Evolution of the structure and properties of AISI 1020 steel subjected to elion nitriding in a low-pressure gas discharge plasma

A method and experiments of nitriding AISI 1020 steel with simultaneous heating of the samples with the electron component of plasma are described. A nitriding regime is explained that makes it possible to form a hardened layer up to 500 µm thick. It is shown that the microhardness of the surface layer of the steel increases with the increase in the nitriding temperature and correlates with the relative content of the nitride phase. It has found that in the nitriding temperature range from 450 °C to 600 °C, the maximum microhardness is formed in the near-surface layer at the depth of ~10 µm at 520 °C. It has been established that the steel wear resistance is determined by the concentration of nitrogen atoms in the α-Fe crystal lattice. It has been shown that micropores formed in the surface layer of the steel nitrided at 520 °C contribute to an increase in material wear under dry friction.