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 degrees C. The structure of the nitrided alloy contains a mixture of the alpha and gamma phases and (Cr,V)(2)N and (Cr,V)ZrN nitride particles. Tempering performed after nitriding leads to the decomposition of the gamma 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 degrees C in the case of a ductile or quasi-ductile fracture mechanism.