阴极保护电位与交流干扰对涂层阴极剥离性能的影响

Effect of Cathodic Protection Potential and AC Interference on Cathodic Stripping Properties of Coatings

通过阴极剥离试验,探究不同阴保电位(外加电位)、交流干扰下,新建FBE(熔结环氧)涂层、在役3PE(三层聚乙烯)涂层试样的阴极剥离距离,同时探究了交流干扰和阴极保护共存条件下涂层的阴极剥离距离。通过电化学阻抗谱(EIS)测试,对FBE涂层的阴极剥离过程进行监测。结果表明:当新建FBE涂层试样的交流干扰为60~300 A/m^(2)时,其对涂层阴极剥离的影响较小;新建FBE涂层的阴极剥离距离随外加电位负向偏移、时间延长而增加。对于在役15 a的3PE涂层,外加电位为-1.2 V(CSE)时,在试验初期就迅速发生阴极剥离,后期剥离距离增速明显减缓,且出现典型的保护区、屏蔽区、新剥离区,新剥离区与底层涂层的抗阴极剥离性能有关,正常阴极保护电位范围内,阴保电位负向偏移时,阴极剥离距离增大。当阴保电位为-0.85~-1.0 V时,随着交流干扰强度增加,阴极剥离距离增加,当外加电位为-1.2 V时,交流干扰对阴极剥离的影响较小。

Through cathodic stripping test,the cathodic stripping distance of the newly-built FBE coating and the in-service 3 PE coating samples under different cathodic protection potentials(applied potentials)and AC interference conditions was explored,and the coating performance under the coexistence of AC interference and cathodic protection was also explored.Through electrochemical impedance spectroscopy(EIS)test,the cathodic stripping process of the FBE coating was monitored.The results showed that when the AC interference of the newly-built FBE coating sample was 60-300 A/m^(2),its influence on the cathodic delamination of the coating was small.The cathodic stripping distance of the newly-built FBE coating increased with the negative shift of the applied potential and the extension of time.For the 3 PE coating in service for 15 years,when the applied potential was-1.2 V(CSE),cathodic disbondment occurred rapidly in the early stage of the test,and the growth rate of the peeling distance in the later period slowed down significantly,and there were typical protection zones shielding zones,and new peeling zones.The stripping area was related to the cathodic disbondment resistance of the underlying coating.In the normal cathodic protection potential range,when the protection potential shifted negatively,the cathodic stripping distance increased.When the cathodic protection potential was-0.85--1.0 V,as the AC interference intensity increased,the cathodic stripping distance increased.When the applied potential was-1.2 V,the impact of AC interference on cathodic stripping was small.