受控脉冲穿孔PAW对接焊过程控制的试验研究  

Experimental Study on PAW Butt-welding Process with Controlled Pulse Key-holing Strategy

作　　者：刘祖明[1] 武传松[1] 陈茂爱[1] 

机构地区：[1]山东大学材料液固结构演变与加工教育部重点实验室,济南250061

出　　处：《机械工程学报》2011年第6期45-50,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金重点资助项目(50936003)

摘　　要：将受控脉冲穿孔等离子弧焊接系统应用于中厚度板的对接焊。对接焊工艺中板间存在的缝隙会对尾焰电压测量结果和穿孔状态带来不利影响,造成控制系统对穿孔状态误判而达不到良好焊接效果,需要对系统进行改进实现良好穿孔过程。基于受控脉冲控制策略和工件合理的装配,避免等离子弧从对接工件缝隙透过而引起的系统误判。开展6 mm和8 mm厚度304不锈钢平板的对接焊控制试验,找到合理的工艺参数。设计一组变厚度不锈钢板对接试验,考察系统在对接焊条件下的控制效果。控制系统根据测量的表征穿孔状态的尾焰电压信号,实时调节焊接电流峰值及其下降沿斜率;随着板厚的减小,系统做出快速调节,一脉一孔的动态过程平稳,控制效果显著,焊缝成形质量良好。The controlled pulse key-holing plasma arc welding system is used to conduct butt-welding of stainless steel plates of medium thickness.Joint gap exists in weld seam during the butting welding process and influences the measuring result of efflux plasma voltage and the stability of the controlling process,thus causes the control system to make misjudgment and fine welding quality cannot be attained,so the system should be improved to achieve a good key-holing process.Through employing the strategy of controlled pulse key-holing and appropriate joint fit-up,the system avoids any misjudgment when the plasma jet passes through the gap.Butt-welding experiments are carried out on type 304 stainless steel plates with thicknesses of 6 mm and 8 mm to get the optimum process parameters.A group of varied plate-thickness tests are designed and made to examine the effectiveness of the control system during butt welding.The control system makes in-process adjustment of welding current peak level and its dropping slopes according to the measured plasma efflux voltage.As the plate thickness gets less,the system gives fast and timely response.The dynamic process of one keyhole per pulse is stable,the control effect is remarkable,and the weld formation quality is good.

关 键 词：对接焊 受控脉冲穿孔控制策略 等离子弧焊接 

分 类 号：TH-55[机械工程]