Alteration in hydrogen absorption by and hydrogen permeation through a high-strength low-alloy steel due to plasma source ion implantation of nitrogen

Plasma source ion implantation of nitrogen on a high-strength steel substrate carried out at relatively low temperatures produced no discernible nitrides. The hardness increase caused by these treatments was discernible. There was indirect evidence of nitrogen in solid solution. The plasma treatments produced changes in the hydrogen permeation through the substrate as a result of alteration in the subsurface hydrogen solubility as well as the hydrogen diffusivity. The alteration in hydrogen permeation behavior depended on the time and temperature of plasma treatment.