The effect of deformation temperature in metastable austenite zone on microstructure evolution, mechanical and corrosion properties of high Cr ferritic-martensitic steel

This work investigated the impact of deformation temperature in metastable austenite zone on microstructure evolution and mechanical and corrosion properties of high Cr ferriticmartensitic steel. The martensitic lath characteristics and the size and distribution of precipitates of the steels were observed using transmission electron microscopy (TEM). The results show that narrowing of the lath width occurs as the deformation temperature reduces from 800 to 600 degrees C. During subsequent high-temperature tempering, the martensitic lath recovery degree of the tempered steel gradually increases, and the size of the precipitates gradually decreases with the decrease of the previous deformation temperature. A tensile test was conducted on the steels subjected to high-temperature tempering. The tensile strength of deformed steel is found to be higher than that of undeformed steel. The tensile properties of the deformed steels decrease with the decrease of the deformation temperature. The electrochemical polarization curve confirms that the corrosion resistance of the deformed steel subjected to tempering is gradually improved with decreasing deformation temperature. This work clarifies the influence mechanism of deformation temperature on the microstructure and properties of high Cr ferritic-martensitic steel and provides a reliable basis for actual industrial production.