Residual Life Prediction For Corroded Pipeline

Firstly, research aehievement and state of corrosion rsidual life prediction forh the pipeline at home and abroad were introduced.the characteristics of corrosion residual life prediction for long-distance transpsort pipeline were summarized.The existing mehtods of corrosion residual life prediction were analyzed and compared,then were classified.Seeondly,corrosion defects were classified as three types: general corrosion,local coeeosion and pitting coeeosion.And the geometric shapes of all coeeosion defects were modeled.Then,the statistical analysis for the residual life of the whole pipeline and pipe section was done from the direction of probability statistics,the statistic rule of which was found.Following the above, rates of electrochemical corrosion of soil to pipieline were discussed on the basis of electro chemical theory.The different electrochemical models of corrosion tates were done aiming at different corrosion types.Through residual strength evaluation was made fo pipeline,defect dimension,namely defect depth,axial size and loop size,was checked in three directions. Limit corrosion dimensions were detemined. The residual lives of corrosion defects of different tyoes were got basing on the electrochemical models of the corrosion rates and tesidual strength evaluation. This paper put the empahasis of the predictiong method basing on corrosion rate.Finally, hence after analyses of electrochemistry corrosion mechanistic this paper given the certainty coeeosion rate model,offered the detailed prediction processes combined the criteris of residual strength.