摘要
动态CMT焊接是对传统CMT焊接的改进,以期获得较大的熔深。采用高速摄像同步分析系统分析了动态CMT焊接过程熔滴过渡和电流电压波形特点。结果发现,动态CMT焊接熔滴过渡增高至110 Hz以上;从电流电压波形上看,动态CMT分为3个阶段,即燃弧,强脉冲和短路3个阶段。在强脉冲阶段,电流峰值达493 A,而在短路阶段电流为75 A以上。T形接头焊接结果显示,在相同焊接热输入下,动态CMT比普通CMT能够获得更大的熔深.熔深增加是由于强脉冲阶段大的电弧力造成熔池表面下凹,电弧下方液态金属层变薄使得熔池底部加热作用明显;同时短路电流的增加,也提高了熔池温度和焊丝预热效果。
In order to get a deeper penetration,dynamic CMT welding process is an improvement of conventional CMT welding process.The characteristics of droplet transfer and waveforms of welding current and arc voltage were analyzed by high speed camera synchronous system.The result showed that the frequency of droplet transfer is higher than 110 Hz.From the waveforms of welding current and arc voltage,dynamic CMT can be divided into three periods,namely,arcing,strong pulse and short circuiting.During the strong pulsed current period,the peak current is 493 A and it is higher than 75 A during the short circuit period.The result of T- joint welding showed that dynamic CMT can achieve greater penetration than conventional CMT does at the same heat input,the increase of penetration is due to the strong arc during the strong pulse period,which causes a concave weld pool surface,a thinner liquid metal layer below the arc and a more efficiency heating effect on the weld pool bottom.Meanwhile the increased short- circuiting current also improves the temperature of the molten pool and welding wire.
出处
《焊接》
北大核心
2015年第7期10-13,73,共4页
Welding & Joining
基金
国家自然科学基金项目(51005069
51205106)
