SYNERGISTIC EFFECT OF NI AND FE ON SEA-WATER CORROSION OF COPPER-ALLOYS

Sea water corrosion studies on Cu-Ni-Fe alloys ranging in nickel content from 0 to 305 and iron content from less than 0. 05 to 25 have demonstrated a synergistic effect between nickel and iron in these copper alloys. This effect is apparent in corrosion data such as low velocity sea water and jet impingement tests, as well as the composition of inner corrosion product layer. Nickel is beneficial to the corrosion resistance of copper, but its effect is greatly enhanced by the presence of iron in the alloy. The reason for this effect is apparently tied to nickel enrichment of the material surface, but the mechanism of iron stimulation of nickel enrichment is undetermined at present.