High-resolution microanalysis of steel samples segregation based on picosecond laser-induced breakdown spectroscopy imaging

Segregation monitoring plays a crucial role in the quality control of steels, and elemental microanalysis using laser-induced breakdown spectroscopy (LIBS) can be employed as an approach in this process. In this study, we established a LIBS system utilizing a 9-ps pulsed laser operating at 355 nm and 35 Hz repetition to investigate steel segregation. Successful analysis of Aluminum (Al), Copper (Cu), and Manganese (Mn) segregation in steels was achieved. The LIBS mappings with a spatial resolution of 2 μm demonstrated agreement with results obtained from Electron Probe Microanalysis (EPMA), thereby affirming their reliability. Furthermore, by employing an even higher spatial resolution of 1 μm, fine results could still be acquired through LIBS on a steel area of 100 μm². These findings demonstrate the effectiveness of ps-LIBS for resolving elemental segregation and suggest its potential as an alternative tool for steel inspection.