The effects of Mn content and solution treatment temperature on the microstructural evolution and mechanical properties of 17Cr-2Ni-0.2N-xMn duplex stainless steel were investigated by utilizing microstructural characterization and mechanical testing methods.The results indicate that while Mn,among the austenite-forming elements(Mn,Ni,N),exerts the least influence on the austenite-ferrite phase equilibrium temperature,it significantly enhances austenite stability.An increase in Mn content decreases the amount of quenched martensite and suppresses deformation-induced martensitic transformation,thereby improving the steel's ductility and toughness.Notably,with an Mn mass fraction of 3%,the steel attains a desirable balance of mechanical properties,including 35.5%elongation,944 MPa tensile strength,and 139J impact energy at room temperature.Furthermore,an appropriate alloy composition enables the formation of a nearly equiaxed dual-phase microstructure in the 17Cr type duplex stainless steel after high-temperature solution treatment.The studied 17Cr-type duplex stainless steel exhibits excellent overall mechanical properties,with a maximum tensile strength exceeding 1 200 MPa in the solution-treated state,elongation after fracture greater than 50%,an impact toughness of 204 J at room temperature,and 99 J at-10 ℃.
duplex stainless steelheat treatmentmicrostructurestability of austenitemechanical property