New developments in laser-assisted oxygen cutting

It has been nearly 33 years since the first laser cut was produced at The Welding Institute, Cambridge, UK. It is quite remarkable that laser cutting as we know it today has changed very little since these first trials. The developments that have taken place relate to greater process understanding, improved laser sources, enhanced beam-handling systems and process refinements. Much effort has been placed in improving the efficiency of the process such that thicker sections can be cut with moderate laser powers. Yet, for all of these developments laser cutting has seen little movement in maximum section limits that can be cut. Commercial process providers routinely cut to maximum depths of around 12-15mm in mild steel with 2kW lasers. While it is true that the market is small for steel sections above 15mm it is apparent that some industries such as offshore, marine, construction and heavy engineering would benefit greatly from a laser process capable of cutting sections much greater than 15mm. This paper presents results obtained from a study of a new thick section laser-cutting process capable of cutting sections up to 50mm thick in the first instance, with power levels less than 2kW whilst maintaining excellent cut quality. The work presents initial results of cutting steel up to 50mm thick and examines the process using theoretical and experimental analysis.