Wrought CuNi30Cr2 (CNC) a New Concept for a Corrosion Resistant Copper Alloy

For many decades corrosion resistant Copper Alloys have been utilized in sea water applications for their unique combination of properties anti-biofouling non-sparking resistance to cavitation corrosion excellent wear properties and low magnetic permeability.One disadvantage has been lack of mechanical strength and Copper Nickel Chromium (CuNi30Cr2) is a unique alloy developed to overcome this. It does not rely on a precipitation hardening mechanism for increasing the mechanical properties but “spinodal” decomposition which is a chemical strengthening mechanism. Additionally the alloy is single phase and hence it does not suffer from selective phase corrosion which has been problematic with some copper based alloys in marine salt water environments.This paper evaluates the wrought version of CuNi30Cr2 which can now be manufactured to Def Stan 02-886 and offers significant scope for design engineers with much higher mechanical properties increased toughness and increased internal integrity. It provides the findings of a four year corrosion program with comparisons against 26 other alloys involving a range of copper alloys Monel® Inconel® Super Duplex Titanium and Stainless Steels. General corrosion galvanic and crevice corrosion in a sea water environment were all examined as well as mechanical properties.

Product Number: 51319-13070-SG
Author: Ivan Richardson
Publication Date: 2019