Abstract The burn-through of in-service welding is affected by pipeline structure, welding procedure and the pressure of the internal medium, etc. It is a high-temperature failure process under the coupling action of structure field, temperature field, and stress field. Predicting the critical burn-through pressure of in-service welding is a challenging problem. In this paper, the existing burn-through criteria were comprehensively summarized and analyzed. Considering the multi-field coupling effect of in-service welding, two kinds of burn-through criteria based on the thermo-mechanical analysis model were proposed innovatively. One is the residual strength three-dimensional integral method. The residual strength in the high-temperature zone of in-service welding was calculated by this method, and the critical burn-through pressure was obtained by further calculation. The selection of effective integral temperature interval is the key to ensure the accuracy of three-dimensional integral calculation of residual strength. It is found that there is a linear relationship between welding heat input and the lower limit of the integral temperature interval. However, for different materials, the linear relation formula is different. The second criterion is the high-temperature plastic failure criterion. The most dangerous path is the one with the largest plastic failure depth along wall thickness. When the von Mises stress over 2/3 of the pipe wall along the most dangerous path is greater than the yield strength at the corresponding temperature, there is a high risk of burn-through. The accuracy of the two criteria in calculating the critical burn-through pressure was verified by in-service welding tests. The results show that the residual strength three-dimensional integration method and the high-temperature plastic failure criterion both have high accuracy and reliability in predicting the burn-through of in-service welding and will have important referential value in predicting the failure of defective pipe under complex temperature and stress conditions.

中文翻译：

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基于残余强度和高温塑性破坏准则的在役焊接烧穿预测

摘要 在役焊接烧穿受管道结构、焊接工艺和内部介质压力等因素的影响，是在结构场、温度场和应力场耦合作用下的高温破坏过程。 . 预测在役焊接的临界烧穿压力是一个具有挑战性的问题。本文对现有的烧穿标准进行了综合总结和分析。考虑到在役焊接的多场耦合效应，创新性地提出了两种基于热力学分析模型的烧穿判据。一种是残余强度三维积分法。用该方法计算了在役焊接高温区的残余强度，并进一步计算得到临界烧穿压力。有效积分温度区间的选择是保证残余强度三维积分计算精度的关键。发现焊接热输入与积分温度区间下限之间存在线性关系。但是，对于不同的材料，线性关系公式是不同的。第二个准则是高温塑性破坏准则。最危险的路径是沿壁厚具有最大塑性破坏深度的路径。当沿最危险路径超过管壁 2/3 的 von Mises 应力大于相应温度下的屈服强度时，烧穿的风险很高。通过在役焊接试验验证了计算临界烧穿压力的两个标准的准确性。结果表明，残余强度三维积分法和高温塑性失效准则在预测在役焊接烧穿方面具有较高的准确性和可靠性，对预测缺陷管的失效具有重要的参考价值。在复杂的温度和应力条件下。