Corrosion of Copper--Zinc and Copper--Nickel Alloys in a Geothermal Brine

摘要

The rationale for using materials selection rather than chemical inhibition for corrosion control is discussed. The geothermal environment used for the tests is described. General corrosion caused the majority of the weight loss in the copper and the copper--zinc alloys. Localized corrosion was the principal mode of attack in the copper--nickel alloys. Our tests show trends towards higher corrosion rates with increasing copper content for both copper--zinc and copper--nickel alloys. The copper--nickel alloys have corrosion rates about six times those of brasses of similar copper content. Commercially pure copper has a corrosion rate 20 to 30% of the rate suggested by trends in the data for the brasses. Sulfides appear to be the major aggressive species for the materials studied. Sulfide corrosion products retained on the surfaces of the samples usually provided some protection to the substrate metal. (ERA citation 04:042804)