Abstract
Atmospheric corrosion test data for copper plates obtained in various sites in Japan were analyzed. Environmental indices were decided by means of measurement of temperature, humidity, corrosive gas, and sea salt particle in air. The longer the exposed period of time and the higher the environmental indices, the larger the weight loss became. And the correlation among the loss of weight, the exposed period of time and environmental indices was investigated. A simple empirical formula was obtained that showed the loss of weight was approximated by a parabolic function of exposed days, where the coefficients for the square root of exposed days were the functions of environmental indices. The environmental indices are obtainable through the assessment of atmospheric environment and the interactive effect of multiple environmental factors on copper can be taken account, the weight loss of copper plates could easily be estimated.