高温合金FGH 4095温度和时间依赖的单向加载蠕变本构关系  

Temperature and Time Dependent Creep Constitutive Relationship of Superalloy FGH 4095 Under Unidirectional Loading

作　　者：凌小君 郑小梅[2] 夏日 程钰锋 许金泉[1] LING Xiaojun;ZHENG Xiaomei;XIA Ri;CHENG Yufeng;XU Jinquan(School of Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Beijing Aeronautical Engineering Technical Research Center,Beijing 100076,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]北京航空工程技术研究中心,北京100076

出　　处：《力学季刊》2024年第4期961-969,共9页Chinese Quarterly of Mechanics

基　　金：国家重大科技专项(J2019-IV-0008-0076);国家自然科学基金(11772189)。

摘　　要：传统的蠕变本构关系一般是针对瞬态、稳态和加速蠕变三个阶段中的一个阶段给出的,幂蠕变是最常见的稳态蠕变本构关系.然而对于实际高温合金结构,其一个工作周期内的蠕变过程,往往是瞬态、稳态和加速蠕变三个阶段混合在一起的,并不一定会出现稳态蠕变占支配地位的阶段.因此从应用的角度看,需要一种不受常规蠕变三阶段区分限制的,可以适用于整个工作周期的长程蠕变本构关系.本文对高温合金FGH4095在530℃、600℃及700℃三种温度下进行了蠕变试验,采用分段表征的修正Θ-projection法,给出了长程蠕变本构关系的具体形式.该本构模型包含5个状态特性参数,它们是温度及应力水平依存的.为便于实际应用,本文通过几种不同温度、不同应力水平下的蠕变试验,得到了特性参数与温度、应力的拟合关系式.Traditional creep constitutive relationship is generally developed only for one of the three stages,i.e.,transient,steadystate and accelerated stages.The well known power law creep relationship is only a typical creep constitutive model for steady creep stage.In high temperature allloy structures,however,the well known three stages of creep are usually mixed up in one working cycle,and the steady-state creep stage may not be dominant and even not observable.Therefore,from the perspective of engineering application,it is necessary to develop a long term creep constitutive relationship which can be applied for actual working loadings,without the limitation of traditional creep stage distinguishments.In this paper,creep tests of high temperature alloy FGH4095 are carried out at 530℃,600℃and 700℃.From the analyses of experimental results,a modifiedΘ-projection method has been proposed,and the detailed long-term creep constitutive relationship has been developed.This model contains 5 creep state parameters,which are dependent on both temperature and stress level.For the convenience of practical application,creep tests at several different temperatures and stress levels are conducted,from which the empirical relationships of the creep state parameters depending on the temperature and stress level have been obtained.

关 键 词：高温蠕变 蠕变曲线 本构关系 长程蠕变 温度依存性 

分 类 号：TG132.3[一般工业技术—材料科学与工程] V252[金属学及工艺—合金]