Evidence for an unusual temperature dependence of the atmospheric corrosion of zinc

The atmospheric corrosion behavior of zinc in the presence of NaCl has been investigated using well-controlled laboratory exposures in 95% RH air at ten different temperatures in the range -4 to 22\ub0C. Results show that a critical temperature (? -0.5\ub0C) exists in zinc corrosion above which the rate of corrosion is constant/independent of temperature, and, below which there is a positive correlation between temperature and corrosion rate. The corrosion products formed above and below -0.5\ub0C are also entirely different. While simonkolleite, hydrozincite and zinc carbonate hydroxide are the main corrosion products at T ?-0.5\ub0C, the same compounds are absent at