采用激光诱导击穿光谱技术测定合金钢中锰和硅的含量

基于激光诱导击穿光谱(LIBS)技术定量分析多品种合金钢中锰(Mn)和硅(Si)的浓度，采用的校正方法为多元二次非线性函数定标方法。分析的钢种有普通合金钢、不锈钢、碳素工具钢等。由于不同钢种在基体组成上存在较大差异，而且钢的光谱还存在复杂的谱线重叠干扰，所以受基体效应影响严重。因此，对钢这类复杂化学体系物质的定量分析，若采用单谱线信息的校正方法会造成很多有用信息的丢失，而采用多变量的定标法会更充分利用光谱中的信息，更有效校正多基体组分的基体效应，进而提高LIBS定量分析的重复性和准确性。相比线性标准定标曲线法，测量结果的相对标准差从20%以上降低到10%以下，Mn元素测量结果的准确度提高了5倍多，Si元素提高了6倍多。

Quantitative Analysis of Mn and Si of Alloy Stseels by Laser-Induced Breakdown Spectroscopy

The concentration of Mn and Si in different kinds of steels was determined by laser-induced breakdown spectroscopy (LIBS). The multivariate quadratic nonlinear function was adopted for calibration. Samples including common alloy steels, stainless steels and carbon tool steels were analyzed. The matrix effect was serious because of large difference in compositions of different kinds of steels and strong line overlaps in steel spectra. Therefore, the common calibration methods that only use one analytical line to calibrate the complex chemical compositions of alloy steels will lose much information. The multivariate calibration methods, however, can utilize more information of spectra, successfully reduce the matrix effect and improve the measurement repeatability and accuracy of LIBS. Compared with the common calibration method based on one analytical line, the relative standard deviation was reduced from above 20% to below 10%, and the accuracy was increased by more than 5 times for Mn and more than 6 times for Si.