The flow corrosion mechanism of copper base alloys in sea water in the presence of sulphide contamination

A relationship between mass transfer conditions for condenser tubes in service and electrochemical rotating disc electrode experiments based on mass transfer coefficients analogies is proposed. A reaction order of one has been found for the reduction of oxygen on copper base alloys, and the elementary anodic dissolution processes under flow conditions has been studied. The pollution of the sea water by sulphide results in the formation of a contaminated surface film which has better electrocatalytic properties for O 2 reduction than the cuprous oxide films formed in clean aerated sea water. In most cases, the anodic process remains unaltered and the deleterious effect of sulphide is only related to the increase of the cathodic process rate. None of the materials studied showed any significant resistance towards this pollutant, in a procedure designed to test material behaviour under variable S 2− contamination.