公开(公告)号：JP2007002289A

公开(公告)日：2007-01-11

申请号：JP2005182690

申请日：2005-06-22

Applicant: NAT INST FOR MATERIALS SCIENCE

Inventor： KIYU UMI ,  NISHIMURA TOSHIYA ,  HIRAOKA KAZUO

IPC: C22C38/00 ,  C22C38/06 ,  F16B11/00

Abstract: PROBLEM TO BE SOLVED: To provide a weld joint having controlled and improved bond hardness and bond notch toughness even when having a high carbon-equivalent composition, by adding a larger amount of Al and Si elements which are not included in or do not give remarkable influence on a carbon equivalent formula and a P CM formula but work for forming ferrite than those contained in a conventional steel for a welded structure. SOLUTION: This weld joint is formed by welding a steel for the welded structure which has a basic composition expressed by Fe-C-Mn-Si-Al, and comprises 0.03-0.3 wt.% C, 0.5-2.5 wt.% Mn, 0.15-2.5 wt.% Si, 0.01-1.5 wt.% Al, P restricted to less than 0.15 wt.%, S restricted to less than 0.05 wt.%, and unavoidable impurities; and has the bond notch toughness of 27 J or higher at 0°C and the bond hardness of 400 HV or lower. COPYRIGHT: (C)2007,JPO&INPIT