Comparative assessment of electrochemical hydrogen absorption by pipeline steels with different strength

The assessment of ability to absorb hydrogen of three API grade pipeline steels: X52, X70 and X100 have been evaluated. The factors of cathodic hydrogen charging, time of exposure, and applied stress were taken into account. It has been shown that all steels demonstrate the sensitivity to hydrogenating in deoxygenated, near-neutral pH NS4 solution under relatively “soft” cathodic polarisation, although the efficiency of hydrogen permeation in metal is quite low and depends on time of exposure. Applied tensile stress, which equivalent to gross hoop stress in pipe wall under operating conditions, can accelerate the hydrogen absorption in several times. For studied steels the resistance to hydrogen absorption decreases with decreasing of steel strength.