高温塔底油浆泵叶轮断裂失效分析

针对高温塔底油浆泵使用一段时间后在开机时叶轮频繁发生断裂的现象，选择发生断裂现象较多的泵型，对可能导致叶轮断裂的各种因素，从断裂点的宏观检查到叶轮材料、硬度以及断裂点的金相组织的微观检验等方面进行了一系列试验，采用热冲击理论最新研究成果对该叶轮断裂失效原因进行了分析，结果表明，叶轮存在严重的铸造缺陷，热处理工艺出现了偏差，高温环境削弱了叶轮的强度，热冲击应力是导致叶轮断裂失效的主要原因，通过对叶轮结构、铸造工艺、热处理工艺、开机操作规程等方面的改进，基本解决了油浆泵的叶轮断裂问题．

Fracture failure analysis of high-temperature tower bottom slurry oil pump's impeller

Fracture often occurs suddenly at the start-up to the impeller of high-temperature tower bottom slurry oil pump when it has been used for a period of time. To find the cause of this phenomenon, some possible factors are considered. A series of experiments were done from the macroscopic inspection which was aimed at the breakpoints to the microscopic tests, such as material composition test and hardness measurement to the impeller. Metallurgical structure test to the breakpoints were done to the model in which this phenomenon most occurred. Thermal shock theory was also applied to the failure analysis to the impeller. The analysis and test proved that there are serious casting defect in the impeller and deviation during the heat treatment and strength reduction in high temperature environment. Among them, stress derived thermal shock were the main cause for the failure of impeller. Through the improvements in the aspects of impeller structure, casting and heat treatment process, and the operating regulation during star-up, the problem of impeller fracture has been basically solved.