Microstructural and Mechanical Behavior Studies of Dissimilar Weld on TIG Welding

Abstract

In this study, the microstructural and mechanical behavior studies of austenitic stainless steel dissimilar weld were investigated. Dissimilar material combinations are involved in the subsystem of liquid rocket engines. Since most of these components are fabricated through metal joining route, the HAZ’s of weld is critical. The present work deals with the dissimilar metal welding of grades AISI 321 with AISI 316L by selecting suitable solid solution filler metal. The main objective of the present work is to observe HAZ of the dissimilar weld. In the present study, mechanical properties were evaluated at room and cryogenic temperature since this dissimilar combination was also exposed to the cryogenic fluid. Microstructural observations showed cast dendritic structure in the fusion zone. However, heat-affected zone of AISI316L showed ferrite and few bands could be sensitized band along grain boundaries. Since the dissimilar combination was involved, microhardness survey was carried out.