【摘要】 针对汽车内腔实际服役环境的特点，采用湿热试验、盐雾试验和电化学交流阻抗技术对涂层进行评价并建立老化动力学方程。在加速老化试验下，涂层湿热试验600 h内、盐雾试验达360 h内涂层完好。内腔涂层在3.5%（质量分数）NaCl溶液中25℃下失效老化可以分为老化初期，中期及后期3个阶段；老化初期（第0～2个周期）抗腐蚀性能完好，低频电化学阻抗|Z|_{0.01 Hz}为10⁹Ω·cm²量级以上；中期（第4～6个周期）,|Z|_{0.01 Hz}为10⁵～10⁸Ω·cm²量级，内部微孔增大增多，抗腐蚀性能明显衰减；后期（第8个周期）,表面出现局部鼓包，|Z|_{0.01 Hz}为10⁵Ω·cm²量级及以下，涂层失效。据此建立老化动力学方程，可对内腔防腐涂层的服役寿命和防护性能进行预测和评估。更多还原

【Abstract】 According to the characteristics of the actual service environment of inner cavity of automobile, the damp heat test, salt spray test and electrochemical AC impedance technology were used to evaluate the coating and establish the aging kinetic equation. Results showed that under the accelerated aging test, the coating was intact within 600 h of the damp heat test and 360 h of the salt spray test. The failure aging of the inner cavity coating in 3.5%（mass fraction） NaCl solution at 25 ℃ could be divided into three stages: the initial stage, the middle stage and the late stage of aging; the initial stage of aging（the 0 th to 2 nd cycle） had good corrosion resistance, and low frequency electrochemical impedance|Z| _{0.01 Hz} was on the order of 10⁹ Ω·cm² or more; in the middle stage（the 4 th to 6 th cycle）, |Z|_{0.01 Hz} was on the order of 10⁵～10⁸ Ω·cm², the size and quantity of internal micropores increased, and the corrosion resistance was obviously attenuated; in the late stage（8 th cycle）, local bulges appeared on the surface, |Z|_{0.01 Hz} was on the order of 10⁵ Ω·cm² and below, and the coating failed. Based on this, establishing the aging kinetic equation could predict and evaluate the service life and protective performance of the inner cavity anti-corrosive coatings.更多还原