What is a Corrosion-Resistant Alloy (CRA)?

This page offers a question and answer related to the definition of “”corrosion-resistant alloy”” (CRA) in Part 3 of MR0175/ISO 15156.

The Question:

What is the definition of CRAs, does it include Fe-based alloys, and how does it relate to “”other alloys”” mentioned in the standard?

The Answer:

According to NACE MR0175/ISO 15156-1, Paragraph 3.6, CRAs are alloys intended to resist general and localized corrosion in oilfield environments that are corrosive to carbon steel. “”Other Alloys”” refer to those not covered by the definitions of carbon steel or CRA. For example, copper is not considered resistant to general corrosion but is still considered in NACE MR0175/ISO 15156-3.

This question relates to NACE MR0175/ISO 15156-3, and the reference cited is ISO 15156 Maintenance Panel Inquiry #2004-12.