地下输油管线腐蚀势态的灰色评估

Grey Evaluation of Corrosive Status of Underground Oil Pipelines

根据表征输油管线运行状态的四项参数即管地电位、阴极保护电位、土壤腐蚀性以及防腐层电阻建立了统计分布模型 ,并对新老管线数据分布模型的均值和方差进行了显著性水平检验 .应用灰色决策 (灰靶 )理论对管线的腐蚀与防护综合势态和运行风险进行了分级和评估 。

The statistical maths analysis and sample distribution assumption tests of four factors, i.e., pipe earth potential (PEP), cathodically protected potential (CPP), corrosion current density (CCD) of 16Mn mild steel in soil and coating resistance (CR) have been accomplished. The CCD and CPP have the same normal distribution in both new and old pipelines. In contrast, the PEP and CR are submitted to log normal distribution. A gray target identification model is used to evaluate and to classify the comprehensive corrosion and protection status of the oil pipelines. The result indicates that the classification is useful for the preventive repair on pipelines.