Cryogenic and high temperature tensile properties of 316L steel additively manufactured by laser powder bed fusion

Abstract

316L stainless steel has many industry applications due to its excellent corrosion and oxidation resistance. Laser powder bed fusion (LPBF), a metal additive manufacturing process, is used to fabricate 316L in the current work. Epitaxial grains can be observed in as-built material. LPBF-processed 316L demonstrates both high strength and ductility at room temperature. The yield strength is 609 MPa; the UTS is 722 MPa; the elongation is 62%; LPBF-processed 316L fractured high −196 °C shows an increased strength with good ductility due to transformation induced plasticity (TRIP) and twinning-induced plasticity (TWIP). The yield strength is 818 MPa; the UTS is 1349 MPa; the elongation is 39%. The formation of deformation twinning is significantly retarded when the testing temperature reached 200 °C. At 550 °C and 600 °C, tensile curves with serrated flow were observed which is associated with dynamic strain aging (DSA). Further increasing the testing temperature to 800 °C, the yield strength was decreased to 230 MPa and the UTS was decreased to 239 MPa with an elongation of 29%. Dynamic recrystallization was observed. The short elongation obtained at 800 °C was a result of the occurrence of high temperature creep.