钨/钢异种金属电阻扩散焊接头组织与性能  

Interfacial Microstructure and Mechanical Properties of Tungsten/steel Dissimilar Joints by Resistance Diffusion Welding

作　　者：于江 唐小雅[2] 孙宇 张洪涛[2] 杨涛[1] YU Jiang;TANG Xiaoya;SUN Yu;ZHANG Hongtao;YANG Tao(Ningbo Institute of Materials Technology&Engineering,Chinese Academy of Sciences,Ningbo 315201;National Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin 150001)

机构地区：[1]中国科学院宁波材料技术与工程研究所,宁波315201 [2]哈尔滨工业大学材料结构精密焊接与连接全国重点实验室,哈尔滨150001

出　　处：《机械工程学报》2024年第20期173-180,共8页Journal of Mechanical Engineering

基　　金：济宁市全球揭榜资助项目(2022JBZP004)。

摘　　要：提出高电阻率石墨作为热补偿辅助电极,纯Fe箔作为中间层,在一定焊接时间下,通过电阻缝焊输出的恒定电流产生的焦耳热实现纯钨板与CLF-1低活化铁素体/马氏体(RAFM)钢的电阻扩散焊连接。同时,对比获得的钨/钢和钨/铁/钢焊接接头的界面组织、接头强度和断裂形式去揭示中间层在焊接过程中的作用机制。结果表明:由于钨/钢异种金属界面之间引入了中间层,获得的钨/铁/钢焊接接头的界面结构发生显著变化,由原来的钨/钢连接界面转变为钨/铁界面和铁/钢界面,同时,中间层的加入会导致整个焊接接头电阻增加,焊接过程中生成的焦耳热增多,导致界面处元素相互扩散距离增加,由原来的2μm增加至4μm,获得的焊接接头剪切载荷得到提高,为12313.3 N,相对前者提高约30.82%,接头表面实时温度场表明整个焊接过程中辅助电极石墨的温度最高,达到910℃,但小于母材熔点,这亦表明整个焊接过程界面以扩散为主,为电阻固相扩散连接。此外,断口形貌表明中间层的加入导致断口处反应区域增加,主要断裂位置位于钨合金处,表明钨/钢之间形成较好的冶金结合。The pure tungsten plate and the CLF-1 reduced activation ferritic/martensitic(RAFM)steel was welded successfully based on the Joule heat generated by the constant current output from the resistance seam welding,named resistance diffusion welding.Meanwhile,the graphite with high resistivity and the pure Fe foil were proposed as the thermal compensated auxiliary electrode and the interlayer in the welding process,respectively.The interfacial structure,joint strength,and fracture form of the obtained W/steel and W/Fe/steel welded joints were compared to reveal the role of the interlayer in the welding process.The results indicated that:due to the introduction of the interlayer between tungsten and RAFM steel,the interfacial structure of the obtained W/Fe/steel welded joint was changed significantly.The original W/Fe connection interface was replaced by two interfaces of W/Fe and Fe/steel.In addition,the addition of the interlayer led to an increase in the resistance of the entire welded joint,which improved the Joule heat generated in the welding process.Hence,the interdiffusion distance at the interface increased from 2μm to 4μm,and the obtained shear load of the W/Fe/steel welded joint reached 12313.3 N,which was about 30.82%higher than the former.The real-time temperature field of the W/Fe/steel welded joint surface showed that the temperature of the auxiliary electrode graphite was the highest in the whole welding process.The highest temperature was 910℃but was lower than the melting point of the base metal.This indicated that the mechanical properties of the welded joints were dominated by the interdiffusion of different elements,which was resistance diffusion welding.Moreover,the fracture morphology sketched that the addition of the interlayer resulted in the increase in the reaction area at the fracture surface,and the main fracture position was located at the W side,indicating that a good metallurgical bond was formed between tungsten and RAFM steel.

关 键 词：电阻扩散焊 焦耳热 钨 低活化铁素体/马氏体钢 

分 类 号：TG453[金属学及工艺—焊接]