R26高温合金螺栓断裂原因  

Reasons for R26 high temperature alloy bolt fracture

作　　者：孙雄[1] 杨超[1] 石仁强 SUN Xiong;YANG Chao;SHI Renqiang(Jiangsu Frontier Electric Technology Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]江苏方天电力技术有限公司,南京211102

出　　处：《理化检验（物理分册）》2024年第9期61-64,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某机组汽轮机高压导气管法兰固定用R26高温合金螺栓发生断裂现象。采用宏观观察、化学成分分析、金相检验、力学性能测试、扫描电镜及能谱分析等方法对螺栓断裂的原因进行分析。结果表明:螺栓原材料中Ti元素含量偏高,使材料中产生点状夹杂析出物,经热轧加工后,形成了带状组织,造成了螺栓的高温性能下降、硬度变大,螺栓长期在高温环境下服役,最终发生了脆性断裂。The R26 high temperature alloy bolt used to fix the flange of the high pressure air duct of a steam turbine unit fractured.The causes of bolt fracture were analyzed using macroscopic observation,chemical composition analysis,metallographic examination,mechanical property testing,scanning electron microscopy,and energy spectrum analysis.The results show that the high content of Ti element in the raw material of the bolt resulted in the formation of point like inclusions and precipitates in the material.After hot rolling processing,the banded structure was formed,causing a decrease in the high-temperature performance and an increase in hardness of the bolt.The bolt served in a high temperature environment for a long time and eventually experienced brittle fracture.

关 键 词：R26高温合金螺栓 带状组织 脆性断裂 硬度 析出相 

分 类 号：TB31[一般工业技术—材料科学与工程] TG115.2[金属学及工艺—物理冶金]