汽轮机组高调阀油动机支架固定螺栓断裂分析研究  

Analysis and Research on Fracture of Fixed Bolt of Support for High Profile Valve Oil Motor of Steam Turbine Unit

作　　者：吕磊 涂安琪 谢利明 宋楠 LU Lei;TU Anqi;XIE Liming;SONG Nan

机构地区：[1]内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司,呼和浩特010020

出　　处：《青海电力》2023年第2期53-56,共4页Qinghai Electric Power

摘　　要：某电厂汽轮机运行过程中1号高压调速汽阀油动机机架固定螺栓发生断裂失效。为查明螺栓断裂原因,利用宏观分析、化学成分分析、力学性能检测、显微组织检测及断口微区形貌分析等试验方法对断裂的螺栓进行了综合性检测分析。本次汽轮机高压调速汽阀油动机机架固定螺栓断裂的主要原因为螺栓刚性杆向螺纹过渡的第一扣螺纹牙底处属于螺栓应力最为集中部位,在驱动高压调速汽阀频繁动作过程中产生的脉动冲击载荷作用下,螺纹牙底部位发生疲劳开裂形成裂纹源,并在脉动冲击载荷作用下以疲劳形式扩展,最终导致螺栓整体断裂失效。During the operation of steam turbine in a power plant,the fixed bolt of oil motor frame of No.1 high pressure speed regulating steam valve broke and failed.In order to find out the cause of bolt fracture,a comprehensive analysis of the broken bolts was carried out by means of macroscopic analysis,chemical composition analysis,mechanical property detection,microstructure detection and fracture microtopography analysis.The main reason for the breakage of the fixed bolt of the oil motor frame of the steam turbine high pressure speed regulating valve is that the first thread bottom of the bolt rigid rod transitioning to the thread belongs to the most concentrated part of the bolt stress.Under the action of the pulsating impact load generated during the frequent operation of the high pressure speed regulating valve,fatigue cracking occurs at the bottom of the thread and forms a crack source.It expands in the form of fatigue under the action of pulsating impact load,and finally causes the whole bolt to break and fail.

关 键 词：螺栓 裂纹 疲劳开裂 失效分析 

分 类 号：TG115[金属学及工艺—物理冶金]