NACE MR0175/ISO 15156
Definition
The international standard for materials selection and qualification for sour oil-and-gas service. Sets hardness limits, alloy restrictions, and testing requirements to prevent SSC and related sulfide-assisted cracking.
Related terms
- Hydrogen-assisted cracking (HAC)
- The general term for crack initiation and propagation facilitated by absorbed atomic hydrogen. Encompasses hydrogen embrittlement, sulfide stress cracking, and hydrogen-induced cracking.
- Hydrogen embrittlement (HE)
- Loss of toughness and ductility in a metal due to absorbed atomic hydrogen, resulting in brittle fracture at stress intensities below the...
- Hydrogen-induced cracking (HIC)
- Planar crack arrays that form parallel to the steel rolling direction when high levels of hydrogen are absorbed. Common in pipeline steels...
- Liquid-metal embrittlement (LME)
- Brittle fracture of a normally ductile metal when it is in contact with a specific liquid metal. Not hydrogen-related but mechanistically analogous:...
- Sulfide stress cracking (SSC)
- Hydrogen-assisted cracking specific to H2S-containing environments. Sulfide ions poison the recombination reaction at the steel surface, forcing more atomic hydrogen to enter...
Explained in
- Hydrogen Embrittlement and Environmental CrackingThe international standard for materials selection and qualification for sour oil-and-gas service. Sets hardness limits, alloy restrictions, and testing requir...