Slow strain rate testing of solution-annealed (s _0.2 = 552 MPa, 80 ksi) and cold-worked 22 Cr (s _0.2 = 1068 MPa, 155 ksi) duplex stainless steels (DSS) has been conducted at different hydrogen charging currents in acid-brine solutions at 80° C. The charging currents and environments were designed to simulate coupling of duplex stainless steel tubulars to carbon steel casing assuming a leak of production fluid into the annulus. To provide a framework for evaluating the results, hydrogen permeation measurements were conducted under equivalent conditions and hydrogen uptake determined.

From the latter tests, it was demonstrated that under cathodic charging conditions an effect of H₂S on hydrogen uptake was observed only above a critical charging current density, consistent with H₂S acting as a hydrogen recombination poison. Additionally, hydrogen uptake in solutions containing about 1 ppm H₂S was equivalent to that for saturated H₂S implying that sour service conditions may prevail even at very low levels of H₂S for galvanically coupled DSS.

No significant reduction in the strain-to-failure relative to oil was observed for solution-annealed DSS in H₂S-free environments at any value of the charging current density. Pre-exposure for 50 days resulted in only a modest effect decrease in the relative strain-to-failure. In H₂S-saturated environments, cracking occurred at coupling currents as low as 20 m A cm^-2. The resistance to cracking did not correlate simply with hydrogen uptake measurements suggesting that enhanced hydrogen uptake due to film rupture during slow strain rate testing may be significant.

In H₂S-saturated environments, the cold-worked material was less resistant to cracking than the solution-annealed material for a given charging current density. Failure of the cold-worked material occurred under freely corroding conditions and was associated with pitting.