送风机用新型锻铝叶片断裂失效分析  

Failure Investigation on Failed Novel-Aluminum Alloy Blades in Forced Draft Fan

作　　者：范志东[1] 张志博[1] 马翼超 牛坤[1] 郭卫铨 

机构地区：[1]西安热工研究院有限公司,西安710054

出　　处：《西安工业大学学报》2017年第10期760-766,共7页Journal of Xi’an Technological University

基　　金：国家自然科学基金项目(51601145)

摘　　要：为解决某火力电厂送风机中的锻铝2A50材质动叶片断裂问题.文中利用故障树分析方法,通过现场取样、制造和运行数据监测、化学成分分析、硬度测试、金相检测及断口形貌观察等手段,对叶片断裂原因进行了综合分析.结果表明:1#叶片局部硬度偏低,强度不够,2#叶片端部外表面观察到晶界裂纹,叶片进气侧外表面存在较多颗粒物冲击凹坑,降低了叶片的抗疲劳性能;叶片在旋转离心力长期循环作用下,在进气侧外表面缺陷处过早的形成疲劳裂纹源,导致叶片失效.Two blades of forced draft fan failed in a thermal power plant. Both blades are made of novel wrought 2A50 aluminum alloys. Using the fault tree analysis,fracture of blades was studied in terms of engineering, preparation, construction and running through a process of elimination. Besides checking on the scene and collecting data, metal inspections were conducted, such as composition, micro-structure, hardness and fracture morphology. Results showed that the fatigue resistance of the two blades was suffered by low hardness for No. 1 blade and intergranluar micro-cracks for No. 2 blade,as well as pits on air inlet surface of blades. Under a long time of cyclic centrifugal pull, the fatigue crack prematurely originated on the pits of air inlet surface and propagated until the whole blade fractured.

关 键 词：送风机 锻铝叶片 疲劳 失效分析 

分 类 号：TM621.2[电气工程—电力系统及自动化]