MICROSTRUCTURE AND PROPERTIES OF WELDS OF SEMI-AUSTENITIC PRECIPITATION HARDENING STAINLESS STEEL AFTER HEAT TREATMENT

摘要

This paper presents the studies of the microstructure and properties of the welded joints made of 15-7Mo precipitation hardened scmi-austenilic stainless steel welded by Tungsten Inert Gas. Microstructural changes in the heat treated welded joints was assessed. It was found that the joints of 15-7Mo steel in as welded state contain marlcnsite, auslenitc and δ-ferrite. Scanning electron microscope study of the joints was carried out. The sub-zero and destabilization heat treatment were found to decrease or completely eliminate the austenitc in the microstructure and increase hardness of the welded joint.