铝合金气体输送活性钨极氩弧焊方法

Gas transfer flux activating TIG welding process for aluminum alloy

关键词:  气体输送活性钨极氩弧焊  铝合金  电弧收缩  活性剂

Key words:  GTFA-TIG welding  aluminum alloy  arc contraction  activating flux

摘要:

针对铝合金,提出了一种气体输送活性钨极氩弧焊,即GTFA-TIG焊(gas transfer flux activating TIG welding).该方法改变了活性元素的引入方式,通过自动送粉装置将活性剂输送到保护气体中,由保护气体将其引入电弧-熔池系统进行施焊,使得电弧收缩,熔池金属流态改变,熔深增加,同时省却了涂覆活性剂工序,实现了焊接过程自动化.进行了普通交流TIG焊和8种单组元活性剂的GTFA-TIG表面熔焊,分析了不同活性剂对焊缝成形、拉伸性能以及缺陷的影响.结果表明,大多数卤化物和氧化物活性剂都能使熔深增加到传统TIG焊的2.5~3倍以上,单质碲增加熔深效果较差.采用V₂O₅的焊缝抗拉强度接近母材金属,而采用MnCl₂和AlF₃的焊缝有一定程度降低.焊缝X射线探伤结果表明,采用V₂O₅,MnCl₂和AlF₃的焊缝评片结果均为Ⅰ级,而采用碲的焊缝为Ⅲ级.

Abstract:

A new activating TIG welding process,gas transfer flux activating TIG (GTFA-TIG) welding,is proposed for welding aluminum alloy by changing the introduction method of active elements. In this process,a flux is transferred to shielding gas through an automatic powder feeder,and the shielding gas carries the active elements into the welding arc and weld pool. In this way,the welding arc is contracted,and the flow pattern in the weld pool is changed,finally,the weld depth increases. Without coating the flux,the automation of welding process is realized. Compared to the conventional AC TIG welding, the effects of fluxes on the weld shape,tensile property and defects of GTFA-TIG welding with eight kinds of single-component fluxes were investigated. It proves that most of halide and oxide fluxes can improve the weld depth up to 2.5-3.0 times of that of traditional TIG welding,while the effect of Te flux is less effective. The tensile strength of the joint with V₂O₅ flux is close to that of base metal,but it is lower than that of base metal when using MnCl₂ and AlF₃ fluxes. The X-ray detection of defects shows that the welds with V₂O₅,MnCl₂ and AlF₃ fluxes are assessed as grade I,while that with Te flux is grade III.