The Influence of Frictional Treatment and Low-Temperature Plasma Carburizing on the Microhardness and Electromagnetic Properties of Metastable Austenitic Steel

The microhardness and electromagnetic properties of corrosion-resistant austenitic chromium–nickel steel (16.80 wt % Cr, 8.44 wt % Ni) subjected to carburizing in electron beam plasma at temperatures of 350 and 500°C, to frictional treatment with a sliding indenter, and to that combined frictional treatment and plasma carburizing have been investigated. It has been established that plasma carburizing results in an increase in the microhardness of the steel surface from 200 to 1100 HV0.025. The total depth of hardening is 25 μm after carburizing at T = 350°C and 300 μm after carburizing at T = 500°C. Frictional treatment results in an increase in the microhardness of steel to 600 HV0.025 at a total depth of hardening of 500 μm. It has been shown that a diffusion-active layer with a dispersed structure formed after preliminary frictional treatment contributes to an additional hardening of steel to 1275 HV0.025 upon subsequent low-temperature carburizing at 350°C. The combined treatment with carburizing at a temperature of Т = 500°C results in an increase in the microhardness of steel to 820 HV0.025, and the total depth of hardening is 500 μm for both modes of combined treatment. It has also been established that plasma carburizing of studied steel results in a decrease in the readings of an eddy current device compared to quenched steel and their increase compared to steel subjected to frictional treatment, which can be used to develop techniques to control the quality of such treatments.