Room temperature creep behaviors of base metal and welding materials for X80 pipeline steel
Room temperature creep behaviors of base metal and welding materials for X80 pipeline steel
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DOI：
10.1016/j.msea.2022.144038
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
Peng Wang;J. Zhi;W. Hao;Jiamiao Xie;Fenghui Wang;C. Huo
中科院分区：
文献类型：
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作者：
Peng Wang;J. Zhi;W. Hao;Jiamiao Xie;Fenghui Wang;C. Huo
X80管线钢的室温蠕变行为被认为是管线钢失效的一个合理原因，因此受到越来越多的关注。为了研究加载应力、加载速率以及蠕变-疲劳交互作用对室温蠕变的影响，在加载应力从0.85σ s变化到1.05σs的条件下，对母材和焊接试样进行了三种类型的室温蠕变试验（σ是材料的屈服强度），加载速率从0.63 kN/min变化到1.23 kN/min。试验结果表明，X80管线钢的室温蠕变对加载应力和加载速率有很强的依赖性，但当加载应力低于0.85σs时，没有蠕变发生。1h疲劳载荷对蠕变没有影响，第二次蠕变应变远小于第一次蠕变应变。揭示了母材和焊接区的室温蠕变和位错蠕变机制。此外，基于Norton幂函数理论，得到了常温下母材和焊接试样蠕变第一阶段和第二阶段与加载应力的非线性关系式。研究结果可为X80管线钢及相应焊接区的室温蠕变研究提供参考。
The room temperature creep behavior of X80 pipeline has attracted increasing attention because it is considered to be a reasonable cause of failure in pipeline steel. In order to investigate the influence of loading stress, loading rate and creep-fatigue interaction on the room temperature creep, three types of room temperature creep experiments of base metal and welding specimens were carried out when loading stress changes from 0.85σsto 1.05σs(σsis the yield strength of material) and loading rates changes from 0.63 kN/min to 1.23 kN/min. The results of experiments show that the room temperature creep of X80 pipeline steel strongly depends on the loading stress and loading rate, but no creep was measured when loading stress is lower than 0.85σs. One hour fatigue load has no effect on the creep, and the second creep strain is much smaller than the first creep strain. The room temperature creep and dislocation creep mechanisms of the base metal and welding zones are revealed. In addition, the nonlinear creep expression of primary and second stages related to loading stress at room temperature are obtained to evaluate the base metal and welding specimens based on Norton power function theory. The results obtained from the study will provide a reference to the research of room temperature creep of the X80 pipeline steel and corresponding welding zone.