Influence of hydrogen content in working gas on growth kinetics of hardened layer at ion nitriding of steels

摘要

The paper studies the influence of hydrogen content of 10 to 30 % in the working gas on the growth kinetics and the structure of the hardened layer at ion nitriding of martensitic, austenitic and perlitic steels. It has been found for martensitic (quenching from 930°C and tempering at 600°C) and austenitic steels that the presence of HSUB2/SUB in the amount exceeding 20% in a working chamber provokes hydrogen embrittlement of the hardened layer, which can lead to further destruction of the surface of the nitrided layer. The paper further presents some recommended values of H2 content in a working chamber for ion nitriding of these steels. It has been proven that the change in the hydrogen content within 10-30% of the working gas at ion nitriding has insignificant effect on the surface hardness and thickness of the diffusion layer in martensitic steels (quenching from 1050°C and annealing at 800°C) and perlitic steels.