采用高速氧燃料火焰喷涂（HVOF）方法在普通碳钢表面制备了镍基合金涂层，对其组织结构进行了观察，并利用电化学方法对其在水溶液中的腐蚀行为进行研究，探讨HVOF涂层应用于水介质环境中的可能性。试验结果表明，NiCrBSi喷涂层在1mol/L NaOH溶液中表面能够形成致密钝化膜，耐碱腐蚀的性能最好。涂层在酸性溶液中的腐蚀速度大于在中性3.5%NaCl溶液中的腐蚀速度，利用冰醋酸将3.5%NaCl溶液的pH值调整到3，可以提高实验结果的重现性。酸性溶液中，只要被测试表面处于活性溶解状态，腐蚀试验重现性都能满足要求。另外，缺陷越少涂层的耐蚀性越好，减少涂层中的孔隙等缺陷是提高涂层耐蚀性的关键。
The nickel-based alloy powder was sprayed to a steel substrate using HVOF, and the corrosion resistance of the coatings was evaluated using electrochemical tests, so as to offer an experimental basis to expand a promising applied field of HVOF in aqueous medium. The results show that NiCrBSi coating has excellent corrosion resistance in alkali solution, because the surface can keep in a self-passivation condition. The corrosion current of the coating in sour solutions is bigger than that in 3.5%NaCl, and the corrosion caused by Cl- is serious than that caused by SO42-. The reproducibility of the test results can be improved when the 3.5%NaCl aqueous solution is acidified with acetic acid, and using a corrosive medium that keep the tested surface in an active-dissolved condition can get the same purpose. The more less the defects in the coating, the better the corrosion resistance. Improving the quality and reducing the porosity of coatings is the key to get the coatings with high corrosion resistance.
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