【作者】 郭伟；

【导师】 赖万昌；

【作者基本信息】 成都理工大学 ， 核技术及应用， 2008， 硕士

【摘要】 铁合金是钢铁冶炼过程中重要的添加剂,其组分直接影响着钢铁产品的质量,因此对铁合金化学成分进行快速、准确分析是非常重要的。采用X射线荧光分析方法对于铁合金分析具有分析速度快、检测范围广、结果稳定可靠等优点,受到了科研和生产人员重视。本文采用便携式XRF分析仪开展铁合金主元素的快速分析研究,重点讨论了铬铁、锰铁、镍铁和钨铁合金样品的分析方法和结果。论文取得的主要成果有:1)基于激发源的初级射线为一平行射线束射向样品表面,并且试样表面平滑、均匀并对X射线荧光为无限厚,同时计算出来的X射线荧光强度为不含背景和谱线重叠的净强度这一基本假设,建立了二元样品特征荧光的计算模型,构建了单能、多能激发时的一次荧光和二次(次级)荧光强度的计算公式,探讨了二元样品中元素含量与荧光计数率之间函数关系的理论方程,定量地描述元素间基体效应的影响,为实验中基体效应校正方法的选择提供了理论依据。2)对比分析了试样制备技术中的粉末压片法和熔融法的优缺点,最终选择采用粉末压片法,同时考虑颗粒度效应及对策,配制四个系列高中低不同含量的铁合金实验样品若干;分析待测量的铁合金元素组合和元素含量变化的特点,并对元素之间的吸收增强效应作研究,结合测试结果,针对样品的组分情况,提出基体效应的实用性校正方法。3)对部分国家标准样品、部颁标准样品和自配的样品进行XRF分析,采用多种基体效应校正方法进行对比,验证了基体效应校正模型,其中铬铁样品中Fe和Cr含量的平均相对误差分别为0.96%和0.99%,锰铁样品中Fe和Mn含量的平均相对误差分别为0.68%和0.34%,镍铁样品中Fe和Ni含量的平均相对误差分别为0.20%和0.79%,钨铁样品中Fe含量的平均相对误差为2.02%,分析结果达到生产要求;提出含量型计算公式的新模式,并在锰铁样品中Mn和Fe的分析中获得成功。4)建立了二元比例法分析二元样品的数学模型,并对采用二元比例法定量分析二元样品中元素含量结果准确度的影响因素进行探讨,实践表明:与回归法相比较,二元比例法可有效降低样品的表面形态、照射面积、位置以及样品的制备条件等物理形态不一致对分析结果的影响。5)采用C#语言,在Microsoft visual studio 2005开发环境下,完成了铁合金牌号自动模糊识别模式及相关程序的开发,初步实现了铁合金牌号的模糊识别。研究表明:采用便携式X荧光分析仪器并且采用放射性同位素源激发方式具有快速现场等特点;将便携式IED-2000P型X荧光分析仪应用于铁合金分析并建立相关的分析方法,获得了大量的研究数据,为今后开展更广泛的研究与应用奠定了良好的基础,同时对于拓展该类仪器的应用领域有指导意义。更多还原

【Abstract】 Ferroalloy is a very important additive in iron and steel smelting process.The component of ferroalloy has great influence on the quality control of steel products.It’s very important to analyze the components of ferroalloy rapidly and accurately. Ferroalloy analysis by the X-ray fluorescence analysis features fast analysis,wide detecting range and reliable results.Several concerned research workers have paid attention to this technology.This paper is a summary of the studies of the X-ray fluorescence analysis technique on ferroalloy based on the conditions by portable X-ray fluorescence analyzer,emphatically discusses on the analysis methods and results of ferrochrome,ferromanganese,ferronickel and ferrotungsten samples.Including:1)Based on the hypothesis that the homogeneous specimen with smooth surface, infinite thick to characteristic X-rays irradiated under the parallel primary radiation of isotope source,meanwhile,the calculated X ray fluorescence intensity is net intensity without the influence of the background and the spectral overlap,the author establishes the fluorescence intensity model of binary samples.The model includes theoretical equations for the calculation of the first and the secondary fluorescence irradiated by single energy and multi-energy rays and the equations of the relationships between the element content and its fluorescence count.These equations can describe the matrix effect and other effects quantitatively,which provide theoretical basis for choosing method of correcting matrix effect during the practical experiment.2)Based on the comparative analysis of the advantages and disadvantages of the powder method and the Fusion Method,the author got several ferroalloy samples of four series by using powder method,with the effect of particle size and its countermeasure considered simultaneously.After the study on the analysis of the characteristics of element association and the range of element content,with its absorption and enhancement effects considered simultaneously,the author got several ferroalloy samples of four series with different components by using powder method. Combined with the analysis results and the characteristics of element association and the range of element content,the author completed to put forward the practical method of correcting matrix effect determination.3)The author completed the XRF of the national standard samples、the ministry standard samples and self-made samples,and verified models of correcting matrix effect on the basis of the comparative analysis of analysis results.The results show that its average absolute errors in testing the contents of Fe and Cr in ferrochrome samples are 0.96%and 0.99%;the average absolute errors in testing the contents of Fe and Mn in ferromanganese samples are 0.68%and 0.34%;the average absolute errors in testing the contents of Fe and Ni in ferronickel samples are 0.20%and 0.79%,while the average absolute errors in testing the contents of Fe in ferrotungsten samples is 2.02%. The results analyzed are satisfactory for production demands.The building new content type calculatingmodel was applied to achieve success in the analysis of ferromanganese samples.4)The results based on the establishing mathematical model to analyze the binary samples indicates that the binary ratio technique can lower the influence to the analysis results from the differences of the samples’ surface morphology,irradiation area,the position of samples and the preparation,conditions of samples effectively,compared with the regression methods.5)By using the C# language under the Microsoft visual studio 2005 development environment,the author completed the design of the program to auto-ambiguous identify the ferroalloy’s grade,primary implementation of auto-ambiguous identification of ferroalloy’s grade was reached.The research shows that ferroalloy analysis by portable X-ray fluorescence analyzer and irradiated by radioisotope source features fast analysis,in site,etc.Based on the application of the the IED-2000P type portable X-ray fluorescence analyzer to ferroalloy analysis and the corresponding analysis method established,a mass of research data was got,it can provide a basis for further study.Meanwhile,the research results had some degree of guiding significance to broad the application sphere of this kind of instrument.更多还原