含砂海水对40Cr钢加速冲刷腐蚀性能影响

目的研究40Cr钢在实际海水中的冲刷腐蚀性能。方法采用自制旋转冲刷实验装置,模拟实际海洋环境对40Cr钢进行实验。试验介质为含有质量分数为0.15%、0.3%、1%石英砂(300目左右)的青岛海域天然海水,冲刷流速分别为1、3、5 m/s。用交流阻抗谱和极化曲线测试检测其冲刷腐蚀性能,采用失重法测量冲刷腐蚀速率,并用扫描电镜观察其表面形貌,用XRD、EDS技术检测腐蚀产物成分。结果当流速一定,石英砂的质量分数为0.3%时,腐蚀速率最小,交流阻抗谱和极化曲线结合分析显示,此时最耐腐蚀,腐蚀产物成分为FeO(OH)。当含砂量一定时,随着流速的增加,试样腐蚀速率快速增加,耐蚀性逐渐下降,腐蚀产物主要成分为Fe O(OH)。结论流速对40Cr的冲刷腐蚀速率影响较大,而含砂量对冲刷腐蚀速率的影响较小。

Erosion-corrosion Behavior of 40Cr Steel in Sandy Seawater

Objective To research the erosion corrosion performance of 40Cr steel in actual seawater. Methods The experiment was carried out with a self-made rotary scouring experimental apparatus to simulate the actual marine environment to test 40Cr steel. The test medium was natural seawater of Qingdao which containing 0.15%, 0.3%, 1% quartz sand (about 300 mesh), and the flushing flow rates were 1 m/s, 3 m/s and 5 m/s, respectively. The erosion corrosion performance was measured by AC impedance spectrum and polarization curve. The corrosion rate was measured by the weight loss method. The surface morphology was observed by scanning electron microscopy. And the corrosion product composition was analyzed by XRD and EDS. Results When the flow rate was constant, the sand content was 0.3%, and the corrosion weight loss rate was the smallest. The combination of AC impedance spectrum and polarization curve showed that the corrosion resistance was the highest, and the corrosion product was FeO(OH). As the flow rate increased, the corrosion loss rate of the sample increased rapidly, and the corrosion resistance decreased gradually. The mainly corrosion product composition was FeO(OH). Conclusion The flow rate has a great influence on the erosion-corrosion rate of 40Cr, while the sand content has little effect on the erosion-corrosion rate.