The effects of pH

temperature and H2S concentration on hydrogen permeation current and corrosion rate of Q235A carbon steel in weakly acidic medium were studied with the potentiostatic anodic polarization and mass loss methods. The relationship between hydrogen permeation current density and corrosion rate was investigated

aiming at using the hydrogen flux method in online non-intrusive corrosion monitoring of oil pipelines. Increasing acidity and temperature could boost hydrogen permeation current and corrosion rate of Q235A steel in the corrosive solutions

with a good linear relationship between them. The corrosion rate of Q235A steel increased initially and then decreased slightly with increasing concentration of H2S. Meanwhile

hydrogen permeation current also increased at first and then stabilized. When the concentration of H2S was 5-200 mg·L-1

there was a quadratic function between corrosion rate and hydrogen permeation current. Based on inner corrosion monitoring of an experimental pipe by a self-made hydrogenermeation flux probe

the thick pipe wall could decrease the sensitivity of hydrogen permeation current. However

by the help of step potentiostatic polarization

hydrogen permeation flux was found to be linearly related to the corrosion rate of Q235A steel measured by mass loss

indicating that the hydrogen permeation flux could be applicable for the non-intrusive inner corrosion monitoring of thick oil pipelines.