Feasibility Investigation for Online Elemental Monitoring of Iron and Steel Manufacturing Processes using Laser-Induced Breakdown Spectroscopy

Abstract

The metallurgical industries are very important for social development. In order to improve the metallurgical techniques and quality of products, the real-time analysis and monitoring of iron and steel manufacturing processes are very significant. Laser-induced breakdown spectroscopy (LIBS) has been studied and applied for the contents measurement of iron and steel. In this paper, the remote open-path LIBS measurement was studied under different sample temperature, lens to target distance (LTD), sample angle conditions to clarify its online measurement features. The 3D profile measurement system of parallel laser beam fringes projection was also developed to measure the sample profile at different sample temperature. The measurement results demonstrated the robustness of remote open-path LIBS system and 3D profile measurement system. However, the correction is necessary to enhance the detection ability of LIBS online measurement. In order to improve the precision and accuracy of real-time elemental measurement, an innovative co-axial laser beam measurement system combining LIBS and 3D profile techniques is proposed to automatically adjust the focus unit and measure the sample components. The further study of this promising method will be developed for online application of iron and steel manufacturing processes. KEY WORDS: laser-induced breakdown spectroscopy; 3D profile; remote measurement; iron and steel manufacturing processes.

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…There have therefore been several applications reported of the LIBS analysis of steel at the production line . An example of this was a paper entitled “feasibility investigation for on-line elemental monitoring of iron and steel manufacturing processes using LIBS”, published by Wang et al 17 The paper studied the effects of different sample temperatures, lens to target distance and the angle of analysis. The Q-switched Nd:YAG laser operating conditions and the spectrometer used were discussed in detail with the aid of a schematic diagram and the method validated by the use of numerous standard steel samples.…”

Sample Temperature Effect on Steel Measurement Using SP-LIBS and Collinear Long-short DP-LIBS

“…In LIBS process, the emission intensity is a function of concentration of species and plasma temperature. 33) Due to the plasma and plasma temperature are not stable and uniform, the emission intensity for each element will fluctuates with plasma temperature, which will affect the accuracy of quantitative analysis. Therefore, a plasma temperature correction method was proposed to improve the quantitative analysis capability of LIBS signal by our group, which was described in the previous work.…”

Control of Laser Focal Point by Using an Electrically Tunable Lens in Laser-induced Plasma Optical Emission Spectrometry

“…For such a purpose, Noll et al suggested an experimental apparatus of LIBS including an auto-tuning system of the laser focal position to detect the emitted radiation from the specimens. 4) More recently, a group of Deguchi published a LIBS measuring system for online elemental monitoring of a steel manufacturing processes, 5) and also reported a LIBS analysis of manganese in steel samples under high temperature atmosphere. 6) A LIBS apparatus, which has a complicated optical system so that the emitted radiation as well as the laser beam can be simultaneously focused just on a sample surface, has been commercially available for the fast in-line analysis.…”