Investigation of pitting corrosion of a copper tube in a heating system

Electrochemical tests, as well as surface and chemical analyses were used to examine the mechanism of pitting failure of a copper tube. Synthetic tap water simulating the hot water in a heating system and field-used heating water at 60 °C were used as electrolytes in these tests. The results showed that the presence of a Cu(I) oxide layer on the copper surface is essential for pitting corrosion of a copper tube in hot synthetic tap water. Moreover, the pitting corrosion of copper tubes is preferred in heating water containing higher concentrations of Fe species and under stagnant condition.