Development of Alloy Design and Evaluation Systems for High Temperature Materials Based on Non-Steady-State Creep Concept

基于非稳态蠕变概念的高温材料合金设计与评价系统开发

基本信息

批准号：
07555653
负责人：
MARUYAMA Kouichi
金额：
$ 2.43万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555653/
关键词：
Structural Materials High Temperature Creep Long Term Properties Alloy Design Constitutive Creep Equation Creep Defects Materials Database Deformation Mechanism

项目摘要

Long term creep properties of high temperature materials are evaluated from short term creep tests. The objective of the present research is to improve ways of formulation of short term creep data and evaluation of long term properties. The results are summarized as follows :1.Improvement of rupture life prediction : The following creep equation was proposed based on OMEGA method :epsilon=(1/OMEGA){In(1+zetat)-In(1-etat)} (1)where epsilon is the creep strain, t is the time, and OMEGA, zeta and eta are material constants. This equation can predict more accurate rupture life from shorter creep tests.2.Relevant condition of short term tests : Short term test conditions are selected based on deformation mechanism maps so that creep mechanism does not change from service condition of engineering plant. Long term creep data of 2.25Cr-lMo steel was analyzed to clarify how to select the test conditions. It was found that deformation mechanism maps presently available have several misunderstandings. A correct mechanism map of the steel was proposed.3.Examination of prediction methodology : Several methods proposed for rupture life prediction were examined by long term creep date over 10^5h. More relevant methods were suggested among the proposed methods. Another finding to be mentioned is the concept of inherent creep strength. Namely, all the low alloy steels gives similar creep rupture strength when test duration is long enough.4.Correlation between microstructural degradation and creep life consumption : Degradation of martensitic lath structure was studied in detail during creep of martensitic steels. A linear relation was found between relative growth of lath width and creep strain. A nondestructive life assessment method was proposed based on the linear relation.5.Modification of database system : An object-oriented database system was modified to the form applicable to creep data.

高温材料的长期蠕变特性通过短期蠕变测试评估。本研究的目的是改善短期蠕变数据的制定方式和长期特性的评估。结果总结如下：1。破裂寿命预测：基于欧米茄方法提出了以下蠕变方程：epsilon =（1/omemega）{in（1+zetat）-in（1-etat）-in（1-etat）}（1）（1），epsilon是蠕变是蠕变，t是蠕变，t是时间，t是时间，ZETA和OMEGA，ZETASASASASASASASASASASASASASASASASASA和ETA。该方程式可以预测较短的蠕变测试中的更准确的破裂寿命。2。短期测试的条件：基于变形机制图，选择短期测试条件，以使蠕变机制不会从工程工厂的服务条件下变化。分析了2.25CR-LMO钢的长期蠕变数据，以澄清如何选择测试条件。发现目前可用的变形机制有几种误解。提出了钢的正确机制图。3。预测方法的研究：通过长期蠕变日期超过10^5H，研究了一些用于破裂生命预测的方法。在提出的方法中提出了更多相关的方法。要提到的另一个发现是固有的蠕变力量的概念。也就是说，所有低合金钢在足够长的时间时都会产生类似的蠕变破裂强度。4。在马氏体钢蠕变期间，详细研究了微观结构降解与蠕变寿命消耗之间的相关性：Martensenitic板条结构的降解。在板条宽度的相对生长和蠕变应变之间发现线性关系。基于线性关系提出了一种非破坏性生活评估方法。5。数据库系统的修改：将面向对象的数据库系统修改为适用于蠕变数据的形式。