Conclusions
The ability to absorb electrochemical hydrogen by welded pipeline steel API X52 has been studied and the
received results have led to the following conclusions. The weldment components of the given steel demonstrate the
sensitivity to hydrogenating in deoxygenated, near-neutral pH NS4 solution under cathodic polarisation that is
close to the situation of freely corroding system. In general, the efficiency of hydrogen permeation metal is
relatively low for all components of weld and after achieving of some early maximum there is the tendency of
monotonic decreasing of parameter with exposure time. 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. Presented study reflects the hydrogenating conditions, which simulate of
real operating pipelines and therefore the received values of parameters may be used as reference data for
assessment of hydrogenating of weld components during long-term operation of the considered pipelines.