目的 为了提高钢材表面的耐腐蚀性能。方法 采用含正硅酸乙酯（TEOS）的硅烷液，在40Cr合金钢表面制备TEOS改进硅烷保护膜，并采用正交试验法优选出了最佳TEOS改进硅烷液的工艺参数。采用扫描电子显微镜（SEM）、中性盐雾实验失重法、电化学阻抗法和极化法对其成膜性能和耐腐蚀性进行测试。结果 TEOS改进硅烷膜的耐硫酸铜腐蚀时间相对于硅烷膜提高了近50%。电化学极化测试可以看到TEOS改进硅烷膜的腐蚀电位正移，腐蚀电流密度大幅度下降至1.883×10?6 A/cm2。电化学阻抗谱测试中，在阻抗-频率Bode图中低频区，杂化硅烷膜试样的阻抗值大于硅烷膜试样的阻抗值，表现出良好的抗腐蚀性能；相角-频率Bode图显示TEOS改进硅烷膜在中高频区出现一个宽大的平台区，而且在中高频区相位角度数大于硅烷膜的相位角度数，表现出良好的容抗性能，表明TEOS改进硅烷膜能大幅度提高40Cr的耐腐蚀性。结论 所制备的TEOS改进硅烷保护膜具有较好的成膜性，该硅烷膜坚实致密，且所形成的膜结构具有较好的耐腐蚀性能。

The work aims to improve corrosion resistance of steel surface. TEOS-modified silane film was prepared on 40Cr steel surface using silane solution containing tetraethoxysilane (TEOS). Optimal process parameters of TEOS-modified silane film were selected in orthogonal testing method. Film forming property and corrosion resistance of the TEOS-modified silane film were tested by means of scanning electron microscope (SEM), neutral salt spray test, and in electrochemical impedance and polarization method. Copper sulfate corrosion resistance time of TEOS-modified silane film increased by nearly 50% compared with that of silane film. Corrosion potential of TEOS-modified silane films shifted positively in the electrochemical polarization test. Cathode current density decreased sharply to 1.883×10?6 A/cm2. In the electrochemical impedance test, impedance-frequency Bode figure showed that impedance value of complex silane film in low and medium frequency range was higher than that of silane film, indicating that the former exhibited excellent corrosion resistance. Phase angle-frequency figure showed that a wide flat zone of TEOS-modified silane film was present in medium-high frequency range, and its phase angle exceeded that of silane film in medium-high frequency range, showing that the film exhibited excellent condensance property and silane film could significantly improve corrosion resistance of 40Cr. The TEOS-modified silane with compact and dense structure exhibits excellent film forming property and can improve corrosion resistance of the 40Cr steel.