由单个小冲杆蠕变曲线求解材料蠕变性能参数的方法

发布时间：2018-07-01 12:43

本文选题：小冲杆试验 + 蠕变　；参考：《华东理工大学》2015年博士论文

【摘要】：电力、石化行业诸多高温高压设备的蠕变性能需要进行评定。对在役压力容器进行取样评估时,传统的单轴蠕变试验方法所需要的试样尺寸大、不方便从在役设备上直接取样,为了保证企业产线在正常运行情况下,能够对在役设备进行取样并进行蠕变性能的预测及分析,不少研究人员提出了多种微试样的蠕变试验方法,例如,压痕蠕变试验、圆环蠕变试验、小冲杆蠕变试验、对常规试样进行等比例缩小的微试样蠕变试验等无损或者微损的蠕变试验方法,其中小冲杆蠕变试验备受国内外研究人员的关注。本文基于电厂用高温CrMo用钢对小冲杆蠕变试验装置及小冲杆蠕变性能参数的获取方法进行了相关的研究。研制了新型的小冲杆蠕变试验装置；提出了获取小冲杆蠕变性能参数的方法；研究了小冲杆蠕变试验载荷与应力转换关系式的获取方法；提出了小冲杆蠕变试验寿命分析的新方法,本文主要工作及研究成果如下：1)通过国内外的小冲杆蠕变试验装置的研究分析,研制出了一套新型的小冲杆蠕变试验装置,与现有的小冲杆蠕变试验装置相比,该装置具有操作方便、获得数据准确、结构简单等优点。并对研制出的小冲杆蠕变试验装置进行了重复性试验以及可靠性试验,表明该小冲杆蠕变试验装置能够满足小冲杆蠕变试验的需要。2)提出利用反向有限元求解小冲杆蠕变性能参数的方法。利用单个小冲杆蠕变试样的时间位移曲线结合有限元分析软件获得材料的Norton性能参数,该方法便捷有效,能够省去繁琐的长时间的小冲杆蠕变性能试验。同时进行了不同载荷的小冲杆蠕变,验证了本文提出方法的可靠性。3)在利用反向方法获得小冲杆蠕变性能参数的基础上,提出利用单个小冲杆蠕变试验曲线结合有限元分析软件,获得小冲杆蠕变试样的载荷与应力之间的关系式,结果表明,该方法可以更为便捷直接地获得小冲杆蠕变试验载荷与等效应力的关系,同时也避免了小冲杆蠕变试验载荷与等效应力之间的经验关系转化所引起的分析误差。4)在反向方法得出小冲杆蠕变性能参数以及载荷与应力研究结论的基础上,提出了利用单个小冲杆蠕变试验曲线获取小冲杆蠕变试样持久寿命的方法,并通过小冲杆蠕变试验及常用的持久寿命分析方法(Dorm、Monkman-Grant)对本文提出的新方法进行了验证,结果表明本文的方法简单有效。
[Abstract]:The creep properties of many high temperature and high pressure equipments in power and petrochemical industry need to be evaluated. In the process of sampling and evaluation of in-service pressure vessels, the traditional uniaxial creep test method requires a large sample size, which is not convenient for direct sampling from in-service equipment, in order to ensure that the production line of the enterprise is in normal operation. Many researchers have put forward a variety of creep test methods for microspecimen, such as indentation creep test, ring creep test, small impact bar creep test. Non-destructive or micro-damage creep test methods such as creep test of microspecimen with equal proportion are carried out on conventional specimens. Among them, creep test of small punching rod has attracted much attention from researchers at home and abroad. Based on the high temperature CrMo steel used in power plant, the creep test device of small impact rod and the method of obtaining creep performance parameters of small punch rod are studied in this paper. A new type of creep test device for small punch rod is developed, a method for obtaining creep performance parameters of small punch rod is put forward, and the method for obtaining the relationship between creep test load and stress transformation of small punch rod is studied. A new method of life analysis for creep test of small punch rod is proposed. The main work and research results are as follows: 1. Through the research and analysis of creep test equipment of small impact rod at home and abroad, a new set of creep test device for small punch rod is developed. Compared with the existing small punch bar creep test device, this device has the advantages of convenient operation, accurate data acquisition, simple structure, and so on. The repeatability test and reliability test were carried out for the creep test device of small punching rod. It is shown that the creep test device can meet the need of creep test of small punch rod. 2) the method of solving creep performance parameters of small punch rod by reverse finite element method is put forward. The time displacement curve of creep specimen of a single small punch bar and the finite element analysis software are used to obtain the Norton performance parameters of the material. The method is convenient and effective and can save the tedious long time creep performance test of the small punch rod. At the same time, the creep of small impact bar with different loads is carried out, and the reliability of the proposed method is verified. 3) on the basis of using reverse method to obtain creep performance parameters of small impact bar, The relationship between load and stress of creep specimen of small punch bar is obtained by using creep test curve of single small punch bar and finite element analysis software. The results show that, The relationship between creep test load and equivalent stress can be obtained more conveniently and directly by this method. At the same time, the analysis error caused by the transformation of the empirical relationship between the creep test load and equivalent stress of the small punch rod is avoided. 4) on the basis of the conclusion of the reverse method, the creep performance parameters and the load and stress of the small punch rod are obtained. A method for obtaining the rupture life of creep specimen of small impact bar by using creep test curve of single small punch bar is proposed. The new method is verified by creep test of small punch bar and Dormon Monkman-Grant method. The results show that the method is simple and effective.
【学位授予单位】：华东理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH49;TG115.57

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