30CrMnSiNi2A钢焊接冷裂纹的敏感性

Susceptibility to Welding Cold Cracking of 30CrMnSiNi2A

采用插销试验测试了不同情况下30CrMnSiNi2A钢焊接熔合区的临界断裂应力,分析了插销焊接接头的组织和插销试样的断口形貌。结果表明：30CrMnSiNi2A钢插销焊接接头上冷裂纹最敏感的区域是熔合区,其断口形貌为沿晶+准解理；熔合区晶粒粗大,组织为马氏体+贝氏体+残余奥氏体；HTJ-3焊条扩散氢含量大于HTG-1焊条,前者临界断裂应力小于后者；缺口影响插销焊接接头的应力分布。

Implant test equipment was used to measure critical fracture stresses of the fusion area under different conditions. Microstructure of the joints and fracture morphology of implant samples were analyzed. The zone of the most susceptibility to cold cracking was the fusion area in implant welding joints. The fracture morphology of the fusion area was in intergranuar form with a few quasicleavage. The microstructure of the fusion area was a combination of martensite, bainite and retained austenite. The hydrogen content of HTJ-3 electrode was more than that of HTG-1 electrode, so the critical fracture stress of the former fusion area was less than that of the latter. Stress distribution in implant welding joint were affected by the notch.