焊后调质对30CrMo合金钢摩擦焊接头组织及性能的影响

Effect of postweld quenching and tempering on microstructures and properties of friction welded joint of 30CrMo alloy steel

文中对30CrMo轮对空心轴与三爪盘摩擦焊接头进行焊后调质(淬火+回火)热处理,研究了接头分别在焊态和焊后调质态时的组织形貌和力学性能(拉伸、弯曲、冲击、硬度),以确定焊后调质工艺对30CrMo摩擦焊接头性能的影响。研究结果表明:经调质处理后的30CrMo合金钢摩擦焊接头抗拉强度和屈服强度有较大提升,分别达到了母材的69%和65%;无论是室温还是-40℃,断后伸长率和收缩率变化不大,调质后接头各部位试件强度均达到27 J以上;冲击断口在焊缝区呈准解理,在热影响区和母材呈韧窝密集的混合型断裂,较焊态接头其冲击性能提高显著。

In this paper,the 30 CrMo wheel-to-hollow shaft and the three-claw disk friction welded joint were subjected to postweld quenching and tempering(quenching+tempering)heat treatment.The microstructures and mechanical properties(tensile,bending,impact,hardness)of the joint in the as-welded and postweld tempering states were investigated to determine the effect of the postweld quenching and tempering process on the performances of the 30 CrMo friction welded joint.The results showed that the tensile strength and yield strength of the friction welded joint of 30 CrMo alloy steel after quenching and tempering were greatly improved,reaching 69%and 65%of the base metal respectively.No matter at room temperature or-40℃,the elongation and shrinkage after breakage did not change much,and the strength of the test pieces at all parts of the joint after quenching and tempering reached27 J or more.The impact fracture was quasi-cleaved in the weld zone,and the mixed fracture of the base material in the heat affected zone and the base material was dense,and the impact performance of the welded joint was improved significantly.