Investigations on the effect of heat treatment on laser powder bed fusion built SS316L alloy

The present investigation aims at studying the changes happening in the mechanical and microstructural characteristics of additively manufactured Stainless Steel SS316L components post heat treatment. The samples printed through the Laser powder bed fusion based AM technique is considered for investigation. The samples are heat-treated at 650 °C and 1100 °C for 2 h and furnace cooled. The heat treatment is found to impart a substantial impact on the mechanical and microstructural characteristics of the component. The as-built SS316L sample possesses a micro-hardness value of 221.5HV, a tensile strength of 529 MPa, and total elongation of 28.5%. The heat treatment of samples at 1100 °C for 2 h lowers the micro hardness value (175.6HV), tensile strength (510 MPa) and increases the ductility (83.5%). The grain size, porosities and dislocation density are reduced during the heat treatment and the mechanical characteristics get modified. Hence, heat treatment can be considered as an effective method for altering the mechanical characteristics of the additively manufactured SS316L functional components.