Electron Back Scattered Diffraction Study of Dissimilar Welding Between the Super Duplex Stainless Steel and the Ni-Based Superalloy

Abstract

This research investigated the microtexture and boundaries characteristics of the Incoloy 825 Ni-based superalloy/UNS S32750 super duplex stainless steel (SDSS) dissimilar welds using electron back scattered diffraction analysis. The results indicated that the weld metal was textured; thus, {293}<311> and {348}<583> texture components were observed. As a result of the grain growth and the changes in the morphologies of the phases in the heat affected zones (HAZs), the primary texture components of the alloys were replaced by the new components. In addition, the maximum texture intensities of the generated components in the HAZs were higher than those of the related base metals. The grain growth as well as the changes in the phase morphologies also resulted in a decrease in the proportion of coincident site lattice (CSL) boundaries in the HAZs, in comparison with the base metals. Absence of CSL boundaries in the weld metal was observed too.