The challenges in characterizing susceptibility of corrosion resistant alloys (CRAs) to hydrogen embrittlement in service are highlighted using experimental data for duplex stainless steels (DSSs) in two major
industrial applications: in oil production environments downhole, where galvanic coupling to carbon steel can cause hydrogen uptake, and in subsea pipelines where cathodic protection provides the source of hydrogen atoms. The influence of environment composition, charging current, pre-exposure, time, temperature, temperature excursions, and mechanical test method is examined. For constant temperature conditions, preexposure may have no major impact on embrittlement of DSSs because hydrogen ingress via regions of mechanically ruptured oxide film is dominant, unless there are internal microstructural regions or defects of high susceptibility. Pre-exposure maybe more significant when excursions from high to low temperature occur. The application of interrupted slow strain rate testing to determination of the threshold strain to cracking of a DSS indicates a need for testing at very low strain rates. The time-consuming nature of this testing may inhibit its extended utilisation but without such data there is a measure of uncertainty in materials selection with respect to the degree of risk and the tolerance to service excursions. Keywords: duplex stainless steels, hydrogen embrittlement, galvanic coupling, cathodic protection, seawater, oil production fluids, H2S, interrupted slow strain rate testing.