DP-LIBS For The Research And Implementation Of Carbon Content Detection In Iron-based Alloy

The real-time monitoring of carbon increase at every link of steel, making and adjusting steel process play a very important role in improving production efficacy and quality of products. LIBS technique has been widely used in many fields, it is suitable for metallic elements and not for non-metallic elements due to its bad effect. While the DP-LIBS is possible to detect the weak signal of carbon in iron-based alloy with improved ablation efficiency, spectral line intensity and element detection limitation.The paper first gives a brief description of the technological background and the status quo of DP-LIBS. Then different aspects of physical processes in optical emission spectroscopy are analyzed in equilibrium and non equilibrium conditions. A very simple but accurate method to calculate the partition function of atomic species based on the reduction of the energy level pattern to a three grouped levels system is introduced. Collisional-radiative models are illustrated with different examples emphasizing the coupling of the electron energy distribution function with excited states population and radiation. Finally, models including fluid dynamic equations to describe the LIBS plume expansion in both one and two space dimensions are discussed, showing that these methods can be used to qualitatively rationalize double pulse experiments and, to some extent, to reproduce experimental results. While laser-induced breakdown spectroscopy (LIBS) is an attractive technique because of its basic simplicity with little or no sample preparation and ability to be performed under standard Earth atmosphere, there we are interested in performing LIBS under non-standard pressures and with surrounding atmospheric gases other than air. Altering the atmospheric pressure can dramatically change the observed LIBS spectra, such as greatly improving the resolution, signal intensity, and overall signal-to-noise ratio by judicious choice of pressure and gas composition. In order to identify trace carbon in the iron-based alloy, the signal detection of carbon was investigated with double-pulse laser-induced breakdown spectrometry (DP LIBS) in collinear configuration. We studied the conventional method for DP LIBS, including inter-pulse delay and the combination of laser wavelengths. Besides, we discussed the relation between the target’s thermal diffusivity and observed electron temperature and found that DP-LIBS for carbon content detection in iron-based Alloy mainly enhanced the signal intensity and plasma stability and persistence.