Research on Microstructure and Properties of Welded joint of 2205 Steel with FCAW

On the basis of the analysis of composition, microstructure, properties and weldability of 2205 duplex stainless steel, the flux cored arc welding (FCAW) process is made. Then the microstructure, mechanical properties and corrosion resistance of welded joint were analyzed. The results shows using FCAW process, in order to obtain high strength, perfect impact toughness and overall and partial resistance to stress corrosion in welded joint, the Ni content of duplex stainless steel welding material should be 2% to 4% higher than that of base metal, multi-layer and multi-channel welding is adopted with the strict control of energy input less than or equal to 0.926KJ/mm, layer temperature is less than 120 degrees C, thus the appropriate proportion of two-phase structure in the welded joint can be got. Using a reasonable welding procedure, the microstructure in weld beam is austenite (A) + ferrite (F), and in heat affected zone is ferrite (F) + austenite (A) + a small amount of third phase, the content of austenite in weld beam and heat affected zone is higher than that of the base metal. Tensile strength of the welded joint is up to 854.5MPa and the fracture occurs in the base metal and the heat affected zone. The welded joint has high strength, good plasticity, toughness and corrosion resistance.