Definition(s)
Corrosion-Resistant Alloy (CRA)
Alloy intended to be resistant to general and localized corrosion and/or environmental cracking in environments that are corrosive to carbon and low-alloy steels.
Source: API SPEC 5CRA, Specification for Corrosion Resistant Alloy Seamless Tubes for Use as Casing, Tubing and Coupling Stock, Upstream Segment, First Edition, February 2010 (Errata August 2011). Global Standards
Corrosion-Resistant Alloy (CRA)
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. NOTE This definition is different from that in ISO 15156 (NACE MR0175; see Clause 2).
Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards
Corrosion-Resistant Alloy (CRA)
Non-ferrous alloy for which any one or the sum of the specified amount of the following alloy elements exceeds 50 %: titanium, nickel, cobalt, chromium and molybdenum. NOTE This term refers to corrosion-resistant alloys and not cracking-resistant alloys as mentioned in ISO 15156 (all parts).
Source: API SPEC 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment, Upstream Segment, Second Edition May 2011 (Errata September 2011). Global Standards