Corrosion Resistance of UNS N09935 in High Pressure High Temperature Sour Environments

The AF935 alloy with a minimum yield strength of 110 ksi was successfully balloted in NACE MR0175/ISO 15156-3: 2003 based on SCC test results in a test environment much more severe than NACE Test Level V and on GHSC test results in NACE Test Level III. These results indicated a good suitability of this material for sour service applications and point out that this alloy offers economical solution to some of the conventional alloys. Further to these findings, an R&D test programme has been implemented to investigate the corrosion resistance of AF935 in more severe conditions, beyond 200 °C applications. Properties of this material and results of this test programme are herein presented and discussed.