Abstract
The process of high-temperature pulsed plasma flow interaction with the surface of steel samples is considered. The features of plasma treatment in different regimes and the changes in the structure and properties of the steel samples after plasma impact are discussed. The surface of the stainless steel samples was modified by forming nanosize columnar crystallites mainly located along the grain boundaries. The structure changes in the steels studied are associated with the formation of a new phase of iron nitride and significant microdistortions of the crystalline lattice. A metallographic analysis confirms the possible increase in the microhardness of the material after the surface treatment by a pulsed plasma. But the main reason for the hardening is the decrease in the crystallite size occurring in all types of materials.