Electrochemical Corrosion Study of 20MnTiB High Strength Bolt Under the Simulation of Humid Climate in Chongqing

High strength bolts for steel structure bridges have been used in humid environment for a long time, and are prone to corrosion and failure under the combined action of corrosion environment and load. The electrochemical corrosion performance of 20MnTiB high strength bolt was studied by simulating the humid climate in Chongqing. The results were shown that under the same condition, the corrosion resistance was increased both with the increase of pH and the increase of corrosion time. According to the EDS and XRD results, after immersion at different pH values for 168 h, the main corrosion products are Fe2O3, Fe3O4 and FeOOH. All the results demonstrated that after immersion at different pH values for 168 h, the sample corrosion resistance was improved, and was significantly increased with the increase of pH value, which is closely related to the corrosion product film on the sample surface.