High-temperature X-ray diffraction study of phase transformations in nitrogen-bearing steels

Abstract

The phase composition, lattice parameters, and residual stresses in the α and γ phases of steels containing 0.14–1.2 wt % N are determined by high-temperature X-ray diffraction at 20–1200°C. A procedure is proposed for the in situ quantitative study of the Cr2N nitride dissolution kinetics and austenite grain growth when diffraction patterns are taken at high temperatures. The temperature boundaries of the decomposition of the α and γ phases and the temperature of complete dissolution of nitride phases are found. The formation of interphase residual stresses during thermal treatment is considered.