Study On Multi-elements Detection Of Solid And Molten Carbon Steel By LIBS

On-line element content detection is one of the key techniques to ensure the quality of iron and steel metallurgy. Until now we mainly adopt the offline analytical methods, such as photoelectric direct reading spectroscopy, X-ray fluorescence spectroscopy, inductively coupled plasma-atomic emission spectroscopy and flame atomic absorption spectrometry, etc. These methods need to pretreat the samples, such as crushing, grinding and surface treatment, and then send to the laboratory for analysis. These methods are time-consuming and low efficient. Laser Induced Breakdown Spectroscopy (LIBS) is a detection technique using pulsed laser to heat the sample into plasma state from which the element content is detected by the spectrum of the plasma. The advantage of LIBS is the capacity of remote detection, which is very suitable for the contentment of steel. We use a LIBS system that has been built in our laboratory for detection of element content of steel. The system consists of a Q-switched Nd:YAG laser (repetition rate10Hz,wavelength1064nm, pulse length10ns, pulse energy about120mJ), high frequency induction furnace (temperature1600℃), spectrometer (wavelength range186-310nm, spectral resolution0.1nm), laser focusing and spectral signal collecting system. The main work of this paper includes:1. The quantitative analysis of C, Cr, Mn, Si, S, Cu, Ni of solid and molten carbon steel in the atmospheric environment has been made. Establish the calibration curve by the use of internal standard calibration method.2. The calibration curves with different time delay are compared and the best delay times for each element are found.This paper is to realize the high precision analysis of the quantitative analysis of C, Cr, Mn, Si, S, Cu, Ni of solid and molten carbon steel, and to fix the optimized delay time and calibration curve for each element. Get the best delay time and calibration curve of each internal standard line pair.