Element Analysis Of Alloy Steel By Laser-Induced Breakdown Spectroscopy

In this paper, element analysis methods of steel are introduced, and then a new method of Laser-induced breakdown spectroscopy (LIBS) is introduced, which is fit for high speed analysis of steel. The progress and applications in several fields of LIBS technique are summarized.The dependence of different experimental parameters on single-pulse LIBS (SP-LIBS) spectral intensity and signal to background ratio of solid alloy steel standard sample were investigated. Furthermore, we analyzed the same samples by using orthogonal pre-ablation dual-pulse LIBS(DP-LIBS). Compared with SP-LIBS, enhancement of spectral intensity of nine trace elements in alloy steel is obtained, the enhancement is related to pre-ablation laser wavelength and interpulse delay time. Spectral enhancement of Cv I427.48nm reached67times in1064nm/1064nm DP-LIBS and its mechanism is analyzed. Based on quantitative analysis of several trace elements in six alloy steel standard samples, calibration curve, correlation coefficient(R2) and relative standard deviation are obtained. It shows that DP-LIBS technique can increase R-and reduce RSD and then improve sensitivity and repetition of LIBS technique. The limit of detection and relative error of several trace elements are obtained. The detection limits of Cr I427.48nm and Cu I327.396nm calculated are22.3ppm and11.7ppm respectively, relative errors are all within5%range. It is demonstrated that detection precision and reliability can be enhanced by using DP-LIBS.Our studies show the excellent performance of DP-LIBS technique on increasing the accuracy, sensitivity, repetition and detection precision. The experiment results in our experiments should be useful for further research on the trace elements analysis of alloy steel and provide experimental basis for application of DP-LIBS. Quantitative analysis of nonmetal elements such as C and S in visible region is realized.