脉冲MIG焊不稳定过渡过程的观察与分析

基于高速摄像和电信号分析系统,采集了一定焊接工艺参数下脉冲MIG焊焊接过程的电信号,借助电信号小波分析设备对不稳定焊接过程进行了宏观分析,并对焊接熔滴过渡过程中的不稳定现象进行了高速摄像观察.观察发现,脉冲MIG焊不稳定焊接过程呈现出多种熔滴过渡形式,过渡熔滴形状多样,熔滴尺寸不均匀,熔滴形成过程中重心不稳,熔滴爆炸引起飞溅以及熔池振荡.通过对焊接过程不稳定现象的观察与分析,指出焊丝熔化能量的随机性以及熔滴上综合作用力的随机性是熔滴尺寸具有不确定性的根源.对脉冲MIG焊焊接过程不稳定现象的研究将有利于对焊接工艺性能进行有效控制.

Observation and analysis of unstable metal transfer process in pulsed MIG welding

Based on the high-speed video system and electrical signals analyzing in synchronous, the electrical signals and the photographs of molten droplet under certain welding parameters was collected, the unstable phenomenon of welding process in pulsed MIG welding was studied.It was observed that the unstable welding process of the pulsedMIG welding presented various forms of droplet transfer, the shape and size of molten drop were diverse, the barycenter of melting drop was unstable, droplet exploding brought spatter and the weld pool oscillation.Based on the observation and analysis of the unstable phenomenon of the welding process, it is pointed out that the random variation of melting energy of electrode tip and the forces exerted on the droplet are the vital reasons of the random variation of the drop shape and size.The study on the unstable phenomena of pulsedMIG welding process is helpful to the control of welding technical performance.