Technical note: Effect of non-uniform hydrogen charging on time to failure of a linepipe steel in NACE solution

Abstract

The time to failure of tensile specimens statically loaded in NACE solution (5%NaCl with O·5%CH₃COOH saturated with H₂S) is often used to characterize materials performance in sour oil or gas environments. However, there has been some concern that the distribution of absorbed hydrogen atoms in these fully immersed (and hence uniformly charged) tensile specimens may be significantly different from that in actual pipelines because, in the latter, hydrogen charging is from one surface (the inner) only. Consequently, prediction of service behaviour from laboratory tests employing full immersion may be uncertain.