Effect of heat input on microstructure and mechanical properties in gas metal arc welding of ferritic stainless steel

Abstract

The variation of heat input on microstructure and mechanical properties in gas metal arc welding of ferritic stainless steel (grade 409 L) using two different austenitic filler wires ER304 L and ER308 L have been discussed in this work. Three different heat input parameters of 0.3, 0.4 and 0.5 kJ mm-1 are used in this experimental work and the effect of heat input on the properties of weldment were investigated using metallographic study and mechanical testing. Percentage dilution, chromium nickel ratio, microstructure, microhardness and tensile properties were all found to be affected by the heat input. It was observed that welded sample with heat input of 0.4 kJ mm-1 possesses superior mechanical properties irrespective of type of filler wire used. Mechanical properties obtained by using 304 L filler wire were found to be better than those obtained using 308 L filler wire, irrespective of heat input provided during welding. © 2018 IOP Publishing Ltd.