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目前有许多机械设备,如压力密器、汽轮机、燃气轮机和加热设备中的传输机械等,都是处在高温条件下工作。对于这些机械的零部件,无论在设计方法、材料选择或失效分析方面都与常温情况不同,需要使用蠕变设计来解决。一、金属材料的蠕变特性金属材料在恒温度和恒应力的长期作用下,随时间的延长而缓慢地发生塑性变形的现象,称为蠕变。蠕变可以在小于材料屈服极限的应力下发生,并且只有达到一定的温度时才变得显著。对于各种材料的蠕变温度约为0.3T_m左右,T_m为金属材料的熔化温
At present there are many mechanical equipment, such as compressors, steam turbines, gas turbines and heating equipment in the transmission machinery, are working in high temperature conditions. For these mechanical components, the design method, material selection or failure analysis are different from the normal temperature, the need to use creep design to solve. First, the creep properties of metallic materials Metal materials in the long-term role of constant temperature and constant stress, with the extension of time and slowly plastic deformation phenomenon, known as creep. Creep can occur at stresses less than the yield limit of the material, and only becomes significant when a certain temperature is reached. For various materials, the creep temperature is about 0.3T_m, T_m is the melting temperature of the metal material