轿车电控喷油器脉冲激光焊研究

Research on the laser pulse welding of fuel injector for car

研究了轿车电控喷油器喷孔零件的脉冲激光焊工艺参数特征,详细分析了脉冲激光焊焊缝的组织特征,主要为奥氏体枝晶和等轴晶,焊缝边界处枝晶结晶方向垂直于熔合线指向焊缝中心,到焊缝中部枝晶的结晶方向变得杂乱,开始出现等轴晶。部分焊缝组织晶粒特征有明显的分层现象,通过分析脉冲激光焊重叠度和熔池液态金属的流动特性,解释了晶粒特征的分层现象。随着脉冲峰值功率密度的加大,焊缝容易出现根部气孔、塌陷、裂纹等缺陷。

This paper researched the laser pulse welding process parameters of pulverization hole plate of engine＇s fuel injector for car,the microscopic structure of welding metal of the engine＇s fuel injector has been deeply investigated：the fusion zone of the welding metal is austenitic crystal in tree＇s form,the closed neighbor zone of fusion to the direction of welding center line is austenitic grain in form of tree mixed with equiaxial grain,and the center of weld bond is equiaxial grain.The layered phenomenon of weld grain characteristics has been discovered and the further study showed that pulse peak ladder density and eddy current of key hole effect is the main cause of layer formation in welding pool.With much more great the laser pulse peak power become,it could causes defects of gas pore,surface depression even crack etc in melding bond.