Effect of conventional and alternative solution and stabilizing heat treatment on the microstructure of a 347 stainless steel welded joint

AbstractThis work studies the microstructure formed in the heat-affected zone (HAZ) and in the melting zone (MZ) of a joint welded by the automatic TIG process in the root pass, plasma process in the filler passes and SAW for the final passes in a butt joints with a single-V groove using AISI 347 austenitic stainless steel. The following conditions are studied: as-welded; after conventional solution heat treatment at 1060 °C and stabilizing treatment at 900 °C; and after alternative heat treatment, in which the workpiece underwent solution heat treatment at 1060 °C and was held in the furnace, which was cooled to 900 °C for stabilizing. The results show that, in the as-welded condition, there was grain growth in the HAZ, and the MZ had 13% of δ ferrite with various morphologies, observing precipitation of Cr and Nb carbides. After conventional solution and stabilizing heat treatment, a significant decrease was observed in the content of δ ferrite in the HAZ and in the MZ, observing Nb and Cr carbides, dis...