高温复杂疲劳工况下10%Cr钢寿命特性

汽轮机转子等高温零部件在工作环境下经常受到高低周复合疲劳载荷,高低周疲劳交互作用时,机组寿命会大幅下降。为评价高温复杂疲劳工况下转子钢的寿命特性,分别进行了低周疲劳实验、高周疲劳实验及高低周复合疲劳实验,并分析了各实验工况下的寿命特性。通过对应变与寿命的关系进行分析,发现高低周复合疲劳应变幅比与寿命比在双对数坐标下呈幂函数关系,并以此提出一种研究高低周复合疲劳寿命的新方法。

Study on Life Characteristics of 10%Cr Steel under High Temperature and Complex Fatigue Conditions

As the high temperature equipment, the turbine rotor and other components are often subjected to combined high and low cycle fatigue loading in the working environment. When the high and low cycle fatigue interacts, the life of the unit will be reduced greatly. In order to evaluate the life characteristics of rotor steel under high temperature and complex fatigue conditions, low cycle fatigue experiment, high cycle fatigue experiment, and combined high and low cycle fatigue experiment were conducted respectively. Moreover, life characteristics under various experimental conditions were analyzed. Based on the analysis of the relationship between strain and life, it was found that the combined high and low cycle fatigue strain amplitude ratio and life ratio have a power function relationship in double logarithmic coordinates. Therefore, a new model for studying combined high and low cycle fatigue life was proposed.