含双腐蚀缺陷高钢级油气管道剩余强度研究
Residual Strength of High Grade Steel Oil and Gas Pipelines with Double Corrosion Defects
申玉健1
作者信息
- 1. 中国石油天然气股份有限公司华北油田分公司 河北 沧州 062550
- 折叠
摘要
为了加强含双腐蚀缺陷高钢级管道的安全评价,基于塑性失效准则,利用Workbench有限元分析软件对缺陷处的等效应力和剩余强度进行了模拟,考察了缺陷长度、缺陷深度和缺陷间距等参数对剩余强度的影响,利用99%相互作用准则确定极限作用距离,形成双腐蚀缺陷剩余强度评价方法,并进行数据验证.结果表明,随着内压的增加,管道先后经历弹性阶段、屈服阶段和强化阶段;在缺陷深度较深时,轴向间距对缺陷轴向分布时的最大等效应力影响较大,不同环向间距下的最大等效应力几乎不发生变化.当相邻腐蚀轴向间距系数n小于2.5、相邻腐蚀环向间距系数c小于1.26 时,需考虑缺陷间的相互作用和影响;修正后公式可用于计算含双点腐蚀缺陷的高等级钢剩余强度,结果较DNV-RP-F101 规范更接近有限元分析结果,最大相对误差不超过 1.74%.研究结果可为提高管道完整性管理水平提供理论依据和实际参考.
Abstract
In order to strengthen the safety evaluation of high grade steel pipelines with double corrosion defects,based on the plastic failure criterion,the equivalent stress and residual strength at the defect were simulated by using Workbench finite element software,and the effects of many parameters,such as the length of the defect,the depth of the defect and the spacing of the defect,on the residual strength were investigated.The 99%interaction criterion was used to determine the ultimate action distance of double corrosion defects,the evalua-tion method of the residual strength of double corrosion defects was formed,and the data were verified.The results show that with the in-crease of internal pressure,the pipeline goes through elastic stage,yield stage and post-yield strengthening stage successively.When the de-fect depth is deep,the effect of axial spacing on the maximum equivalent stress is larger,but the effect of defect depth on the maximum equivalent stress is smaller.When n<2.5 and c<1.26,the interaction and influence between corrosion defects should be considered.The modified formula can be used to calculate the residual strength of high grade steel with double corrosion defects.The calculated result is clos-er to the experimental value than DNV-RP-F101 specification,and the maximum relative error is less than 1.74%.The research results can provide theoretical basis and practical reference for improving the level of pipeline integrity management.
关键词
双腐蚀缺陷/高钢级钢/管道/剩余强度/等效应力/极限距离Key words
double corrosion defects/high grade steel/pipeline/residual strength/equivalent stress/limit distance引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据