GMAW短路过渡过程中瞬时短路现象的分析  

Instantaneous short circuit in short circuiting transfer process in GMAW

作　　者：王广伟[1] 蔡艳[1] 华学明[1] 吴毅雄[1] 

机构地区：[1]上海交通大学焊接工程研究所,上海200030

出　　处：《焊接学报》2007年第9期43-46,102,共5页Transactions of The China Welding Institution

基　　金：上海市科学技术委员会科研计划项目资助(036105001)

摘　　要：对GMAW短路过渡过程中的瞬时短路现象进行了力学动态分析,建立了基于熔滴液体压力、电磁收缩力、表面张力的瞬时短路力动态平衡临界条件。通过微距高速摄影技术和图像处理技术,获得了熔滴半径的变化数据,并结合电信号分析。结果表明,计算所得数值所反映的短路进程状态和图像所示的完全吻合,认为瞬时短路力动态平衡临界条件真实有效。并进一步基于此临界条件分析了熔滴形态对瞬时短路的影响,认为熔滴和熔池接触瞬间的径向半径如果小于轴向半径,则接触处的径向表面张力所产生的压力大于零,瞬时短路开始且不可逆,即纺锤形熔滴易造成瞬时短路。最后对瞬时短路现象进行了分类和定量研究,并提出了瞬时短路现象的新的解释。The critical condition of dynamic force equilibrium of instantaneous short circuit(ISC) in GMAW(gas metal arc welding) based on droplet pressure,electromagnetic force,and surface tension was presented while the dynamic force was analyzed.Based on micro focus high speed photography technique and digital image processing technology,the data of the droplet radius were obtained.And the electric signal was combimed and analyzed.The results showed the short circuiting process reflects by the calculated data completely agreed with that from the images.The critical condition is proved.Further,the influence of the droplet shape on the ISC was analyzed based on this critical condition.If the radial radius was less than axial radius when the droplet touched with the wolten pool,the radial surface tension would be positive.The ISC startes and can not be reversed,which means the spindly droplet leads to ISC frequently.Lastly,the ISC phenomena was classified and studied quantificationally.And the new explanation of ISC was proposed.

关 键 词：力动态平衡 瞬时短路 熔化极气体保护焊 

分 类 号：TG434[金属学及工艺—焊接]