/52 (2006.01); C22C 38/30 (2006.01); C22C 38/34 (2006.01); C22C 38/52 (2006.01); C21D 1/18 (2006.01)

CPC (source: EP KR US)

C21D 1/18 (2013.01 - KR); C21D 1/20 (2013.01 - EP KR US); C21D 1/25 (2013.01 - EP KR US); C21D 8/065 (2013.01 - EP KR US); C21D 9/02 (2013.01 - EP KR US); C21D 9/525 (2013.01 - KR); C22C 38/30 (2013.01 - EP KR US); C21D 1/18 (2013.01 - EP US); C21D 9/525 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP KR US)

Citation (examination)

US 6224686 B1 20010501 - AOKI TOSHINORI [JP], et al

Designated contracting state (EPC)

DE FR GB IT SE

DOCDB simple family (publication)

EP 1731625 A1 20061213; EP 1731625 A4 20120328; EP 1731625 B1 20191009; CN 100449026 C 20090107; CN 1914347 A 20070214; JP 2005220392 A 20050818; JP 4357977 B2 20091104; KR 101096888 B1 20111222; KR 20060129019 A 20061214; US 2008271824 A1 20081106; WO 2005075695 A1 20050818

DOCDB simple family (application)

EP 05709768 A 20050204; CN 200580003962 A 20050204; JP 2004027891 A 20040204; JP 2005001703 W 20050204; KR 20067016315 A 20060814; US 58828705 A 20050204