HEAT TREATMENT OF POWDER METALLURGY CONSTRUCTIONAL STEEL (REVIEW).

This review of powder metallurgy steels covers the period 1960 to date. Some general conclusions are drawn. While following the general rules, the transformations in heating and cooling of a sintered steel have their own specific features caused by the presence of porosity, structural inhomogeneity, and inhomogeneity of the solid solution. The porosity and increased microdefect content have an influence on the position of the critical points, the austenitization process, and the transformations of supercooled austenite. The inhomogeneity of the solid solution formed in sintering alloy cermet steels also changes the position of the critical points therefore in selection of the heat treat cycles, it is necessary to determine the critical points in each individual case.