Influence of nitrogen on structure and mechanical property of SAF2205 duplex stainless steel

The effect on the structure and mechanical property of SAF2205 duplex stainless steel were studied by increasing the nitrogen mass fraction and reducing the nickel mass fraction. The results showed that after increasing the nitrogen mass fraction and reducing the nickel mass fraction, the Austenite phase of trial steel was enlarged when the nitrogen mass fraction and nickel mass fraction were in the suitable range, and the Austenite crystal grains became smaller and homogeneous. With the decrease of the nickel mass fraction, the Austenite crystal grains became thicker and bigger, while the impact absorbing energy and intensity were both improved, and AkV was increased from 199.7 to 232.5 J, Rm and Rp0.2 were increased from 538 to 787 MPa and from 484 to 692 MPa, respectiviely, which indicated that the plastic index of steel had a slight decrease.