2016 Volume 65 Issue 8 Pages 341-349
The experiment for developing ant nest corrosion was conducted by using two kinds of copper tubes; a phosphorous deoxidized copper (PDC) tube containing 0.028% P and an oxygen-free copper (OFC) tube without P. Ant nest corrosion occurred on both PDC and OFC tubes after the exposure to an atmosphere derived from 100, 1000 and 10000ppm formic and acetic acid solutions. The propagation rate of ant nest corrosion occurred on the PDC tube was faster than that on the OFC tube, whereas the weight loss of the OFC tube after the exposure test was higher than that of the PDC tube. In the immersion test of PDC and OFC tubes in 100 and 1000ppm formic and acetic acid solution, ant nest corrosion occurred on copper tubes except for the OFC in acetic acid solution. Since the ant nest corrosion is developed on the OFC tube containing none of P, phosphorous in copper is not necessarily required for the formation of ant nest corrosion.
