Аңдатпа
Phase transformations of stainless steels surface structure after processing by intense pulsed plasma flows was considered. The temperature gradient and melting depth of the surface of iron-based alloys under the action of high intense pulse plasma flows are calculated and comparison with experimental results was carried out. It is shown that the estimated depth of the modified layer is about 10 µm, and the characteristic size of the microstructure is 2.9 ·10−8 m. The formation of columnar crystallites and their migration to the grain boundaries of the microstructure were detected after processing of steels surface. During plasma processing, the crystal lattice of AISI 201 and AISI 321 steels is slightly distorted with a decrease in the size of the austenite crystallites. In both materials the new phase of iron nitride is formed and the size of crystallites increase in evolution of treatment process. Their minimum size is defined by the surface cooling rate. Significant changes in the formation of the main composition of the solid solution of steels occur when processing 20–40 J/cm2. Processing with 30 pulses leads to an increase in the hardness of the surface of steel AISI 321 up to 3 times.