An influence of casting thickness and heat treatment regimes on structure and wearing properties of MChKh15 cast iron is investigated. The properly chosen heat treatment enables to decrease at a maximum a level of residual tensile stresses in the transition zone. The latter is being displaced into inner less stressed sections. Quenching process is described that provides the maximum degree of fixation of carbide phase in matrix. Precipitation of secondary carbides in martensite as well as formation of pearlite products of decomposition under cooling aid lowering in the maximum residual stresses in castings.