小冲杆蠕变关联系数的确定及其寿命预测的运用

发布时间：2018-04-04 04:00

本文选题：关联系数　切入点：小冲杆蠕变测试　出处：《华东理工大学》2017年硕士论文

【摘要】：高温服役设备的力学性能评估及剩余寿命预测对保障运行安全、降低人员伤害和减小经济损失具有重要意义。小冲杆蠕变测试技术作为一种微损测试方法可以对设备本身微损取样而不需要修复,因而被认为是一种最具应用前景的测试方法。目前科学研究与工程设计都使用常规试验方法来获得材料的蠕变力学性能,怎样使得小冲杆蠕变测试方法获得的材料蠕变性能具有和常规蠕变试验结果一样的参考价值是研究的重点。2006年,欧洲标准委员会推出小冲杆蠕变测试标准,其中小冲杆蠕变关联系数被首次引入并用来关联小冲杆蠕变与单轴蠕变性能数据。作者通过研究关联系数Ksp对小冲杆蠕变与单轴拉伸蠕变的关系进行了探索,通过进行不同应力状态下的小冲杆蠕变试验与单轴蠕变试验,选用诺顿方程和多恩公式等蠕变模型来对Kp值进行研究。同时,对于获得的16Mo3蠕变断裂寿命数据,基于Monkman-Grant与Larson-Miller等预测模型,构建了小冲杆蠕变的断裂寿命与载荷的关系,并与同条件下单轴拉伸寿命预测进行了对比。论文主要获得如下结果:1)提出了一种获得小冲杆蠕变与单轴蠕变关联系数的方法,该方法与之前研究学者常用的方法相比具有更好的实际操作性。2)对于三种高温材料,通过实验获得了不同的Ksp值。根据获得的这个关联系数,可以直接将小冲杆蠕变试验结果向单轴转化。3)建立了小冲杆蠕变的Monkman-Grant与Larson-Miller寿命预测模型。通过比较小冲杆蠕变与单轴蠕变的Monkman-Grant寿命预测模型,分析了影响两者寿命预测精度的因素。
[Abstract]:The evaluation of mechanical properties and the prediction of residual life of high temperature service equipment are of great significance to ensure the safety of operation, reduce the injury of personnel and reduce the economic loss.As a micro-damage testing method, small impact bar creep testing technique is considered to be the most promising test method because it can be used to sample the micro-damage of the equipment without the need of repair.At present, both scientific research and engineering design use conventional test methods to obtain creep mechanical properties of materials.How to make the creep properties of the materials obtained by the creep test method of small punch rod have the same reference value as the results of the conventional creep tests is the key point of the study. In 2006, the European Committee of Standards introduced the creep test standard of small punch rod.Among them, the creep correlation coefficient of small punch bar is introduced for the first time and used to correlate the creep and uniaxial creep performance data of small punch rod.The relationship between creep of small punch rod and uniaxial tensile creep was studied by means of correlation coefficient Ksp. Creep tests of small punch rod and uniaxial creep test were carried out under different stress states.The creep models such as Norton equation and Dorne formula are used to study the value of Kp.At the same time, based on Monkman-Grant and Larson-Miller prediction models, the relationship between creep life and load of small impact bar is constructed and compared with the tensile life prediction of order shaft issued under the same condition for the obtained 16Mo3 creep fracture life data.In this paper, the following results are obtained: (1) A method to obtain the correlation coefficient between creep and uniaxial creep of small punching rod is proposed. This method has better practical operation than the previous methods commonly used by scholars) for three kinds of high temperature materials.Different Ksp values were obtained through experiments.According to the correlation coefficient obtained, the creep test results of small punch bar can be directly transformed to uniaxial. 3) the Monkman-Grant and Larson-Miller life prediction models of small punch rod creep can be established.By comparing the Monkman-Grant life prediction model of small impact rod creep and uniaxial creep, the factors that affect the accuracy of the two life prediction are analyzed.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB302.3

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