Definition(s)
Corrosion-resistant alloys
Nonferrous-based alloys where any one or the sum of the specified amount of the elements titanium, nickel, cobalt, chromium, and molybdenum exceeds 50 % mass fraction
- NOTE: This definition is different from that in ISO 15156 (NACE MR0175/ISO 15156; see Clause 2).
Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards
Corrosion-resistant alloys (CRAs)
Alloys that are intended to be resistant to general and localized corrosion in oilfield environments that are corrosive to carbon steels. NOTE This definition is in accordance with ISO 15156-1 and is intended to include materials such as stainless steels with minimum 11,5 % mass fraction Cr, and nickel, cobalt and titanium base alloys. Other ISO documents can have other definitions.
Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards
Corrosion resistant alloy
Alloy intended to be resistant to general and localized corrosion by oilfield environments that are corrosive to carbon steels
- NOTE: This definition is in accordance with ISO 15156-1 and is intended to include materials such as stainless steel with minimum 11,5 % (mass fraction) Cr, and nickel, cobalt and titanium base alloys. Other ISO standards can have other definitions.
Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global Standards
Corrosion resistant alloy
Nonferrous-based alloy in which any one or the sum of the specified amount of the elements titanium, nickel, cobalt, chromium, and molybdenum exceeds 50 % (mass fraction) (API 6A).
Source: API TR 1PER15K-1, Protocol for Verification and Validation of High-pressure High-temperature Equipment, First Edition, March 2013. Global Standards