Metallurgical and Mechanical Behaviors of 309L-Si and ERNiCrMo-3 Dissimilar Weld on ASTM A182 F22 Steel

The present work aims to evaluate the metallurgical and mechanical behavior of dissimilar weld formed by 309L-Si and ERNiCrMo-3 (Inconel 625) electrodes combination on the ASTM A182 F22 steel with GMAW process. The welded joints were characterized by SEM, OM, tensile test and Vickers microhardness technique. The dissimilar interface formed in buttery of 309L and INC625 showed partially mixed zone (PMZ) formation and solidification microcracks that affected the mechanical properties in welded joint, presenting a fragile behavior. The F22 and INC625 interface presented high hardness regions with peaks greater than 400 HV. These regions were enriched by carbon due to the diffusion from F22 steel into the weld metal caused by tension relief heat treatment (TRHT).

Keywords:
Macrosegregation; Decarburization; Solidification microcracks