Corrosion Characteristics of Q370 qENH Weathering Bridge Steel

Currently, Q370qENH weathering steel has a wide application in uncoated railway steel bridges due to its satisfactory atmospheric corrosion resistance, low conservation cost, and good mechanical properties. However, the research on the corrosion characteristics of Q370qENH in uncoated weathering steel bridges is limited. This study investigated the outdoor and indoor corrosion behavior of Q370qENH through atmospheric corrosion test and wet-dry salt spray corrosion test. First, the corrosion acceleration model of the two corrosion methods was obtained by the loss-weight method, and the correlation between them was analyzed. Moreover, the Q370qENH corrosion prediction model was determined. Finally, the rust layer characterizations under different corrosion times were analyzed by SEM. The experiment and analysis results show that the wet-dry salt spray corrosion test shortens the testing time of simulating and assessing the corrosion behavior of weathering steels in the atmosphere. The outer rusting layer is loose and primarily composed of γ–FeOOH, and the inner rusting layer is stable and dense, principally containing α–FeOOH. This study can provide a reference for the design of uncoated weathering steel bridges.