Depending on the process conditions, corrosion by CO2 and H2S, chloride-induced localised pitting or crevice corrosion, stress corrosion cracking and/or H2-induced sulphide stress cracking may be encountered by metallic materials used for tubing and piping in oil and gas field service. Alloy 31 (UNS NO8031) is a high alloyed stainless steel containing 3 1 % Ni, 27 % Cr and 6 % Mo. Its high resistance to localised corrosion in both acid solutions of chlorides and in seawater suggested that it may be a candidate material for service in the oil and gas industry. The composition of alloy 31 in comparison to that of other alloys used in oil & gas production is shown in Table 1. To check the potential of alloy 31 for oil and gas applications, a wide variety of corrosion tests comprising tests in natural seawater and in various chloride-containing solutions, slow strain rate tests, and SSC-tests according to NACE NW0175 both in the cold-worked and in the solution-annealed condition have been carried out. All results show that alloy 31 has high resistance to pitting and crevice corrosion in chloride bearing media due to its high chromium and molybdenum content. It was found that alloy 31 is not sensitive to stress corrosion cracking. Alloy 31 was tested in the cold-worked condition (HRC < 35) for sour gas applications according to NACE MR0175 and has been approved up to LEVEL VI.
Chloride and sulphide stress corrosion cracking of alloy 31 - UNS NO8031
2000
3 Seiten, 5 Tabellen
Aufsatz (Konferenz)
Datenträger
Englisch
Internal corrosion offshore pipelines. Sulphide stress corrosion
Tema Archiv | 1983
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