HYDROGEN PICKUP IN ION NITRIDED STEELS

Using the energy recoil detection analysis technique, hydrogen close t o the surface of ion nitrided AISI steel M2 was studied. A surface hyd rogen peak was observed in all samples, with or without exposure to th e glow discharge. Some bulk hydrogen was also measured in all cases; i ts distribution was dependent on the history of the sample. The effect of the glow discharge is to drive part of the surface hydrogen into t he bulk, depending on the treatment time. No obvious correlation with previously measured nitrogen profiles or microhardness profiles was fo und. (C) 1993 The Institute of Materials.