【摘要】 采用预拉伸及固溶处理的方法制备粗晶试样，再对试样进行等温时效，模拟研究奥氏体晶粒异常长大的服役Super304H、TP347HFG钢管的显微组织及硬度变化，对其开展剩余服役寿命预测。结果表明：经预拉伸变形和固溶处理后，粗晶试样的平均奥氏体晶粒度为2级；在等温时效过程中，奥氏体晶粒尺寸基本不变，但M₂₃C₆相颗粒持续析出并变得粗大，导致奥氏体晶界宽化。粗晶试样的硬度呈现先增大后减小，再趋于稳定，最后快速单调减小的趋势。基于硬度-P函数法建立了粗晶Super304H、TP347HFG钢管剩余服役寿命预测的数学模型。更多还原

【Abstract】 Coarse grained samples were prepared by pre-stretching and solid solution treatment, and then isothermal aging was carried out on the samples. The microstructure and hardness changes of Super304H and TP347HFG steel pipes with abnormal austenite grain growth were simulated and studied, and the remaining service life was predicted. The results show that the average austenite grain size of the coarse-grained sample was grade 2 after pre-tensile deformation and solid solution treatment. During the isothermal aging process, the austenite grain size was basically unchanged, but the M₂₃C₆ phase particles continued to precipitate and became coarse, resulting in austenite grain boundary widening. The hardness of coarse-grained samples increased first and then decreased, then tended to be stable, and finally decreased rapidly and monotonously. Based on the hardness-P function method, a mathematical model for predicting the remaining service life of coarse-grained Super304H and TP347HFG steel tubes was established.更多还原