Abstract：Abstract：AC CMT was used to weld 3mm thick austenitic stainless steel plate. The effects of different welding parameters on the structure and properties of welded joints were studied. According to the microstructural characteristics of the welded joints, they are divided into fusion zone, fusion line zone, heat affected zone and base metal. The results show that the weld surface is well formed without spatter and penetration defects.There are fine ferrite dendrites in the weld zone, columnar crystal formation near the fusion zone, austenite grain recovery and recrystallization in the heat-affected zone, and grain growth. The hardness value presents a "w" shape distribution, the lowest hardness of the heat-affected zone is 164HV, and the highest hardness of the weld zone is 186HV. With the increase of current, the yield strength and elongation increase first and then decrease. With the increase of welding speed, the tensile strength and elongation increase first and then decrease. The optimum welding parameters are: welding current 120A, welding speed 80mm/min.
2019, Vol. 38 