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本文目的是建立大型熔铸涡轮盘的疲劳蠕变交互作用下的第一类断裂特征图,为此先测定了恒最大应力下的高温疲劳蠕变断裂寿命曲线,称为FC—N_f曲线,它们既不同于纯疲劳的S—N曲线,又不同于纯蠕变断裂曲线,而是二者的综合。根据寿命对应力的不同依赖关系可以把曲线分成F、C与FC三区。根据断裂机构的理论分析与断口观察,又存在着五个不同断裂机构区。在宏观与微观分析相结合的基础上建立了第一类断裂特征图。它提供了关于断裂机构与寿命资料。据此讨论交互作用的几种特征。采用竞争模型与积累模型可以表示疲劳蠕变交互作用的本质。
The purpose of this paper is to establish the first type of fracture characteristics under the fatigue-creep interaction of a large-scale cast turbine disk. For this purpose, the high-temperature fatigue creep rupture lifetime curves under constant maximum stress are measured and called FC-N_f curves. Unlike pure fatigue S-N curve, but also different from the pure creep rupture curve, but the combination of the two. According to the different life span of the stress dependence of the curve can be divided into F, C and FC three districts. According to the theoretical analysis of fracture mechanism and fracture observation, there are five different fracture mechanism areas. Based on the combination of macroscopical and microscopic analysis, the first type of fracture characteristics is established. It provides information on the fracture mechanism and life expectancy. Here are some characteristics of the interaction. The competition model and accumulation model can represent the essence of the interaction of fatigue creep.