高强度粉末冶金零件的电阻凸焊组合

RESISTANCE PROJECTION WELDING ASSEMBLE OF HIGH STRENGTH P/M PARTS

研究了Ｆｅ－Ｃ－Ｃｕ－Ｎｉ－Ｍｏ系高强度粉末冶金零件的电阻凸焊工艺以及焊前和焊后热处理对焊接强度的影响。结果表明，粉末冶金制品在适当的焊接规范下表现出良好的可焊性。在本实验条件下，最佳焊接参数为：电极压力Ｐ＝０．３ＭＰａ；焊接电压Ｕ＝６．０Ｖ；焊接时间ｔ＝０．５５ｓ。辉前的预热处理不利于提高焊接性能，焊后经８６０℃淬火及２００℃回火有利于改善焊区的显微组织，提高焊接强度。电阻凸焊工艺已成功应用于轿车柴油发动机ＶＥ分配泵中的一对零件。

The paper studies resistance projection technology of Fe-C-Cu-Ni-Mo system high strength P/M parts and the influence of heat treatment before and after welding on welding strength. The results show that with appropriate welding criterion,P/M products exhibit superior weldability. The optimum welding parameters under the conditions of present experiments are: electrode pressure P=0.3MPa,welding voltage U=6.0V and welding time=0.55s. The pretreatment before welding is unfavourable for improving welding properties.Quenching at 860℃and tempering at 200℃ after welding is favourable for imoroving microstructure in welding area and enchancing welding strength. Resistance projiction welding technology has been successfully used for a pair of parts in VE distributingpump of car diesel engine.