不锈钢高频复合双钨极氩弧焊接工艺方法

针对双钨极TIG焊存在的电弧压力小、焊缝熔深浅等问题，提出了一种新型焊接工艺方法——高频复合双钨极TIG焊(high frequency hybrid twin-electrode TIG welding, HFHT-TIG焊)，在双钨极氩弧焊的一个钨极上通以高频脉冲电流，达到提高电弧压力和挺度、搅拌熔池、细化晶粒、改善接头组织和力学性能的目的. 采用HFHT-TIG焊进行了6 mm厚奥氏体不锈钢焊接工艺试验，并与双钨极TIG焊接头进行对比. 结果表明，HFHT-TIG焊能够显著提高电弧挺度和电弧压力，焊缝表面成形更佳，横截面对称性更好，焊缝区的树枝晶组织更加细小，断口韧窝更加均匀和细密，接头的抗拉强度和断后伸长率分别提高了12.1%和30.2%.

High frequency hybrid twin-electrode TIG welding process for stainless steel

In order to solve the problems of small arc pressure and depth of weld in twin-electrode TIG welding, a new type gas tungsten arc welding process of high frequency hybrid twin-electrode TIG welding (HFHT-TIG) was put forward. A high frequency pulse current was added on one tungsten electrode of twin-electrode TIG welding to achieve the purpose of improving the arc pressure and stiffness, stirring the molten pool, refining the grains, improving the microstructure and mechanical properties of the joint. The 6 mm thick austenitic stainless steel welding process test was carried out by HFHT-TIG welding and compared with twin-electrode TIG welding. The results show that HFHT-TIG could significantly increase the arc stiffness and pressure. The surface forming and cross-section symmetry of the weld was better. The microstructure of the weld was tinier. The dimples in the fracture were more uniform and fine. The joint tensile strength and break elongation increased by 12.1% and 30.2%, respectively.