Predicting the failure and remaining life of gas pipelines subject to stress corrosion cracking

摘要

For safe and reliable oepration,engineerin procedrues are needed to predict the failure and remaining life of gas pipelines that are subject to stress corrosion c4racking (SCC).Inelastic fracture mechanics (IFM) procedures that employ the J integral have been developed to evaluate the integrity of pipleines with crack-like flaws.These IFM procedrues are extensions of well established mehtods for evalauting the integrity of pipelines with corrosion flaws.they are implemented by means of ocmputerized calculations because of the comlexity of hte numerical analyses requreid for their applciation.Failure predictions are based on either a J fracture toughness criterion or flow strength criterion,depending on which one predicts the lower failure stress or smaller critical flaw size.Remaining SCC life is ocmputed as the time requred for the flaw3 to grow from its initial size to a final size that is predicted to cause failure at the operating pressure.