The Study On Red Soil Corrosion By The Technological Direct, Continuous Monitoring

Direct,continuous,in-situ monitored the resistance changes of X70 pipeline steel in dilute H2SO4 solution and typical soil by a self-designed metal corrosion monitoring and control system in this paper. Calculated X70 pipeline steel corrosion in Jiangxi red soil depth and corrosion rate through the sample resistance changes. Discussed the law of the X70 pipeline steel samples which corrode for 6 months in red soils in Jiangxi Province through the sample resistance changes.Designed to monitor resistance of metal rod and plate fixture which can be continuous, direct and in-situ monitored the resistance changes of rod and plate-like metal after a four-wire micro-European Instrument for modification and the accuracy of resistance measurement up to 0.1 micro-ohms. Obtained corrosion depths and corrosion rates of metal through the resistance changes by the relevant formula.Direct, continuous, in-situ monitored the resistance changes of X70 pipeline steel which corrode for 24 hours in dilute H2SO4 solution by resistance method and the sheet resistance method. Metal corrosion monitoring system can monitor the corrosion depth of metal in dilute H2SO4 solution by experiments. There had a good consistency between calculate the depth by resistance method and calculate the depth by measurement. Obtained the accuracy of the corrosion depths up to 70 nm by resistance method. Within the range of 217.25?m, the maximum and average differences of corrosion depths obtained from measurement and resistance method are 3.25?m and 2.39?m respectively. Within the range of 46.72?m, the average differences of corrosion depths obtained from weight loss method and sheet resistance method are 1.95?m. Calculate the corrosion depths by sheet resistance method can obtain a higher stability data than Calculate the corrosion depths by resistance method.Direct, continuous, in-situ monitored the corrosion depths of X70 pipeline steel,45# steel and 304 stainless steel which all corrode for 6 months in red soil by resistance method and the corrosion depths are 68.67?m,107.48?m and 2.33?m.They were divided into three stages corrosion and three stages of the increased resistance data follow the parabolic law change. Their corrosion resistance in Jiangxi red soil is: 304 stainless steel> X70 pipeline steel>45# steel.