Quantitative Evaluation Of Buried Pipeline Reliability Based On Magnetic Memory Technology

Metal magnetic memory testing is a new type of non-contact non-destructive testing method.This method can not only discover macroscopic defects,but also find stress concentration areas,thus showing its unique advantages in the field of non-destructive testing.Since the advent of the last century,magnetic memory technology has developed rapidly.Especially in the recent two years,useful attempts have been made in the qualitative detection of non-contact magnetic memory in buried pipelines,reflecting its advantages of convenience and efficiency,but difficulties have been encountered in quantitative detection and reliability evaluation.In view of the difficulties in quantitative evaluation of magnetic memory in buried pipelines,this paper extends the risk assessment theory on the basis of risk assessment theory.Firstly,six commonly used corrosion pipeline defect prediction methods are introduced and their application scopes are compared and analyzed.The magnetic memory test was designed using the variables involved in the Modified B31G standard.The influence of the magnetic memory parameters on the defect variables is characterized by the correlation coefficient of Kendall and Spearman,and a function relation between the characteristic parameters and the pressure,the depth and the length of the defect is established.The error of function relation is verified and the error function model is corrected.The comprehensive formula is a function of the failure pressure and the characteristic variables of magnetic memory.Based on the theoretical basis of reliability and the limit state support,a multi-parameter fusion evaluation of corroded pipelines based on magnetic memory technology is established.The state distribution rule of selected magnetic memory parameters was determined by Origin software and K-S test method.On the basis of Monte Carlo theory,the reliability evaluation model calculates the reliability of different depths,pressures and magnetic memory parameters.It provides scientific basis for maintenance and replacement of buried pipelines at the lowest risk level in actual projects.