Research on corrosion behavior of truck body steel in chlorine-containing sulfuric acid environment

In this work, the corrosion behavior and corrosion mechanism of S500AW weathering steel in sulfuric acid environment were studied by the analysis methods of immersion test, corrosion weight loss analysis, macroscopic morphology analysis, SEM, XPS and electrochemical test. The results show that the corrosion rate of S500AW is significantly lower than that of Q345B. The corrosion products of both steels contain FeO, Fe2O3, Fe3O4 and FeOOH, while the corrosion product layer of S500AW also contains Cu, CuO and Sb2O3. The presence of Cu and Sb2O3 helps to improve the adhesion of corrosion produt layer to the substrate. And the corrosion product layer gradually reaches a dynamic balance during dissolution and regeneration, which prevents the invasion of corrosive ions to a certain extent. In addition, the Sb element will consume local H+ during the formation of Sb2O3, inhibiting the oxygen reduction reaction and reducing the local acidity. These reasons all make the S500AW substrate corrode in a relatively mild environment and make S500AW has a better corrosion resistance.