Corrosion characteristics and anticorrosion life prediction of galvanized iron towers

In order to effectively evaluate the impact of corrosion on the design life and anti-corrosion service life of long-term service poles and towers, scanning electron microscopy, salt spray corrosion tests, and theoretical analysis calculations were used to study the changes in appearance morphology, corrosion rate, microstructure after corrosion, and types of corrosion products of galvanized angle steel in a salt spray corrosion environment for 12 to 60 days. Based on the variation law of atmospheric exposure corrosion of Zn and corrosion theory calculation, the acceleration ratio of salt spray test and atmospheric exposure test for galvanized angle steel in C4 atmospheric environment was calculated, and the service design life and anti-corrosion service life of galvanized poles and towers were reasonably predicted. The research results indicated that the average corrosion rate of galvanized angle steel decreased significantly after 12 to 60 days of salt spray corrosion. The formation of corrosion products Zn₅(OH)₆(CO₃)₂ and Zn₅(OH)₈Cl₂H₂O is the main factor that reduces the corrosion rate of galvanized angle steel. The designed service life of galvanized towers in a C4 atmospheric corrosive environment was 43.0-48.5 days, and the actual service life was 53.2-64.7 years.