A study was made of the effect of temperature, upon the saturated H content and diffusion coefficient, by cathodically charging steels in solutions at various temperatures and then estimating the absorbed H by means of vacuum extraction. High-temperature diffusion coefficients were determined by monitoring the out-diffusion of H during vacuum extraction, at temperatures ranging from 250 to 550C, from steels which had been saturated at 25C. The results indicate that, at a given temperature, the lattice H was essentially independent of the steel composition.

J.F.Newman, L.L.Shreir: Corrosion Science, 1971, 11[1], 25-33

 

Table 75

Hydrogen Permeation Parameters for JBK-75 in Various Conditions

 

Treatment

Po(mol/smMPa½)

E(kJ/mol)

cold-rolled to 75% deformation

0.000427

61.77

ST (980C, 1h), WC

0.000162

56.42

ST (980C, 1h), WC, aged (740C, 4h), AC

0.001060

66.27

ST (980C, 1h), WC, aged (740C, 8h), AC

0.000390

62.00

ST (980C, 1h), WC, aged (740C, 16h), AC

0.000504

63.65

ST: solution-treated, WC: water-cooled, AC: air-cooled