摘要
某燃气轮机涡轮系统用连接螺栓,试车分解检查时发现多件断裂。采用断口宏微观观察,金相组织分析,能谱分析,故障模拟验证试验等方法,对螺栓的断裂原因进行了综合分析。结果表明:失效螺栓属于沿晶脆性断裂;螺栓装配过程中使用的高温丝扣脂中的低熔点元素Pb,在一定的拉应力、温度作用下,引起晶界腐蚀损伤是导致螺栓断裂的主要原因。该研究结果对此类螺栓的使用和故障预防可提供借鉴。
Several connection bolts used in gas turbine were found to have fractured after service for a while. The fracture cause was analyzed by facture surface observation, microstructure examination, energy spectrum analysis and analog experiment. The results indicate that the fracture mode is intergranular brittle fracture. Under tensile stress and temperature effect, the low-mehing element Pb included in grease used during assembly process caused the intergranular corrosion damage, which is the main reason for the bolt fracture. The results are significant to failure analysis and prevention of the bolts.
出处
《失效分析与预防》
2012年第4期244-247,270,共5页
Failure Analysis and Prevention
关键词
螺栓
低熔点元素
沿晶
脆性断裂
bolt
low-melting element
intergranular fracture
brittle fracture
