Microstructural Study of Metal Arc Welded Austenitic Stainless Steel for Automotive and Nuclear Applications

In the present investigation, tensile, impact, microhardness properties and metallurgical behaviour of Manual Metal Arc Welded (MMAW) 316LN Stainless Steel (SS) were analysed and discussed. From this investigation, it was observed that the optical micrograph of the weld metal region solidified in a fully austenitic mode along with small volume fractions of δ-ferrite. The existence of δ-ferrite enhances the strength but reduces ductility and toughness. The microhardness of the weld metal region is higher than others. The tensile properties are superior to 316LN SS and the failure of the transverse tensile specimens was found at the base metal region. The fracture surfaces of both impact toughness and tensile specimens have shallow dimples and flat facets.