材料期刊网

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。

ABSTRACT:Objective To predict the residual life of metal pipe with uniform corrosion. Methods The defects of the method in API579 for predicting the residual life of metal pipes subjected to uniform corrosion were analyzed. Field signature method was used to test the corrosion of a metal pipe with 720 mm diameter and 10 mm thickness in a real-time manner. Totally 15 different posi-tions were randomly selected and tested every 3 months. The changes of metal pipe wall thickness were calculated through the change of the voltage between electrodes at these positions. Results Based on the analysis of the experimental data, the metal pipe wall thickness values decreased gradually with time, and the corrosion rate became faster and faster. The corrosion rate was related to many factors, such as transportation medium, oxygen content, materials of the metal pipe and impurities in the transportation medium. The law of corrosion rate of metal pipes could be obtained by comprehensive analysis of the experimental data. By intro-ducing the influencing factor K of corrosion rate, we exploratorily put forward a mathematical model for predicting the residual life ( Rlife ) of the metal pipeline subjected to uniform corrosion. Conclusion In engineering practice, we can use the method of mathe-matical statistics to analyze large amounts of real-time data and the data recorded during operation, so that we can find the corrosion law of metal pipes in certain circumstances. Finally, we can make life prediction of the metal pipe with uniform corrosion through the mathematical model proposed in this paper.