ATMOSPHERIC CORROSION OF PURE COPPER DURING INITIAL EXPOSURE STAGE IN SHENYANG ATMOSPHERE
沈阳大气环境下纯铜的初期腐蚀行为

Atmospheric corrosion of pure copper under sheltered and unsheltered exposure condition during 1 year period in Shenyang atmosphere was studied. Atmospheric corrosion rate of pure copper, composition and protectiveness of corrosion product of pure copper was different under the different exposure conditions. Corrosion rate of pure copper exposed to unsheltered condition was higher than that exposed to shelter. Especially during rainy season, runoff by rain made the copper experience the longer wet time, and thus accelerated corrosion of pure copper evidently. The main corrosion product of copper under the different exposure conditions was Cu2O, there were still Cu4SO4(OH)6.H2O and (Cu4SO4(OH)6) under shelter. However, effects of runoff and dissolution by rain on corrosion products made a low formation process of Cu4SO4(OH)6.H2O, only Cu2O was identified after 6 months exposure under unsheltered exposure condition, Cu4SO4(OH)6.H2O was not found until 12 months exposure period. The thicker and compact corrosion product film had been formed under the unsheltered exposure, which could inhibit the cathodic reaction of copper corrosion effectively, and thus had the better protectiveness.