Simultaneous analysis of Si, Mn and Ti segregation in pig iron by laser-induced breakdown spectroscopy

There has been no effective method for detecting the element segregation of large metallic material samples so far. In this research, the newly emerging laser-induced breakdown spectroscopy (LIBS) was applied to quantitatively analyze the segregation of Si, Mn and Ti in pig iron simultaneously. The spectra lines of Si (288.16 nm), Mn (293.31 nm) and Ti (334.94 nm) were selected as the quantitative analysis spectral lines, while lines of Fe (263.58 nm, 441.51 nm, 370.79 nm) were chosen as the internal calibration lines to reduce the influence of matrix effect. The fitting correlation coefficients (R2) were 0.991 7, 0.990 3, 0.991 2, respectively, which proved the ability of LIBS in measuring the concentration of Si, Mn and Ti correctly and simultaneously. A pig iron sample from blast furnace was cut into two round iron samples, whose surface were analyzed with the help of spatial-resolved LIBS subsequently. The element maps revealed the segregation locations of Si, Mn and Ti. The maximum positive and negative segregation degree of three alloy elements was also calculated based on the analysis results of LIBS. The work in this study demonstrates the capability of LIBS for detecting the segregation of alloy elements in pig iron simultaneously. It also reveals the segregation law of alloy elements in pig iron, which is meaningful for the understanding of alloy elements transfer and distribution during solidification process.