A Review of Materials Application Limits in NORSOK M-001 and ISO 21457

In order to become more cost efficient, the Norwegian authorities initiated in the early 1990s a standardization project for the upstream oil and gas industry. One of the important products from the project was the NORSOK M-001 standard which addresses the material selection for offshore production facilities. A new international standard—ISO 21457—based on the same principles as NORSOK M-001 was published in 2010 and the latest version of NORSOK M-001 only gives clarifications to the international standard. ISO 21457 adopted important user limits from NORSOK M-001 for materials in selected service conditions and some new limits were defined. Examples of limits for corrosion resistant alloys are maximum operating temperatures to avoid stress corrosion cracking in marine atmosphere, maximum operation temperature for seawater service, and utilization limits in order to prevent hydrogen-induced stress cracking from cathodic protection. These limits are based on a combination of field experience and laboratory testing, and the industry must incorporate a certain conservatism in order to operate safely. The technical justification for the limits are presented and discussed.