Laser assisted oxygen cutting of thick mild steel with off-axis beam delivery of 400 W fiber-coupled diode lasers

Laser assisted oxygen (LASOX) cutting is a method for cutting thick steel sections by utilizing the energy released in the exothermic oxidation of iron to its full capacity, continuously preheating the area of the oxygen jet impingement to the ignition temperature (~1000 °C) [1] . The process is very similar to the well-known flame (oxyfuel) cutting with preheating flames substituted by a laser heat source. The required laser power is relatively low (~1 kW for optimal edges quality) and cutting of up to 50 mm thick mild steel was demonstrated using defocused beams from CO 2 , as well as Nd:YAG and Yb-fiber lasers. Using high power diode lasers to support oxygen cutting of mild steel was already considered in more early works [2] and recent developments in this type of laser sources may present an opportunity for the LASOX method. Another interesting possibility is abandoning the natural coaxial geometry of the laser beam and the gas jet and delivering the preheating laser beam off-axis to the cutting oxygen.