EFFECT OF FILLER METALS ON THE MECHANICAL PROPERTIES OF DISSIMILAR WELDING OF STAINLESS STEEL 316L AND CARBON STEEL A516 GR 70

Abstract

This paper describes an investigation on the effect of using three different filler metals to weld two dissimilar metals namely, stainless steel 316L and low alloy carbon steel A516 gr 70. Manual Gas Tungsten Arc welding (GTAW) with three filler metals including ER 80S-Ni1, ER309L, ER NiCrMo-3 were selected to weld the two metals. Radiography and penetrant tests were performed on the welded metals to ensure the surface and internal soundness of the welds based on the tensile tests results, all the specimens failed at the carbon steel A516 gr 70 base metals with fully ductile fracture mode (cup and cone). Welded samples using Inconel 615 filler metal has the highest strength of 512 MPa while other samples show almost similar strength of 481 and 487 MPa. The tensile strength of all the welded samples is found to be in between the tensile strength of the base metals. Micro-hardness test showed that ER80S-Ni1weld has the highest hardness, meanwhile hardness profile of ER309L presented a sharp drop in the stainless steel side and ER NiCrMo-3 weld metal illustrated hardness above the two base metals with fewer variations across the weld metal.