Evaluation of Electrochemical Hydrogen Absorption in Welded Pipe

The assessment of ability to absorb hydrogen by welds components of API grade pipeline steel X52 has been done. The factors of cathodic hydrogen charging, time of exposure on hydrogen concentration in base metal, heat affected zone and metal of weld were taken into account. It has been shown that all components of weld 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 relatively low and depends on time of exposure. The ability to absorb hydrogen decreases in the following sequence: heat affected zone – base metal – weld. The sensitivity to hydrogenation is higher for heat affected zone in comparison with base metal and weld.