Pipelines are the most profitable mode of transportation for hydrocarbons. Typically, oil and gas pipelines are made of low carbon steel, whose mechanical properties change due to aging. The changes in mechanical properties can be estimated using an artificial aging process. The mechanical properties studied in this paper (yield strength, ultimate tensile strength, and hardness), have random behavior that can be represented by a generalized extreme value distribution, showing considerable changes in variance and skewness at different aging times. Taking advantage of this feature and considering these changes in the mechanical properties can significantly affect the accuracy of calculated pipeline probability of failure estimation.

管道运输是最有利可图的碳氢化合物运输方式。通常，石油和天然气管道由低碳钢制成，其机械性能会因老化而变化。可以使用人工时效过程来估计机械性能的变化。本文研究的机械性能（屈服强度，极限抗拉强度和硬度）具有随机行为，可以通过广义的极值分布来表示，表现出在不同时效时间下方差和偏度的显着变化。利用此功能并考虑机械性能的这些变化会显着影响所计算管道故障估计概率的准确性。