The Development Of Effective Activating Agent For Stainless Steel A-TIG Welding And The Effect Of Agent On Properties Of Welding Joint

TIG welding is promising which is contributed by its high welding quality and automating the welding process conveniently. But its application is restricted by its low penetration in a single weld and low productivity. A-TIG technology was developed to overcome common TIG welding's shortcoming noted above. It is able to improve penetration drastically.On the base of referencing native and foreign works, the paper selects the compositions of activating agent for 1Crl8Ni9Ti austenitic stainless steel by numerous works. The appropriate ratio of compositions is gotten and effective activating agent is developed by the method of cross-experiment. The effect of welding parameters such as welding current, welding velocity and welding voltage on A-TIG weld's depth and width has been studied. And the effect of activating agent on weld's resistance ability to nod corruption, mechanical properties, microstructure and chemical element has also been studied.The experimental results show that both halides such as CaF2, KC1, NaF etc and oxides such as TiO2, Cr2O3 etc can constrict the welding arc and improve the depth of penetration. The ingredients of agent Y developed by cross-experience are NaF(15%)-TiO2(17%)-Cr2O3(13%)-CaF2 + Fe2O3 + ferromanganese(55%). A-TIG welding with agent Y can penetrate thorough 8mm thickness of stainless butt steel without sloping and filler by using the activating agent. At the same welding parameters, the penetration of A-TIG welding is two times more than the one of common TIG welding. The penetration of A-TIG welding is much more higher than common TIG welding. The penetration of A-TIG welding increase with the increment of welding current and the reduction of welding velocity and welding voltage. The activating agent has little effect on the 1Crl8Ni9Ti stainless steelwelds' resistance ability to nod corruption. The weld hardness, tensile strength of are increased and the weld tensility, constriction ratio are decreased slightly by activating agent. The microstructure of weld made with flux does not change significantly. The welds of TIG and A-TIG welding are both made of austenite and little ferrite. The chemical composition of weld is not changed significantly by agent.