异种钢接头熔合区的脆化与断裂行为  

Embrittlement and Fracture Behavior of Fusion Zone in Dissimilar Steel Welded Joints

作　　者：杜兵[1] 李彦[1] 贾玉力[1] 

机构地区：[1]哈尔滨焊接研究所

出　　处：《焊接学报》1998年第1期8-12,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金;机械工业技术发展基金

摘　　要：根据分层止裂原理设计了异种钢熔焊接头的冲击断裂试样，采用示波冲击功定量评定了熔合区的脆化行为，利用扫描电镜分析了熔合区的断裂机制，并研究了不同焊接材料及焊后热处理工艺规范对熔合区脆化与断裂行为的影响。研究结果表明，焊态熔合区的脆化主要是由马氏体引起的，其断裂机制为马氏体的解理开裂。热处理后熔合区的脆化主要是由增碳层与脱碳层引起的，熔合区的断裂机制为析出碳化物的无特征开裂及脱碳层的沿晶开裂。对于不同的过渡层焊接材料，熔合区的断裂机制没有本质的区别，但其脆化程度存在明显的差异。经热处理以后，ＨＤ３０９Ｌ作过渡层的熔合区的脆化指数Ｅｂ是ＨＤ４５７Ｌ作过渡层的熔合区的１．５倍；而焊态脆化指数Ｅｂ，ＨＤ３０９Ｌ是ＨＤ４５７Ｌ的４倍。On the basis of separation crack-arrest principle, a special chary impact specimen was designed for the quantitative evaluation on embrittlement behavior of fusion zone in dissimilar steel weleded joints by using Charpy Instrument Tester. The fracture mechanism was studied with SEM. The effects of different butter layers and PWHT parameters on embrittelment and fracture behavior of fusion zone were also discussed. The results indcated that embrittlement of fusion zone as welded was caused by the martensite,and the fracture morphology was cleavage in martensite layers. After PWHT the embrittelment was mainly caused by the carbon enriched / depleted layers, and the fracture morphology was carbide and /or an intergranular fracture. There was no significant influence of different butter layers on the embrittlement and fracture mechanism,but great influence of different butter layers on the embrittlement grade existed. After PWHT the embrittlement index (Eb) of fusion zone for HD309L butter layer was higher than that for HD457L butter layer by one and half times,and by four times as welded.

关 键 词：异种钢 熔合区 脆化 断裂 焊接 接头 

分 类 号：TG407[金属学及工艺—焊接] TG457.11