Abstract
It has been believed that ant's nest corrosion of copper tubes occurs only in moist vapor phase containing organic carboxylic acid such as formic and/or acetic acid. In this study, copper tubes were immersed in formic acid solution for 28 days to reproduce ant's nest corrosion of copper tubes in liquid phase. Ant's nest corrosion occurred in copper tubes immersed in 1, 5, 10, 100 and 1000 ppm formic acid solutions for 28 days, while the uniform attack occurred in copper tubes immersed in 10000 ppm formic acid solution. It was found that the initiation and propagation of ant's nest corrosion accelerate in the solution containing both formic acid and sulfate ion.
