Effect of stress on the diffusion of electrochemically produced hydrogen in steel

Abstract

1. Elastic strains activate hydrogen diffusion through a steel membrane. 2. Intense hydrogen charging leads to an increase in hydrogen collector size and to local plastic deformation of the metal in the vicinity of the collectors. The reduction in hydrogen permeability of steel under these conditions is attributable to a reduction in the permeable cross-section of the metal and to an increase in hydrogen concentration in regions of high stress concentration around the collectors. 3. General plastic deformation of steel causes a sharp reduction in its hydrogen permeability owing to the formation of a large number of structural defects which act as stress raisers and internal hydrogen collectors.