P. Manolatos et al., THE ELECTROCHEMICAL PERMEATION OF HYDROGEN IN STEELS WITHOUT PALLADIUM COATING .2. STUDY OF THE INFLUENCE OF MICROSTRUCTURE ON HYDROGEN DIFFUSION, Corrosion science, 37(11), 1995, pp. 1785-1796
The presence of graded microstructures such as those encountered in he
at affected zones (HAZ) may modify the material susceptibility to hydr
ogen induced cracking. In an attempt to clarify the role played by the
different microstructures present in HAZ, large simulated HAZ were pr
oduced using a Gleeble machine and studied by the hydrogen electrochem
ical permeation technique. The method was applied without palladium co
atings but the surface electrochemical conditions were strictly contro
lled. The permeation and outgassing rates are clearly related to the v
olume fraction of martensite. In ferrite-pearlite structures, the infl
uence of small AIN- and NbC-type precipitates on permeation rate was a
lso shown.