CORROSION BEHAVIOR OF BRIDGE WEATHERING STEELS IN ENVIRONMENT CONTAINING Cl-
GAO Xinliang, ZHU Miaoyong, FU Guiqin, WANG Feng, DENG Zhiyin
School of Materials and Metallurgy, Northeastern University, Shenyang 110819
Cite this article:
GAO Xinliang ZHU Miaoyong FU Guiqin WANG Feng DENG Zhiyin. CORROSION BEHAVIOR OF BRIDGE WEATHERING STEELS IN ENVIRONMENT CONTAINING Cl-. Acta Metall Sin, 2011, 47(5): 520-527.
Abstract In order to understand the corrosion behavior of bridge weathering steels at marine atmosphere, three type steels containing 3.5% Ni were prepared for alternate wet-dry accelerated corrosion test. Microstructures, rust layer morphologies and characteristics of bridge weathering steels with different Mn and Cu contents at different stages were studied by using optical microscope, XRD and SEM. The results show microstructures of the bridge weathering steels are composed of quasi-polygonal ferrite, acicular ferrite and granular bainite. Corrosion resistance of the steels is improved with Mn content increasing. Distributions of Ni and Mn are uniform inside rust layers, but Cu is enriched at gaps and pores in rust layers. Crystal phases are mainly composed of Fe3O4, γ-FeOOH and α-FeOOH in rust layers, however, the compositions are somewhat different at different stages. The formation of γ-FeOOH and α-FeOOH is closely related to the change in corrosion rate. With increasing Mn content, the formation of γ-FeOOH and α-FeOOH are accelerated and their sizes are restrained.
Supported by Program for New Century Excellent Talents in University (No.NCET-04-0285) and Basic Scientific Research Foundation of National University in China (No.N100102001)
