純水中における銅及び隣接するステンレス鋼の腐食

抄録

Corrosion behavior of copper and adjacent stainless steel was evaluated in the test loop simulating cooling systems of an electronic instrument and others. Laboratory tests were conducted in low conductivity pure water at 40°C. These test results showed that the corrosion of copper was remarkably suppressed at 0.1μS/cm of water conductivity. This behavior was assumed to be due to stabilization of oxide films formed on copper in this conductivity region. Pitting was caused on adjacent stainless steel (Type 316L) in water containing more than 10ppm copper ions. As metallic copper was deposited around pits, it was assumed that the corrosion of stainless steel was progressed through the reduction process of Cu²⁺ ions. Based on the results, a water control procedure of cooling system was developed.