Sulphide stress cracking
From Biocrawler, the free encyclopedia.
Sulphide stress cracking (SSC), or sulphide stress corrosion cracking (SSCC), is a special corrosion type, a form of stress corrosion cracking. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and elementary hydrogen, which gets absorbed in metal and leads to hydrogen embrittlement. High content of nickel in the steels greatly improves their resistance to SSC. This type of corrosion is worst at temperatures around 80°C (176 F).
Sulphide stress cracking has special importance in gas and oil industry, as the materials being processed there (natural gas and crude oil) often contain considerable amount of hydrogen sulfide. Equipment that comes in contact with such high-sulphur materials has to be rated for sour service.
