Investigation of Factors Affecting Corrosion Inner Steel Pipe for Transmission Tower

Abstract The degradation of aged power transmission systems has become a serious problem. In particular, in steel pipe towers, the internal corrosion of steel pipe beams is an issue, because it is difficult to assess from the external appearance. The prediction of the relationship between the frequently corroded sites inside steel pipes and the corrosion rate can contribute to the management and maintenance of steel pipe towers. Because these towers are exposed to the atmosphere, corrosive substances such as sea salt and moisture can be easily introduced into the steel pipes, resulting in the non-uniform distribution of corrosion conditions in the longitudinal direction. The behavior of such corrosive substances introduced in steel pipes is considered to depend on the meteorological conditions. Furthermore, the corrosion condition of steel pipes is expected to depend on their orientation whether they are horizontal or inclined. In our previous work1, we proposed a method for monitoring the corrosion inside steel pipes involving the installation of several atmospheric corrosion sensors (ACM sensors) arranged in a pipe in the longitudinal direction. In this study, using this method while observing the meteorological conditions, the effects of the wind direction and speed on the corrosion rate inside steel pipes were investigated. ACM sensors revealed that the longitudinal distribution of the corrosion rate inside a steel pipe depends on whether it is horizontal or inclined 45°. It also appears that the wind direction and speed affect the corrosion rate inside steel pipes. This study showed that the corrosion behavior inside steel pipes can be predicted from the direction and speed of wind in the test field.