活性剂对镁合金直流正接A-TIG焊熔深的影响

Effects of activating fluxes on DCSP A-TIG weld penetration of magnesium alloy

分别以单质Te,Ti和Si,氧化物SiO2,TiO2和V2O5,卤化物MnCl2,CdCl2和ZnF2作为表面活性剂进行了镁合金直流正接A-TIG焊,研究了活性剂对焊缝熔深的影响规律。Te能显著增加熔深熔宽,分别达到传统TIG焊的2.5倍和1.4倍,而Ti和Si对熔深熔宽影响较小;V2O5和SiO2都使得熔深熔宽同时增加,其中SiO2增加熔深熔宽效果最明显,分别达到传统TIG焊的2.0倍和1.6倍,而TiO2对熔深熔宽影响较小;ZnF2,Cd-Cl2和MnCl2都使熔深熔宽显著增加,其中ZnF2的熔深熔宽增加最明显,分别达到传统TIG焊的4.0倍和1.6倍。认为活性剂增加镁合金直流正接A-TIG焊熔深主要与活性剂收缩电弧所导致的热输入增加有关。

DCSP (direct current straight polarity) A-TIG (activating-tungsten inert gas) welding experiments of magnesium alloy were carried out to study the effects of surface activating fluxes on weld penetration. Elements including Te, Ti and Si, and oxides including SiO2, TiO2 and V2O5, and halides including MnCl2, CdCl2 and ZnF2 were used as activating fluxes, respectively. It is found, the weld penetration and width of Te powder reach 2.5 times and 1.4 times of those of conventional TIG welding, respectively. Ti and Si have small effects. Both V2O5 and SiO2 increase weld penetration and width. Especially for SiO2, the weld penetration and width reach 2.0 and 1.6 times of those of conventional TIG welding. TiO2 has small effect. All ZnF2, CdCl2 and MnCl2 increase weld penetration and width obviously. The effect of ZnF2 is the most dramatic. The weld penetration and width reach 4.0 and 1.6 times of those of conventional TIG welding. It is believed that, the mechanism of activating fluxes improving weld penetration of DCSP A-TIG welding of magnesium alloy is relative to heat input increase because of activating fluxes constricting arc.