2014 Volume 63 Issue 5 Pages 333-336
Immersion tests of copper tubes in 100 mg/L formic acid solutions with different concentrations of dissolved oxygen for up to 84 days under room temperature were carried out to investigate the effect of dissolved oxygen on ant's nest corrosion of copper. The ant’s nest corrosion occurred on the copper tubes immersed in formic acid solution with 8.4 and 14.3ppm dissolved oxygen while the corrosion was not observed on the copper tubes immersed in formic acid solution with 2.1 ppm dissolved oxygen. The weight losses of specimens immersed in the formic acid solution with 2.1ppm dissolved oxygen were especially low compared to the weight losses of specimens immersed in the formic acid solution with 8.4 and 14.3 ppm dissolved oxygen. The reduction of dissolved oxygen in the middle of the immersion test inhibited the increase of the weight loss of specimens. Therefore, the dissolved oxygen contributes to an initiation and a propagation of ant’s nest corrosion of copper.
