Clarifying the Discrepancy in Temperature Limits for Super Duplex Stainless Steel Materials in Oil and Gas Production Environments

Introduction

This article seeks to clarify the discrepancy in the temperature limit for using super duplex stainless steel materials in oil and gas production environments. According to NACE MR0175/ ISO 15156, super duplex stainless steel materials can be used for temperatures up to 232°C and partial pressure of H₂S up to 3 psi with any combination of chloride concentration and in situ pH occurring in production environments. However, experimental data from API 938-C shows lower maximum temperatures of 80°C and 50°C for pitting and crevice corrosion, respectively, for super duplex stainless steel materials (Grade 2507).

Clarification of NACE MR0175/ISO 15156-3

The response clarifies that NACE MR0175/ISO 15156-3 addresses environmental cracking in the presence of H₂S and does not currently address pitting and crevice corrosion. The current values in the document are based on successful ballots and history. It is important to note that the tables state “”production environments,”” which are oxygen-free.

API Technical Report 938-C

API Technical Report 938-C focuses on the use of duplex stainless steels in the oil refining industry. Therefore, it may be necessary to employ a consultant to assist with specific application requirements. This inquiry’s reference code is MP Inquiry 2017-17.

Technical Support

The article also offers technical support in identifying the operating limits of duplex and superduplex stainless steels for specific applications.

Conclusion

In conclusion, the discrepancy in temperature limits for using super duplex stainless steel materials in oil and gas production environments can be clarified by understanding the differences between NACE MR0175/ISO 15156-3 and API Technical Report 938-C. It is important to consult with a consultant to determine specific application requirements.