Influence of Filler Metal and Current on Microstructure and Properties of 0Cr18Ni9/Q235 Dissimilar Welded Joints

The Tungsten Inert Gas(TIG) welding process was used to weld 0Cr18Ni9 austenitic stainless steel and Q235 carbon steel with ER309 and Ni317 wires of 2.0 mm in diameter.The microstructure,tensile properties and micro-hardness of the welded joint were studied.The results show that when the applied welding current ranges from 90 A to 120 A,the tensile strength increases with the increase of welding current,and dimples appear on the tensile fracture surface,which is typical of tough fracture.The tensile properties of the joints with ER309 welding wire are better than those with Ni317 welding wire.For both of welding wires,maximum hardness of the joints achieves at the 110 A of applied current.