Microstructure and mechanical properties of deposited metal of gas shielded flux-cored wire under different welding currents

The microstructure and mechanical properties of deposited metal under different welding currents were studied for a gas shielded flux-cored wire for X80 pipeline steel. The results show that the microstructure of deposited metal was mainly composed of acicular ferrite, massive ferrite and granular bainite. When the welding current were 150-250 A, with the increase of welding current, the grain size of the microstructure increased, the yield strength, tensile strength and impact property of the deposited metal increased first and then decreased. When the welding current was 200 A, the mechanical properties of the deposited metal reached the maximum, and the microstructure of the weld was mainly fine ferrite.