Safe Use Limits for Stainless Steels Information included here is from a multiclient sponsored research program entitled, "Safe Use Limits for Stainless Steels in Production of Oil and Gas Containing H₂S and CO₂." This program involved extensive experimental studies which were conducted to better identify the limits of environmental severity (i.e. H₂S and CO₂ partial pressure, chloride content, pH and temperature) where stainless steels may be useful in oil and gas production tubulars and equipment.

A total of twenty-one companies participated in this program. Originally, the program budget was developed based on only 15 companies. The funding received from the additional sponsors was used to expand the number of tests and alloys included in this program. The program was originally scheduled to be completed in two years. However, with the expanded scope of work, the program was extended to a total duration of 4 years. Therefore, the experimental portion of the program ran from August 1990 through January 1994. From January 1994 through May 1994, the final results were reviewed and tabulated and the draft final report prepared. Following a meeting with the sponsor representatives in May 1994, some additional data was generated and revised guidelines presented herein.

Details

• Total of 22 alloys were exposed to simulated oil field production environments containing H₂S, CO₂, chlorides and bicarbonates
• 18 environments were used to find critical pitting temperature of 78 specimens - CPT test matrix
• 160 autoclave exposure tests were performed on 86 speciments in 16 environments - ACE test matrix
• 30 slow strain rate tests were performed on 12 specimens - SSR test matrix
• Focus on the documentation of the effects of environmental and metallurgical variables on the general and localized corrosion behavior and resistance to environmental induced cracking
• Use of Critical pitting temperature (CPT), Autoclave exposure (ACE) and Slow strain rate (SSR) tests and surface chemical analyses to provide additional information.