【摘要】 为探究超(超)临界机组P92钢主蒸汽管道长期服役时的组织老化和寿命衰减规律，对1060℃完全奥氏体化后以不同速率冷却后在760℃回火的P92钢试样进行650℃时效，开展显微组织及硬度的测试分析，建立服役态P92钢主蒸汽管道剩余寿命预测模型。研究表明，相同P函数值下，650℃×3358 h时效态与服役态P92试样中的马氏体板条宽化、第二相颗粒粗化及铁素体再结晶等组织老化特征相近。长期时效过程中，完全奥氏体化后冷速(v)越小，P92钢试样马氏体组织稳定性越低，硬度越小，从而建立了基于硬度-v-P函数三元线性关系的服役态P9钢主蒸汽管道剩余寿命预测模型。经验证，该模型比较准确可靠。更多还原

【Abstract】 In order to explore the regularity of microstructure aging and life reduction of the P92 steel main steam pipe of ultra-supercritical unit in long-term service,microstructure and hardness of the P92 steel specimens were tested after complete austenitizing at 1060 ℃ and cooling with different rates,then tempering at 760 ℃,and finally aging at 650 ℃ ． Further,a residual life prediction model of the in-service P92 steel main steam pipe was established. The results show that the aged( 650 ℃ × 3358 h) and in-service specimens of the same P values have the similar microstructure aging characteristics, such as martensite lath widening, secondary-phase coarsening, and ferrite recrystallization. In the long-term aging process,the smaller the cooling rate( v) after complete austenitizing,the lower the martensite stability,and thus the lower the hardness of the P92 steel specimen is. Therefore,a residual life prediction model of the in-service P92 steel main steam pipe is built based on the hardness-v-P ternary linear relationship. After verification,the model is relatively accurate and reliable.更多还原