Research engineerpersonal member, Cominco Ltd.ASTM, Sheridan Park, Ont.
Pages: 17 Published: Jan 1968
A long term exposure program has been carried out at Birchbank, B. C., wherein rolled zinc corrosion data and certain atmospheric factor data were developed. Zinc is sensitive to variations in climatic and atmospheric pollution conditions, and as a result panels exposed on different dates for a specific period of time can corrode at different rates. An empirical equation has been developed for Birchbank which relates corrosion of zinc to the time of wetness of exposed panels and the average atmospheric sulfur dioxide content during the time panels are wet. The equation accounts for most of the observed variation in corrosion losses and is valid for exposure periods of up to 256-weeks' duration. This paper also presents information concerning the relative corrosion rates of the skyward and groundward surfaces of zinc panels, the relationship between time of panel wetness and relative humidity, and the relationship between atmospheric sulfur dioxide as measured by a Thomas autometer and by the lead peroxide method.
atmospheric corrosion tests, zinc, time of panel wetness, sulfur dioxide, lead peroxide method, relative humidity
Paper ID: STP34090S