EVALUATION OF CORROSION RATE OF CARBON STEEL INATMOSPHERIC ENVIRONMENT BY ACM(ATMOSPHERICCORROSION MONITOR) TYPE CORROSION SENSOR

摘要

ACM (Atmospheric Corrosion Monitor) type corrosion sensors, consisted of a Fe-Ag galvanicrncouple, and carbon steel coupons were exposed at five exposure test sites; 1)Tsukuba, as a ruralrnatmosphere, 2)Shimizu, as a mild marine atmosphere, 3)Choshi, as a rural/marine atmosphere, and 4)rnNishihara and 5)Miyakojima, as severe marine atmospheres with large amount of airborne sea salt. Byrnanalyzing the magnitude and time variation of I, the occurrence and duration of rain, dew and dry periods,rnTrain, Tdew and Tdry, respectively, could be distinguished and determined. And by referencing to thernempirical I-RH calibrating curve, the amount of deposited sea salt, Ws, could also be estimated.rnCorrosivities of those exposure sites were evaluated with environmental factors, Ws, Train, Tdew and Tdry.rnACM Sensors And relationship between corrosion rate of carbon steel and those factors were studied.rnMoreover, equations to estimate corrosion rate of carbon steel were suggested with those factors andrnelectricity of sensor output.