Assessment of potential service-life performance for MarBN steel power plant header under flexible thermomechanical operations
Assessment of potential service-life performance for MarBN steel power plant header under flexible thermomechanical operations
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DOI：
10.1016/j.ijfatigue.2020.105565
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发表时间：
2020-06-01
影响因子：
6
通讯作者：
Sun, W.
中科院分区：
文献类型：
--
作者：
Li, M.;Benaarbia, A.;Sun, W.
对9 Cr钢过热器出口集箱在实际亚临界和未来超超临界工况下的寿命进行了评估。提出的方法是通过高温应变控制疲劳试验，温度和时间相关的热机械疲劳分析的统一粘塑性模型，和Smith-Watson-Topper临界平面多轴寿命预测准则的组合程序实现的。理想化的操作瞬态的样本，特别注意的启动周期是完全耦合的计算建模集管组件的高温性能评估。预测结果表明：（i）封头壳体内孔鞍在焊接区域的关键位置，导致早期潜在的疲劳裂纹萌生，和（ii）在亚临界条件下的预测寿命合理相关的工业经验。由MarBN制造的在超超临界条件下运行的蒸汽集管与在亚临界条件下运行的P91集管具有相当的寿命性能。
This paper is concerned with the service-life assessment of 9Cr steels superheater outlet steam header subjected to realistic subcritical and future ultra-super critical flexible operating conditions. The proposed methodology is achieved via a combined program of high temperature strain-controlled fatigue tests, temperature- and time-dependent unified viscoplastic model for thermomechanical fatigue analysis, and Smith-Watson-Topper critical plane criterion for multi-axial life prediction. Samples of idealised operational transients with particular attention on the starting-up cycle is fully coupled with the computational modelling of header component for the high temperature performance assessment. The predicted results indicate that: (i) the header shell inner-bore saddles at weld regions are the critical locations that lead to earlier potential fatigue crack initiation, and (ii) the predicted lifetime under subcritical conditions correlates reasonably with the industrial experience. A steam header manufactured from MarBN operating under ultra-super critical condition is shown to have comparable life performance with the P91 header operating under subcritical condition.