脉冲熔化极气体保护焊熔滴过渡电信号特征及建模

Modeling of droplet transfer electrical characteristics in pulsed gas melted arc welding

脉冲熔化极气体保护焊(GMAW-P)熔滴过渡形式对焊接质量有着重要的影响,同时脉冲参数是影响GMAW-P熔滴过渡行为的主要参数.利用高速数字摄像技术,记录熔滴过渡过程,同时采集焊接过程的电流、电压信号,并将各个信息传输到PC机中,实现数据的保存.综合分析熔滴过渡图片与对应的电信号的关系,提取了GMAW-P熔滴过渡过程特征电信号.通过统计分析建立了GMAW-P熔滴过渡逻辑回归模型.结果表明,此模型预测熔滴过渡的正确率达93%,为实现一脉一滴最佳脉冲熔滴过渡形式闭环控制开辟了新的途径.

Metal droplet transfer mode which is influenced by the pulse parameters such as pulse current (Ip),pulse time (tp),base current (Ib) and pulse frequency (f) has play an important role in the weld quality. An experimental system based on the Lab VIEW virtual instrument and high speed photography technology was developed to sample the transient electrical parameters and record the images of droplet transfer process simultaneously. A transition voltage Udd in the pulse voltage drop edge of electrical waveform was discovered according to analysis of synchronous electric and image signals. The relationship between the metal transfer mode and the slope of the transition voltage was proposed.The result of experiments shows that the model can be used in closed-loop controlling of one droplet per pulse transfer mode and also can help for optimizing the welding parameters.