基于FSM无损检测的金属管道均匀腐蚀剩余寿命预测

目的预测均匀腐蚀下金属管道的剩余寿命。方法研究API579中对金属管道剩余寿命预测的方法,具体分析方法中存在的缺陷。采用场指纹法(FSM)对直径为750 mm、壁厚为10 mm的金属管道的腐蚀情况进行实时检测。检测时随机选择15个不同的位置,每隔3个月检测一次,通过检测各个位置电极对之间电压值的变化量计算出管壁厚度的变化值。结果根据对实验数据的分析,随着时间推移,金属管道壁厚值逐渐减小,且减小的速率越来越快。腐蚀速率与运输介质、含氧量、金属管道材料、运输介质中的杂质有着密切关系,全面分析实验数据可以得到金属管道腐蚀速率的规律。加入腐蚀速率影响因素的影响因子K,运用数理统计的方法探索性地提出了一种均匀腐蚀下金属管道剩余寿命Rlife预测的数学模型。结论在工程实际中,可以运用数理统计的方法对大量实时数据及运行过程中已经记录的数据进行分析,从而找到金属管道在特定环境下的腐蚀规律,再通过该数学模型可对均匀腐蚀的金属管道进行寿命预测。

Life Prediction for Metal Pipe of Uniform Corrosion Based on Field Signature Method

In order to Predicting residual life of metal pipe of uniform corrosion. Field signature method is a new measurement method through potential matrix. It can detect metal loss, cracks and potholes caused by corrosion through subtle changes of current on the metal structure. Its detection accuracy is relatively high, and sensitivity is 1% of wall thickness of metal pipe. It can also calculate the corrosion rate of the pipeline. We tested wall thickness of a metal pipe with 720 mm diameter and 10mm thickness. We selected 15 different position. And we test it every 3 months. We calculated the metal pipe wall thickness through the change of the voltage between electrodes. Corrosion rate is related to many factors, such as time, oxygen content, materials of pipe, etc. This paper analyzes the defects of the method that API579 predict the residual life of metal pipes Subjected to uniform corrosion. We have detected metal pipe corrosion through field signature method. Finally, we exploratory put forward the mathematical model for predicting the remaining life of the pipeline Subjected to uniform corrosion. And we add the Impact factor K in the mathematical model.