Structure, Phase Composition, and Mechanical Properties of an Fe–20Cr–1.5V–1.5Zr Alloy Subjected to High-Temperature Nitriding

Comprehensive studies of the structure, phase composition, and mechanical properties of the corrosion resistant Fe–20Cr–1.5V–1.5Zr alloy subjected to high-temperature nitriding and subsequent tempering are performed at temperatures of 23 and 700°C. The structure of the nitrided alloy contains a mixture of the α and γ phases and (Cr,V)2N and (Cr,V)ZrN nitride particles. Tempering performed after nitriding leads to the decomposition of the γ phase and the additional precipitation of chromium nitrides. As a result of nitriding and subsequent tempering, an increase in the static strength of a 0.5-mm-thick sheet by 1.8–2.0 times is achieved at both 23 and 700°C in the case of a ductile or quasi-ductile fracture mechanism.