Global Patent Index - EP 1262571 A1

EP 1262571 A1 2002-12-04 - STEEL HAVING WELD HEAT-AFFECTED ZONE EXCELLENT IN TOUGHNESS

Title (en)

STEEL HAVING WELD HEAT-AFFECTED ZONE EXCELLENT IN TOUGHNESS

Title (de)

STAHL MIT DURCH SCHWEISSEN BEEINFLUSSTER ZONE MIT AUSGEZEICHNETER ZÄHIGKEIT

Title (fr)

ACIER A ZONE AFFECTEE THERMIQUEMENT PAR SOUDAGE PRESENTANT UNE EXCELLENTE TENACITE

Publication

EP 1262571 A1 (EN)

Application

EP 00974966 A

Priority

  • JP 0007999 W
  • JP 2000033241 A
  • JP 2000033242 A
  • JP 2000068210 A

Abstract (en)

The present invention realizes excellent HAZ toughness by further suppressing the coarsening of austenite grains when they are heated for a long time at a high temperature in order to remarkably improve HAZ properties. The present invention is a steel excellent in the toughness of a weld heat-affected zone: having a specific chemical composition; satisfying the expression 0 </= EN </= 0.002 regarding the EN value expressed by an equivalent equation comprising (%N), (%Ti) and (%B); and containing oxide particles 0.005 to 2.0 mu m, preferably 0.1 to 2.0 mu m, in circle-equivalent diameter, which oxide particles contain at least Ca, Al and O in their composition and, in the mass percentage of the elements excluding O, contain Ca at 5% or more and Al at 5% or more with the balance consisting of other deoxidizing elements and/or unavoidable impurities, with the density of the oxide particles being 100 to 3,000 pieces/mm<2>. <IMAGE>

IPC 1-7 (main, further and additional classification)

C22C 38/00

IPC 8 full level (invention and additional information)

C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/14 (2006.01)

CPC (invention and additional information)

C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/14 (2013.01)

Designated contracting state (EPC)

DE FR

DOCDB simple family

EP 1262571 A1 20021204; EP 1262571 A4 20030326; EP 1262571 B1 20050810; DE 60021919 D1 20050915; DE 60021919 T2 20060608; DE 60033070 D1 20070308; DE 60033070 T2 20070531; EP 1520912 A2 20050406; EP 1520912 A3 20050427; EP 1520912 B1 20070117; WO 0159167 A1 20010816