Metallurgical and Mechanical Properties Variation Along the Thickness of Electron Beam Welded Ferritic Stainless Steel Joints After Postweld Heat Treatment

Abstract

The effect of the postweld heat treatment (550°C for 75 min) on the electron beam welded joints of AISI 409 thick plates was assessed in terms of tensile and impact performance. Through thickness, analysis was carried out by dividing the weld joint into three sections, i.e., top section, middle section, and bottom section. The results showed that the size of the grains got refined at the bottom. The heat treatment also led to reduction in the grain size. X-ray diffraction analysis showed the presence of martensite in the weld joint which reduced after heat treatment. The 532 MPa tensile strength was achieved after the heat treatment for the specimens extracted from the bottom of the welded plate. The impact toughness of the weld joint was 37% less than the base metal; however, impact toughness of 31J was achieved at the top section after postweld heat treatment.