TP347H受热面材料的激光光谱特性分析

发布时间：2018-06-21 13:40

本文选题：激光诱导击穿光谱 + 锅炉受热面　；参考：《华南理工大学》2015年硕士论文

【摘要】：随着火电厂机组向大容量、高参数发展,机组安全稳定运行显得越来越重要。锅炉作为火电厂机组的重要组成部分,它是否稳定安全运行是影响机组的重要因素。锅炉受热面在高温高压环境下长期运行,其宏观性能及微观结构会随时间推移逐渐发生变化。受热面材料使用状态的好坏已成为直接影响锅炉安全、经济运行的重要因素。对受热面材料性能的监测分析一直都是锅炉安全的重要任务。激光诱导击穿光谱技术(Laser-induced breakdown spectroscopy,LIBS)作为一种原子发射光谱技术,被广泛应用于应用医学领域、化石能源领域、土壤分析、大气污染防治等领域。激光诱导击穿光谱技术具有分析快速、适合任何样品形态、无需样品预处理、以及多元素同时测量等优点,同时基体效应是该技术的特点之一。本论文充分利用LIBS技术的基体效应的特点,从等离子体光谱信息反向分析材料基体的特性,利用激光诱导击穿光谱技术对锅炉现场受热面TP347H材料进行检测分析,致力于分析TP347H的激光光谱特性和不同服役状态TP347H材料的预测。论文首先阐述分析了本文的研究背景和意义,总结了传统受热面材料失效分析技术。对激光诱导击穿光谱技术进行了简要介绍,重点分析国内外LIBS技术在金属领域的研究现状。论文对比分析TP347H受热面材料打磨前后的光谱特性,观察激光脉冲作用于不同表面状态的散点图变化趋势的差异情况,深入分析打磨与未磨部位等离子体特性的差异。结果发现未磨部位等离子体光谱元素绝对强度、等离子体温度、电子密度以及样品烧蚀坑都比打磨部位的参数大。论文随后对比分析了不同服役状态TP347H的光谱特性,深入探索不同服役状态TP347H与等离子体参数的联系。以样品晶粒度等级为指标,分析不同等离子体参数与晶粒度等级的关联性。最后结合化学计量学分析方法——主成分分析法分析不同服役状态TP347H材料光谱数据。结果发现,选择合适的输入数据可以提高主成分分析法的区分能力,表明了主成分分析法适用于区分不同服役状态的材料。最后,对全文进行了总结概括,提出了本文的创新点,并对激光诱导击穿光谱技术应用于锅炉受热面金属材料提出了进一步工作建议。
[Abstract]:With the development of power plant units with large capacity and high parameters, the safe and stable operation of the units becomes more and more important. Boiler is an important part of thermal power plant, whether it is stable or safe operation is an important factor affecting the unit. The macroscopic performance and microstructure of boiler heating surface will change gradually with time when it runs under high temperature and high pressure environment for a long time. The quality of heating surface material has become an important factor directly affecting boiler safety and economic operation. Monitoring and analysis of heating surface material performance is always an important task of boiler safety. Laser-induced breakdown spectroscopy (LIBS), as an atomic emission spectroscopy, has been widely used in the fields of medicine, fossil energy, soil analysis, air pollution prevention and so on. Laser induced breakdown spectroscopy has the advantages of fast analysis, suitable for any sample morphology, no sample pretreatment, and multi-element simultaneous measurement. The matrix effect is one of the characteristics of the technique. In this paper, the characteristics of matrix effect of Libs technology are fully utilized, the characteristics of material matrix are analyzed in reverse from plasma spectrum information, and the material TP347H of boiler field heating surface is detected and analyzed by laser induced breakdown spectroscopy. The laser spectral characteristics of TP347H and the prediction of TP347H materials in different service states are analyzed. Firstly, the research background and significance of this paper are analyzed, and the traditional failure analysis technology of heating surface materials is summarized. The laser induced breakdown spectroscopy (LIBS) is briefly introduced, and the research status of LIBS in metal field at home and abroad is analyzed. The spectral characteristics of TP347H heated surface before and after grinding were compared and analyzed, and the difference of the variation trend of the scattered plot of laser pulse acting on different surface states was observed, and the difference of plasma characteristics between polished and unground parts was analyzed in depth. The results show that the absolute intensity of plasma spectral elements, plasma temperature, electron density and sample ablation pit are larger than those of grinding site. The spectral characteristics of TP347H in different service states are analyzed and the relationship between TP347H and plasma parameters is discussed. The correlation between the plasma parameters and the grain size grade was analyzed with the grain size grade of the sample as the index. Finally, the spectral data of TP347H materials with different service states were analyzed by principal component analysis (PCA), a chemometrics analysis method. The results show that the ability of PCA can be improved by selecting appropriate input data, which indicates that PCA is suitable for distinguishing materials with different service states. Finally, the paper summarizes and summarizes the full text, puts forward the innovation of this paper, and puts forward further work suggestions for the application of laser induced breakdown spectroscopy technology in boiler heating surface metal materials.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM621;TN24

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