权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Evaluation of Creep-Fatigue-Environment Interaction Based on Mechanical Response

基于机械响应的蠕变-疲劳-环境相互作用评估

基本信息

批准号：
61460085
负责人：
ASADA Yasuhide
金额：
$ 4.42万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-61460085/
关键词：
Creep-Fatigue Interaction Environmental Effect Overstress Internal Stress Back Stress Drag Stress Life Prediction Equation Time-Dependent Damage 時間非依存損傷クリープ疲労相互作用 304鋼 21 4Cr-1Mo鋼

项目摘要

Creep-Fatigue Tests were made with 304 stainless steel at 650゜C and with 2 1/4Cr-lMo steel at 550゜C in arr and vacuum of 0.1 mPa and 0.1 <mu>Pa under a wide variety of strain loading conditions. Test data of stress-strain response and fatigue properties were stored in a data base for further analyses.It was shown that the stress-strain response is independent of test environments for both steels. A measured stress is composed of the overstress and the internal stress. The internal stress of 304 steel is composed of the back stress. However, in 2 1/4Cr-1Mo steel, the internal stress is composed of the drag component and back component of the stress.The overstress and back stress of 304 steel depend upon both inelastic strain rate and strain range. However, in 2 1/4Cr-1Mo steel, the overstress is independent of these test variables. The drag stress of this steel depends upon only a strain range. The back stress depends upon the inelastic strain rate. It was shown with both steels that the back stress depends upon the cyclic strain hardening or softening behavior.The time-independent damage factor of both steels can be described with the overstress and a mean stress. Regarding the time-dependent damage factor, that of 304 steel can be described with the overstress. But that of 2 1/4Cr-1Mo steel can be described with the internal stress. Based on these results, an evaluation equation was derived for the pure creep-fatigue behavior of these two steels.Based on the above equation, the environmental effect was seperated from the creep-fatigue interaction and was abalyzed with mechanical quantities of stress and strain. It was shown that the environmental effect is mainly affected by a strain rate. An evaluation oquation was obtained with respect ot the environmental damage described with mechanical parameters.

304不锈钢和2 1/4Cr-LMO钢分别在650゜C和550゜C的ARR和0.1 Mpa和0.1&lt；Mu&gt；Pa.在各种应变载荷条件下进行蠕变疲劳试验。将应力应变响应和疲劳性能的测试数据存储在数据库中，以供进一步分析。结果表明，两种钢的应力应变响应与试验环境无关。测得的应力由超应力和内应力组成。304钢的内应力由背应力组成。然而，在2 1/4Cr-1Mo钢中，内应力由拉应力和背应力组成，304钢的超应力和背应力与非弹性应变率和应变范围有关。然而，对于2 1/4Cr-1Mo钢，过应力与这些试验变量无关。这种钢的拉应力只取决于一个应变范围。背应力取决于非弹性应变率。结果表明，两种钢的背应力均取决于循环应变硬化或软化行为，两种钢的时间无关损伤因子均可用超应力和平均应力来描述。对于时间相关的损伤因子，304钢的损伤因子可以用超应力描述。而2 1/4Cr-1Mo钢的应力可用内应力来描述。在此基础上，建立了两种钢的纯蠕变疲劳行为评价方程，并在此基础上将环境效应从蠕变疲劳交互作用中分离出来，用应力应变的力学量进行了分析。结果表明，环境效应主要受应变率的影响。得到了用力学参数描述的环境破坏的评价方程。