Environment-assisted cracking of corrosion-resistant alloys in oil and gas production environments: A review

The environment-assisted cracking (EAC) susceptibility of corrosion-resistant alloys (CRA) used in oil and gas production is reviewed. The alloy categories are limited to martensitic stainless steels, duplex stainless steels, austenitic stainless steels, and Ni-Cr-Mo alloys. The primary focus is hydrogen sulfide (H2S)-enhanced EAC in Cl- environments at temperatures between room temperature and 232degreesC. Three EAC modes have been distinguished-hydrogen embrittlement cracking, sulfide stress cracking, and stress corrosion cracking. The environmental and metallurgical variables affecting each EAC mode are presented. Comparison is made between laboratory tests and field performance. Suggested areas of research are proposed to expand the understanding of EAC mechanisms and to improve test methods.