What is NACE MR0175 definition of a Corrosion Resistant Alloy (CRA)?
I need your help with the definition of CRAs in Part 3 of MR0175/ISO 15156. The “corrosion-resistant alloys” is very general and does not specify whether or not the definition includes the Fe-based alloys or not. More than that, the term CRA is used together with “other alloys” making it even more confusing.
NACE MR0175/ISO 15156-1, Paragraph 3.6 contains a definition of “corrosion-resistant alloy” (CRA). It reads: “alloy intended to be resistant to general and localized corrosion of oilfield environments that are corrosive to carbon steel.” This is taken from EFC 17.
“Other Alloys” are those not covered by the definitions of carbon steel or CRA. For example, copper is not considered resistant to general corrosion but is considered in NACE MR0175/ISO 15156-3.
This question is in relation to NACE MR0175/ISO 15156-1 Clause 3
Reference: ISO 15156 Maintenance Panel Inquiry #2004-12