Research on A-TIG spot welding of stainless steel

Conventional TIG welding is known as its low productivity and limited weld depth in a welding spot.Activating TIG welding(A-TIG) can greatly improve the weld penetration and thus enhance the process efficiency in comparison with the conventional TIG welding.Based on A-TIG spot welding tests for stainless steel sheets of SUS304,under the different experimental conditions,the effect of TiO2 and SiO2 used as activating flux on the properties of welding point is revealed.SiO2 increased the weld penetration dramatically while TiO2 has little effect.The weld D/W ratio due to addition of SiO2 became 0.78.The effect of flux SiO2 on the weld tensile strength is the best,while the the grains of fusion area are refined.The results show that the qualified joint weld is obtained by the A-TIG spot welding method which can meet the requirements of smoothness,nugget dimension and mechanical properties.