THE EFFECT OF PRIOR MECHANICAL DEFORMATION ON HYDROGEN TRANSPORT THROUGH 13-PERCENT CHROMIUM MARTENSITIC STAINLESS-STEEL

Hydrogen permeation measurements have been made on a 13% chromium martensitic stainless steel which had been previously mechanically deformed. Tensile deformation was applied up to strains of 8%, corresponding to the UTS, and cold rolling was used to generate higher levels of deformation up to 50%. Analysis of the permeation transients for strains below UTS has shown a small but significant increase in the number of reversible trap sites, which is consistent with their association with dislocations. There was little change in the number of irreversible trap sites by virtue of maintaining the strain below the level at which significant interfacial separation could occur. The results of this study confirm that the major reversible trap sites in this steel are associated with dislocations.