Experiments were performed by using electrochemical methods, and steel membranes which were subjected to various stresses. In one series of tests, the stress was kept constant and 2 successive permeations were conducted (table 68). In a second series, an increasing stress was applied during the stationary stage of preliminary permeation. Anomalies of various types were encountered: these were a decreasing diffusion coefficient during the first permeation in the first series of experiments (table 69), and an abnormal decrease in the exit flux after dynamic loading in the second series. It was shown that they could be quantitatively interpreted in terms of an irreversible trapping which was induced by plastic deformation.

Experimental and Numerical Study of Diffusion and Trapping of Hydrogen in Plastically Deformed A508.Cl.3 Steel at Room Temperature. J.B.Leblond, D.Nejem, D.Dubois, S.Talbot-Besnard: Acta Metallurgica, 1987, 35[7], 1703-14

Table 70

Diffusivity of H in Fe-Mo at 300 to 800C