【作者】 张亚明； 姜胜利； 郭宏；

【Author】 Zhang Yaming;Jiang Shengli;Guo Hong;Institute of Metal Research,CAS;Jilin Zhengguang Safety Technology Ltd.;

【机构】 中国科学院金属研究所； 吉林省正光安全科技有限公司；

【摘要】 某热电厂1号汽轮机主汽门高温螺栓发生断裂失效,通过宏观断口、化学成分、金相组织分析以及硬度、冲击功等力学性能检验等,对高温螺栓的断裂事故进行了综合分析。结果表明,螺栓在长期高温工作条件下,沿晶界析出网状碳化物,硬度增加,冲击功降低,材料脆化,加上螺纹根部的应力集中,使其不能满足正常工况下服役的强韧性要求而发生的脆性断裂。更多还原

【Abstract】 Focusing on the fracture of high-temperature bolt in the main stop valve of no.1 turbine in a thermal power plant,comprehensive analysis was carried on by macro morphology,chemical composition analysis,metallographic examination and mechanical properties such as hardness and impact test.The results show that for the bolts under long term service at high temperature,carbide network precipitated along the grain boundary,hardness increased,impact energy reduced showing embrittlement,and thread root stress concentrated,resulting in that they could not meet the strong toughness requirement of the service condition thus brittle fracture occurred.更多还原