SUCCESSFUL LASER CUTTING OF STEEL PLATES

In this study, the research team examined the role played by steel composition and thermophysical properties such as solidus and liquidus temperatures, heat of oxidation, surface tension, viscosity, and thermal conductivity in laser cutting. The laboratory-produced steels investigated contained varying levels of carbon, sulfur, silicon, copper, nickel, chromium, and molybdenum, and were hot-rolled to 32-mm thick plates. The plates were blanchard-ground to 25 mm, and were shot-blasted to eliminate surface effects and roughness variability. Results showed that under these conditions, copper and nickel improved cutting performance, while chromium degraded cutting performance. On the other hand, carbon and silicon did not affect cut quality. No direct correlation was found among steel composition, laser cut quality, and thermophysical properties. However, limited confocal microscopy and EDS analysis of selected cut surfaces suggested that enrichment at the cutting front of alloying elements resistant to oxidation might play a major role in determining cut quality.