ZHENG Fangping, CUI Xionghua, WANG Hongzhe, et al. ANALYSIS OF BOLT FAILURE FOR HIGH PRESSURE BYPASS VALVE OF ULTRA-SUPERCRITICAL 600 MW UNIT[J]. Thermal power generation, 2012, 41(8): 86-90.
ZHENG Fangping, CUI Xionghua, WANG Hongzhe, et al. ANALYSIS OF BOLT FAILURE FOR HIGH PRESSURE BYPASS VALVE OF ULTRA-SUPERCRITICAL 600 MW UNIT[J]. Thermal power generation, 2012, 41(8): 86-90.DOI:
超超临界600MW机组高压旁路阀螺栓失效分析
摘要
某电厂超超临界600MW机组的高压旁路阀部分螺栓发生不同程度地损坏
通过宏观检验、合金成分分析、力学性能检验、金相检验及能谱分析等方法
对螺栓失效原因进行分析。结果表明:螺栓失效原因为应力腐蚀开裂
与螺栓原材料固溶处理状态较差、硬度过高及螺纹加工硬化有关。对此
提出了加强备品螺栓检验
控制安装时的预紧力
避免污染腐蚀等预防措施。
Abstract
Through macroscopic inspection
alloy composition analysis
mechanical property detection
metallographic examination
fracture analysis
and energy spectrum analysis etc.
the causes leading to bolt failure of high-pressure bypass valve for an ultra-supercritical 600 MW unit have been analysed.Results show that the failure was due to stress corrosion cracking
which was mainly resulted from bad solid-solution treatment of bolt raw material
too high hardness
and work hardening of threads.For this
some preventive measures
such as strengthening inspection of spare bolts
controlling the pretightening load during installation