HIGH TENSILE STEEL HAVING SUPERIOR STRESS RELIEF ANNEALING EMBRITTLEMENT CHARACTERISTIC AT WELD HEAT AFFECTED ZONE

摘要

PURPOSE:To obtain the titled high tensile steel having superior annealing embrittlement characteristics by adding a predetermined amount of Nb and/or V to a high tensile steel contg. C, Si, Mn and Al. CONSTITUTION:The titled high tesile steel is obtd. by adding Nb and/or V to an Si-Mn steel consisting of, 0.05-0.2wt% C, 0.1-1% Si, 0.3-2% Mn, =0.1% total Al and the balance Fe and having =40kg/mm.2 tensile strength. The amount of Nb and/or V added is as follows: 0.01=Nb(%)=0.04 or 0.01=V(%)=0.1 in case Nb or V is added and 0.02=3Nb(%)+V(%)=0.09 in case Nb and V are added.