Microstructure evolution and quantitative analysis of mechanical properties of cold-rolled low carbon niobium steel

Based on the idea of "plain" of alloying elements, Fe-0.2C-2Nb (wt%) alloy steel was designed. The microstructure of the alloy was effectively controlled by means of severe plastic deformation at room temperature and reasonable heat treatment process. The microstructure evolution of the alloy was systematically characterized by TEM. After annealing at 600 degrees C for 0.5 h, the ultimate tensile strength of the sample reached 844 MPa, the total elongation reached 13%, which had an equilibrium state of mechanical properties. Thus a quantitative model between the microstructure parameters and mechanical properties was established to reveal the deformation mechanism and strengthening mechanism of the alloy.