3PE防腐蚀层失效分析与寿命预测

为了研究3PE防腐蚀层服役过程中的失效问题,采用现场测试、实验室分析和模拟试验等方法对服役中3PE防腐蚀层的剥离问题进行了分析,并对其寿命进行了预测。结果表明:生产过程中表面处理、环氧粉末喷涂等工艺控制不当,服役过程中防腐蚀层破损、阴极保护电位过负等环境因素,均会导致3PE防腐蚀层的剥离;同样的电流密度下,随着时间的延长,阴极剥离距离逐渐增加,且在试验前期增加较快,在试验后期增加变缓;相同时间下,施加的电流密度越高,阴极剥离距离越大,3PE防腐蚀层的特征寿命与电流密度的倒数呈指数关系。

Failure Analysis and Life Prediction for 3PE Anticorrosion Layer

To study the failure problems of 3PE anticorrosion layer,testing on the spot,lab analysis and simulated experiments were used to study the disbondment of 3PE anticorrosion layer and predict its life.The results show that the bad processing control in the production such as surface treatment and fusion bonded epoxy (FBE) spray and the environmental factors such as coating damage and too negative cathodic protection potential caused the disbondment of 3PE anticorrosion layer.At the same current density,cathodic disbondment distance increased as the test period increased.The increase rate of cathodic disbondment distance was high at the early stage of test and was low at the late stage of test.In the same testing period,cathodic disbondment distance increased with the increase of current density and the characteristic life of the 3PE anticorrosion layer had exponent relationship with the reciprocal of current density.