Microstructure and High Temperature Deformation Behavior of Cast 310S Alloy

High temperature deformation behavior of cast 310S stainless steel has been investigated in this study by performing tensile and compression tests at temperatures from 900 to 1200C. Rectangular ingots of which the dimensions were 350×350×100 in millimeter were cast using vacuum induction melting. Phase equilibrium was calculated using the FactSage®, thermodynamic software and database. Thermal expansion coefficient was also measured on the ingot in the temperature range from room temperature to 1200C. Tensile strength of cast 310S stainless steel was 9 MPa at 1200C, which is a little higher than that of a wrought 310S. With temperature decreased, tensile strength increased rapidly and reached up to 72 MPa at 900C. Elongation also increased with temperature decreased. Microstructure observation revealed that σ phase was precipitated along the grain boundary and within the matrix over 1200C, which is detrimental to high temperature elongation. Keywords—Stainless steel, STS 310S, high temperature deformation, microstructure, mechanical properties.