冷却方式对72钢对焊组织及性能的影响

Effect of cooling mode on microstructure and properties of 72 steel butt welding

用光学显微镜、拉伸和扭转试验研究了冷却方式对72钢显微组织和力学性能的影响。结果表明:72钢接头组织为回火索氏体+少量珠光体+少量铁素体,5.5 s回火时,随着冷却方式转变,钢丝接头组织构成由索氏体+珠光体变为索氏体+少量珠光体+少量铁素体,接头抗拉强度和扭转性能均逐渐升高,油冷条件下,焊接接头具有较好的强度塑性配比,满足3.08 mm钢丝对焊工艺要求。

To study effects of cooling mode on microstructure and mechanical properties of 72 steel by optical microscope,tensile and torsion tests.Results show that microstructure of 72 steel joint is tempered sorbite,small amount of pearlite and small amount of ferrite.During 5.5 s tempering,with change of cooling mode,microstructure of steel wire joint changes from sorbite and pearlite to sorbite,small amount of pearlite and small amount of ferrite.Tensile strength and torsion of joint gradually increase,oil cooling reaches the highest value,and has a good strength plastic ratio,which can be used as butt welding process of diameter 3.08 mm steel wire.