Comparative research on the mechanical property and precipitation of the 2101 and 2205 duplex stainless steels

TF7; The mechanical property and precipitation of the 2101 and 2205 duplex stainless steels were investigated. The results show that with nitrogen-content increasing from 0.12% to 0.26% to partly replace nickel ,the yield strength of the 2101 steel gains an increase of 80 MPa whilst its elongation proportion keeps unchanged. The impact energy at a low temperature is obviously reduced. The temperature at which the impact energy starts decreasing is lower than 20℃, -20℃ and -40℃ for the 2101 steels containing 0.5 % Ni, 1.5 % Ni and 2.5% Ni respectively, whereas it is -70℃ for the 5% Ni-containing 2205 steel. The nose temperature of precipitation is 700℃ for the 2101 steel and 850℃ for the 2205 steel. The scanning electronic microscope (SEM) ,the transmission electron microscope (TEM) and the X-ray diffraction (XRD) analyses show that the drop in the impact energy of the 2101 steel can be mainly attributed to the precipitation of Cr2N upon ageing while it is attributed to the sigma phase for the 2205 steel.