除冰盐环境下桥梁钢的耐腐蚀性能研究

Corrosion Resistance of Various Bridge Steels in Deicing Salt Environments

采用干湿交替腐蚀实验和全浸腐蚀实验结合锈层物相分析,研究了桥梁钢Q345qENH、Q420qENH和对比钢种Q345qE在除冰盐环境下的腐蚀行为。结果表明:耐候桥梁钢Q345qENH、Q420qENH在除冰盐腐蚀环境的耐蚀能力明显优于Q345qE钢;同种桥梁钢在不同的结构部位受除冰盐腐蚀程度相差较大,Q345qENH、Q420qENH和Q345qE钢干湿交替腐蚀的加速倍率分别是其全浸腐蚀的26.88倍、27.5倍和33.75倍;干湿交替腐蚀实验随着时间的延长锈层物相结构及含量均有所变化,绝缘的非活性物质α-FeOOH相的增加是导致实验后期腐蚀速率下降的重要原因。

The corrosion behavior of bridge steels Q345 qENH and Q420 qENH in deicing salt was studied by means of wet-dry cyclic corrosion test,immersion corrosion test and rust scale characterization,while taking Q345 qE steel as comparison.The results indicate that the corrosion resistance of the Q345 qENH and Q420 qENH weathering bridge steels was better than that of the Q345 qE steel.The drywet cyclic corrosion test results reveal that the Q345 qENH,Q420 qENH and Q345 qE steels show corrosion rates of 26.88,27.5,and 33.75 times higher than those measured in immersion corrosion test,respectively.During dry-wet cyclic corrosion test,the structure and composition of the formed rust scales changed and the amount ofα-FeOOH phase increased gradually with time,which may be an important reason leading to the decrease of corrosion rate at the end of dry-wet cyclic test.