Effect of Corrosion Defects on the Strength of Pipeline Used for Conveying High Sour Gas

A pipeline containing defects was modeled in solid 186 units. The influence mechanism of the corrosion defects on the strength of pipeline used for conveying high sour gas was analyzed based on the implicit integration algorithm of nonlinear finite element analysis and plastic failure criterion. The correctness of the simulation analyses was verified through the indoor test. The results show that the mechanical behaviors of pipeline containing defects were divided into elastic phase,elastic-plastic phase and plastic reinforcement phase. Slotted and ellipsoid defects greatly reduced the yield point while the influence of spherical defects on the yield point was relatively low. The influence of defects on strength of pipeline was mainly presented as local stress concentration and the stress gradient of ellipsoid defect pipe in the radial direction was the biggest, showing the most obvious stress concentration.