The mechanism of change in the phase composition of austenitic steels, their wear resistance and microstructure is analysed. The influence of Mn, the rate of cooling of the metal in the casting mould, and special modes of heat treatment on the physical and mechanical properties of high-manganese steels is investigated. In the studied steels, the Mn content is varied at the levels of 8%, 10%, and 13%. The content of other components of the main chemical composition is maintained within the standard for the 110Г13Л steel. Studies are conducted on cast samples of various thicknesses to control the rate of heat removal during primary crystallization. In steels with reduced Mn content, grinding of austenite grains is possible, and a significant increase in metal properties with a considerably shorter annealing duration (than this is required for the 110Г13Л steel) is shown. In thick-walled castings made of the 110Г10Л steel, the duration of annealing can be reduced by half. In castings made of the 110Г8Л steel, recrystallization can be carried out without preliminary annealing, if slow cooling is ensured during hardening of the castings in the mould. Rational modes of heat treatment of steels with a reduced Mn content are proposed providing both a significant grinding of austenite grains and increasing the complex of physical, mechanical, and operational properties of the metal.