MIG Welded Dissimilar AISI 430/304L Butt Joint: Microstructure and Joint Performance

Abstract

In recent years, dissimilar welds are increasingly demanded in numerous industrial applications due to the economic advantages and superior joint performance. Thus, joining of dissimilar steels is highly demanded in various industries and production of defect-free dissimilar joints by conventional fusion welding processes is rather important. In this study, 5 mm thick AISI 430 ferritic and AISI 304L austenitic plates were joined by the gas metal arc welding in butt configuration. A detailed microstructural investigation was conducted across the weld region of the joint by optical microscopy and SEM. Micro-hardness and mechanical tests were employed to determine the mechanical properties of the joints fabricated. The welded joint exhibited a tensile strength value of about 100% of the lower strength base metal, i.e. AISI 430 BM. In contrast, the confined plasticity in the lower strength AISI 430 base metal side resulted in low ductility performance, i.e. about 57%.