Corrosion Performance of Alloy 29 in Simulated Sour Environments

In order to evaluate the corrosion resistance of Alloy 29 material in sour environments, laboratory testing has been conducted using tensile test specimens. Testing was performed in accordance with NACE TM0177 Method A, modified for autoclave testing at high pressures and temperatures. The testing was performed at various temperatures, partial pressures of H₂S and chloride concentrations of the brine. Considerably higher chloride concentration and partial pressure of H₂S were used than what has previously been reported for this material. The tests were carried out both with and without elemental sulfur added to the brine. The results presented in this study suggest that the existing limits of 4c materials in the NACE standard MR0175/ ISO 15156 are too conservative for Alloy 29.