目的 研究Q235钢在不同流速和不同含砂量环境下的冲刷腐蚀行为。方法 采用旋转冲刷腐蚀试验装置，利用电化学测试手段、表面显微分析以及失重测量等方法分析流速以及含砂量对冲刷腐蚀行为的影响。结果 试样表面主要以腐蚀坑和划痕为主，随流速的增加，试样表面腐蚀坑数目增多，砂粒摩擦造成试样表面有明显划痕。含砂量较小时，试样表面腐蚀坑较大，且比较分散；随着含砂量增加，试样表面腐蚀坑增多，但是腐蚀坑直径减小。随流速的增加，试样表面腐蚀产物膜变得更加致密。随含砂量的增加，试样表面的腐蚀产物膜变厚，出现更加稳定的Fe2O3。海水流速和含砂量均较小时，Q235冲刷腐蚀电化学表征为单层结构腐蚀产物层。随流速和含砂量的增加，电化学表征转变为双层结构的腐蚀产物层，砂粒无法直接作用于基体表面。冲刷流速从1 m/s增加到5 m/s时，冲刷腐蚀速率由0.0113 mm/a增加到0.0309 mm/a，Q235钢最大腐蚀坑深度由34.47 μm增大到281.94 μm。含砂量从0.15%增加到1%时，冲刷腐蚀速率从0.0113 mm/a变为0.0107 mm/a，最大腐蚀坑深度由34.47 μm变化为16.41 μm。结论 Q235钢的腐蚀速率及腐蚀坑深对冲刷流速较为敏感，而对含砂量变化敏感性较小。

The work aims to study the erosion and corrosion of Q235 steel in environment with different flow rates and sand contents. The rotary erosion-corrosion tester was used to study the effects of flow rate and sand content on erosion-corrosion behavior through electrochemical test methods, surface microscopic analysis and weight loss measurement. The surface of the sample mainly includes corrosion pits and scratch. The number of pits increased with the increasing flow rate. The wear of the sand caused obvious scratches on the surface of the sample. When the sand content was small, the pits on the surface of the sample were large and relatively scattered. As the sand content increased, the number of the pits on the surface of the sample increased, but the diameter of the pits decreased. As the flow rate increased, the corrosion product film on the surface of the sample became denser. As the sand content increased, the corrosion product film on the surface of the sample became thicker, and more stable Fe2O3 appeared. When the seawater flow rate and the sand content were small, the erosion and corrosion of Q235 was electrochemically characterized as single-layer structure corrosion product film. With the increase of flow rate and sand content, the electrochemical characterization was transformed into a corrosion product film of double-layer structure, and the sand particles could not directly act on the surface of the substrate. When the flow rate increased from 1 m/s to 5 m/s, the erosion-corrosion rate increased from 0.0113 mm/a to 0.0309 mm/a, and the maximum pit depth of Q235 steel increased from 34.47 μm to 281.94 μm. When the sand content increased from 0.15wt% to 1wt%, the erosion-corrosion rate changed from 0.0113 mm/a to 0.0107 mm/a, and the maximum pit depth changed from 34.47 μm to 16.41 μm. The erosion-corrosion rate and corrosion pit depth of Q235 steel are sensitive to the eroding flow rate, but less sensitive to the change of sand content.