CO 2 laser beam cutting of steels: Material issues

Laser beam cutting and its advantages along with its relevance to worldwide trends in manufacturing are introduced. Results of efforts to identify material-related factors that render steel suitable for laser cutting are described. Key material requirements for both hot-strip and discrete plate products have been summarized using data collected over several years based on anecdotal information as well as experimental results. It has become clear that near-zero residual stresses and a minimum level of residual elements (Cu, Ni, and Cr) are necessary to obtain clean pierces and consistent cut quality in thick (20–25 mm) plates, in both as-rolled and as-shot-blasted conditions using conventional CO2 laser cutting. A mechanism to explain why the presence of residual elements results in improved cut quality is proposed. Further work required to develop a better understanding of laser cutting has been highlighted and recent process developments that could significantly impact this technology have been outlined.