深度调峰机组TP347H高温过热器管的超温老化  

Over-temperature aging of TP347H high-temperature superheater tube in a deep-peak-regulating power unit

作　　者：张健 王波 杨平 王若民 胡玉璋 汤文明[2] ZHANG Jian;WANG Bo;YANG Ping;WANG Ruo-min;HU Yu-zhang;TANG Wen-ming(Anhui Xinli Electric Technology Consulting Co Ltd,Hefei 230601,China;School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;Department of Technology,Wenergy Hefei Power Generation Co Ltd,Hefei 230041,China)

机构地区：[1]安徽新力电业科技咨询有限责任公司,安徽合肥230601 [2]合肥工业大学材料科学与工程学院,安徽合肥230009 [3]皖能合肥发电有限公司技术部,安徽合肥230041

出　　处：《材料热处理学报》2023年第1期137-145,共9页Transactions of Materials and Heat Treatment

基　　金：安徽新力电业科技咨询有限责任公司科技项目(2020咨-KJ-02)。

摘　　要：在某630 MW超临界机组深度调峰运行中,TP347H高温过热器管发生局部超温,对机组运行产生严重影响。采用显微组织观察和室温拉伸性能测试,结合温度及应力分布的有限元数值模拟,开展了正常运行与超温运行下TP347H高温过热器管的老化评估。结果表明:深度调峰情况下的传热恶化可能造成过热器管超温,管壁最大热应力甚至可能超过TP347H钢管的屈服强度。TP347H高温过热器管频繁超温和高的热应力作用导致服役态TP347H钢管中析出更多的MX和M_(23)C_(6)第二相,尤其是M_(23)C_(6)相颗粒在奥氏体晶界的聚集长大,加剧组织老化。在拉伸过程中,裂纹首先在超温运行管样的奥氏体晶界萌生与扩展,再发生穿晶断裂,奥氏体晶界、晶内存在严重的不均匀变形,从而导致其室温拉伸性能,特别是塑性,显著降低。During the deep-peak-regulating operation of a 630 MW supercritical unit,the local overheating of TP347H high temperature superheater tube has seriously affected the unit operation.The aging evaluation of TP347H high temperature superheater tubes under normal operation and over-temperature operation was carried out by means of microstructure observation and room temperature tensile property tests,combined with finite element numerical simulation of temperature and stress distribution.The results show that the heat transfer deterioration under the condition of deep-peak-regulating may cause superheater tube overheating,and the maximum thermal stress of tube wall may even exceed the yield strength of the TP347H steel tube.Frequent over-temperature and high thermal stress of the TP347H high temperature superheater tube lead to more MX and M_(23)C_(6) second phases precipitated from the TP347H steel tube during service,especially M_(23)C_(6) phase particles that aggregate and grow at austenite grain boundary,which aggravates the microstructure aging of the TP347H steel tube.During the tensile process,the cracks first initiate and propagate at the austenite grain boundary of the over-temperature operation tube sample,then transgranular fracture occurs,and there is serious uneven deformation at the austenite grain boundary and within the grain,which leads to a significant reduction in the room temperature tensile properties of the TP347H high-temperature superheater tube,especially the plasticity.

关 键 词：TP347H耐热钢管 深度调峰 超临界机组 超温老化 有限元数值模拟 

分 类 号：TG142.7[一般工业技术—材料科学与工程]