不锈钢材料的高效率焊接新工艺

HIGH EFFICIENCY WELDING PROCESS FOR STAINLESS STEEL MATERIALS

针对不锈钢材料钨极惰性气体保护(TIG)焊熔深浅、焊接效率低的缺点开发了大深宽比高效率TIG焊接新工艺,包括活性剂焊接工艺、混合气体联合保护焊工艺和双层气流保护焊工艺.与涂覆活性剂法相比,混合气体法不仅可获得深熔深,而且操作方便,易于实现工业化;双层气流法可有效避免混合气体法中电极氧化烧损现象.实验和模拟结果表明:熔池中活性元素O含量变化导致的Marangoni对流方向的变化是TIG焊熔深增加的主要因素,焊接过程中调整液态熔池中活性组元含量可获得大深宽比焊缝.高效率TIG焊接工艺对焊接规范(焊接速度、焊接电流和电极间距)不敏感,有利于在工业生产中推广应用.

The high efficiency tungsten inert gas （TIG） welding process has been developed, including active flux welding process, mixed shielded welding process and double shielded welding pro- cess, to increase the weld depth/width ratio （D/W） of conventional TIG welding method. Compared to the active flux method, mixed shielding method can make penetration deeper and the industrialization can be realized easily due to the simplification in operation. Double shielded method can avoid the oxidation of tungsten electrode. The results of experiment and simulation show that the change of the Marangoni convection direction which arises from the adjustment of the oxygen content in the weld pool is one of the main factors contributing to the increase in TIG weld penetration, and the large D/W ratio can be obtained by adjusting the active element content in the liquid pool. High efficiency TIG welding process is not sensitive to welding parameters （welding speed, welding current and electrode gap） and therefore is suitable to be applied in industry easily.