Abstract
One of the methods to monitor metal corrosion behavior in the atmosphere as a mass change of the ng/cm2 order continually is the quartz crystal microbalance（QCM）method. The corrosion rates of multiple metals were simultaneously monitored with the multi-channel QCM sensors, and the concentration of corrosive gases were studied by the QCM measurement based on the inverse estimation method. The relationship between the corrosion rates and the environmental factors was formulated by considering the corrosion rates of silver, cobalt, and copper as the function of SO2, NO2, H2S and relative humidity. And the inverse estimation of the concentrations of corrosive gases can be derived from the basis of these approximate equations. Moreover, in order to evaluate the atmospheric corrosivity in an electrical control unit room in a steelmaking plant, the temperature, the relative humidity and corrosion rates of metals on QCM sensors were monitored. The temperature, the relative humidity, and the corrosion rates in a given day were distributed according to the normal probability law. The concentrations of H2S, SO2 and NO2 were estimated from the mean values of the relative humidity and the corrosion rates. The gas concentrations thus obtained by this method were roughly close to those analyzed by conventional measurement methods. The atmospheric corrosivity will be able to estimate based on the monitoring of the corrosion rates with multi-channel QCM sensors.
