摘要
采用单电极和双电极分别对400MPa级超细晶粒钢进行电阻点焊，研究了点焊接头组织和性能。试验结果表明超细晶粒钢电阻点焊接头熔核区几乎由方向性很强的柱状晶组成，组织以脆硬的马氏体为主；双电极点焊时，环形电极对热影响进行加热，细化了热影响区粗晶区晶粒组织，消除了脆硬的马氏体组织，提高了点焊接头拉剪强度。
400MPa ultra fine--grained steel is welded by the resistance spot welding with single--electric and two--elec- tric, the microstructure and properties of resistance spot welding joint are investigated, the results showed that the nugget grain shape of ultra fine--grained steel joint consists of coarse and oriented columnar grains, the microstructure is harden mar- tensite. When welding with two--electric, the HAZ is heated by the annular electric, the coarse grains in the HAZ are re- fined, harden rnartensite is eliminated and the shearing strength of joints are increased.
出处
《中国材料科技与设备》
2015年第4期18-20,共3页
Chinese Materials Science Technology & Equipment
基金
航空科学基金项目（2011ZE56005）
江西省教育厅科技计划项目（GJJ13496）
关键词
微观组织
超细晶粒钢
电阻点焊
Microstructure
Ultra fine--grained steel
Resistance spot welding
