汽车内腔防腐涂层的加速老化性能评价  

Evaluation of the Accelerated Aging Properties of Anti-Corrosive Coatings for Inner Cavity of Automobile

作　　者：苏建 丛玉凤[1] 黄玮[1] 姜传东 SU Jian;CONG Yu-feng;HUANG Wei;JIANG Chuan-dong(College of Petrochemical,Liaoning Shihua University,Fushun 113001,China;College of Chemistry and Environmental Sciences,Kashgar University,Kashi 844000,China)

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001 [2]喀什大学化学与环境科学学院,新疆喀什844000

出　　处：《材料保护》2022年第4期195-202,共8页Materials Protection

基　　金：辽宁省重点研发计划项目(2019JH2/10100005);汽车空腔防腐蜡研制项目(2019010245)资助。

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10^(9)Ω·cm^(2)量级以上;中期(第4~6个周期),|Z|_(0.01 Hz)为10^(5)~10^(8)Ω·cm^(2)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10^(5)Ω·cm^(2)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。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 0th to 2nd cycle)had good corrosion resistance,and low frequency electrochemical impedance|Z|_(0.01 Hz) was on the order of 10^(9)Ω·cm^(2) or more;in the middle stage(the 4th to 6th cycle),|Z|_(0.01 Hz) was on the order of 10^(5)~10^(8)Ω·cm^(2),the size and quantity of internal micropores increased,and the corrosion resistance was obviously attenuated;in the late stage(8th cycle),local bulges appeared on the surface,|Z|_(0.01 Hz) was on the order of 10^(5)Ω·cm^(2) 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.

关 键 词：汽车内腔 防腐涂层 加速试验 老化动力学 电化学阻抗 

分 类 号：TQ64[化学工程—精细化工]