Structural-Phase Composition and Hardness of Steel of the Fe–Cr–Mn–Mo–Al–Mg–N–C System Obtained by the Method of Self-Propagating High-Temperature Synthesis Under Nitrogen Pressure

The possibility of obtaining solid ingots (without gas porosity) of steel of the Fe–Cr–Mn–Mo–Al–Mg– N–C system by the method of self-propagating high-temperature synthesis under nitrogen pressure is demonstrated. The structure of an ingot consists of a high nitrogen austenitic matrix; within which dispersed reinforcing inclusions are evenly distributed throughout the volume. These inclusions are conglomerates in the center of which magnesium oxide is concentrated with impurities of aluminum oxide, and around which aluminum nitride is located. The structural and phase composition of this steel is studied in a cast condition and after heat treatment at 1250°C for 2 hours followed by water quenching. A reduction in specimen hardness after homogenizing heat treatment is revealed: from 389 HV to 271 HV . In this case matrix microhardness in a heat-treated specimen is 40 HV lower than the overall hardness of a specimen. This demonstrates the reinforcing effect of uniformly distributed dispersed inclusions detected.