Influence of hydrogen on the tensile behaviour of a plasma ion nitrided low alloyed steel

Hydrogen embrittlement is more effective for high strength steels than for low strength ones. We examined here the effect of hydrogen contamination in a steel superficially hardened by ion nitriding. By means of tension tests performed on the nitrided and on the as received material, we attempted to describe the plastic behaviour by means of a power law with several differ ent exponants. The introduction of a brittleness factor allowed us to discu ss the hydrogen effect on the whole plastic domain.