模拟循环冷却系统黄铜管的腐蚀电化学

Corrosion electrochemistry of brass tube in simulated circlating cooling system

用研制的黄铜管腐蚀监测传感器对模拟循环冷却系统的黄铜管进行了电化学阻抗谱和电化学噪声测试 .电化学阻抗谱测试结果表明 ,缓蚀剂能够在金属表面上形成保护性膜层抑制腐蚀过程 .流速提高时溶液中氧的扩散速度提高 ,使缓蚀剂在HAl77 2管表面上的成膜作用加强 ,腐蚀速度降低 .电化学噪声测试结果表明 ,提高流速对HSn70 1管局部腐蚀敏感性影响不大 ,而HAl77 2管在较高流速下局部腐蚀敏感性提高 ,表明电化学噪声能用于循环冷却系统黄铜管的腐蚀监测 .流速对逆水流方向传感器的影响大于顺水流方向 ,因此实际应用时传感器应顺水流方向放置 ,以减小流速的影响 .研究结果表明 ,所研制的传感器适用于动态条件下黄铜管的电化学测试 .

Brass tube in simulated circlating cooling system was studied by means of electrochemical impedance spectrum(EIS) and electrochemical noise(EN).EIS shows that the inhibitor can react with metal surface or corrosive product and inhibit the corrosion process by forming protective film.With the flow rate increasing, the diffuse speed of oxygen increases and the process of film forming accelerates in HAl77-2 tube,resulting in a decreasing corrosion speed.EN shows that the flow rate has little effect on the susceptibility of pitting corrosion of HSn70-1 tube.But the susceptibility of pitting corrosion of HAl77-2 tube increases with an increasing flow rate.The result is in full agreement with actual conditions.It shows that the electrochemical noise technique is good for corrosion monitoring.The flow rate has a significant effect on the sensor placed countercurrently and has little effect on the sensor placed concurrently.So the sensor should be placed concurrently in application to decrease the effect of flow rate.The result of experiment shows that the sensor can successfully monitor the corrosion in flowing seawater.