Rapid online analysis of trace elements in steel using a mobile fiber-optic laser- induced breakdown spectroscopy system

A mobile fiber-optic laser-induced breakdown spectrometer (FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube. Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models. The R ² factors of the calibration curves were all above 0.99, except for Cu, indicating the elements’ strong self-absorption effect. Five special steel materials were rapidly detected in the steel mill. The average absolute errors of Mn, Cr, Ni, V, Cu, and Mo in the special steel materials were 0.039, 0.440, 0.033, 0.057, 0.003, and 0.07wt%, respectively, and their average relative errors fluctuated from 2.9% to 15.7%. The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems, but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.