Study on Twin-Wire CMT Welding Process and Weld Microstructure of 2205 Duplex Stainless Steel

The flux cored wire CMT welding technology was used to weld on 2205 duplex stainless steel with 5 mm thickness, and the weld morphology under different process parameters was analyzed. Based on the surfacing process, the welding parameters of front wire pulse current of 271A and rear wire cold metal transition composite pulse current of 200 A were selected for 45° and 60° groove butt welding. The results show that the weld width changes obviously with the increase of front wire current, while the weld depth and reinforcement change little, and the hardness of heat affected zone is higher than that of base metal and weld zone. There are three kinds of austenite phases in the weld area of butt welded joint, and the content of austenite is 40%-60%, which meets the welding requirements. It can be seen from the microstructure that the grain size of 60° groove is smaller than that of 45° groove.