<p>The article is dedicated to the study of heat treatment processes of sintered powder steels, with a&#xa0;focus on austenitization processes. The authors consider the specifics of structural transformations occurring during heating and austenitization of sintered powder steels. The study presents an analysis of the influence of chemical composition, porosity, and structural defects on the kinetics and mechanism of austenitization processes in sintered powder steels with ultrafine particles. It is shown that porosity has a&#xa0;significant effect on the heating rate, the dissolution of carbides, and the processes of austenite homogenization. The obtained data contribute to the understanding of the specifics of structural transformations during the heat treatment of sintered powder steels and can be used to optimize process conditions.</p>