某660MW超临界机组过桥汽封螺栓断裂原因分析Analysis on Breakage of Mid-span Sealing Bolt of a 660 MW Supercritical Unit
周伟龙,彭以超,何志瞧,王超,潘雷鸣
ZHOU Weilong,PENG Yichao,HE Zhiqiao,WANG Chao,PAN Leiming
摘要(Abstract)：
介绍某超临界改造汽轮机组在检修时发现过桥汽封螺栓断裂的情况,对断裂螺栓进行了宏观检查、超声检测、光谱分析、金相分析以及力学性能分析,并查阅了Nimonic 80A螺栓的材料特性,分析螺栓断裂可能与该材料在500℃以下产生负蠕变及螺栓吸收冲击功低、高温拉伸强度偏高、高温塑性较差等因素有关。
This paper introduces the breakage of mid-span sealing bolt found in the overhaul of a supercritical steam turbine unit. Macroscopic examination ultrasonic testing, spectrum analysis, metallographic analysis and mechanical property analysis on the broken bolts were conducted. Besides, the material characteristics of Nimonic 80 A bolts were also reviewed. The reason for the bolt fracture of the bolt may be related to the negative creep of the material under 500 ℃, low absorbing impact energy, high tensile strength at high temperature, poor plasticity at high temperature.
关键词(KeyWords)：
汽轮机;Nimonic80A螺栓;过桥汽封;断裂
steam turbine;Nimonic80A bolt;mid-span sealing;fracture
基金项目(Foundation):
作者(Author):
周伟龙,彭以超,何志瞧,王超,潘雷鸣
ZHOU Weilong,PENG Yichao,HE Zhiqiao,WANG Chao,PAN Leiming
DOI: 10.19585/j.zjdl.201909008
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