Technological study of oxygen aided laser cutting silicon steel

Abstract

It is easy to produce molten dross by using traditional laser cutting technology in laser cutting silicon steel sheet. The main reason is that oxidizing reaction will take place inevitably by using oxygen as aided gas, so high pressure and high purity N₂ or inert gases is used as aided cutting gas in laser cutting process. Although the cut quality is improved, the cutting efficiency is dropped because of the lack of energy resulting from an exothermic oxidation reaction. A fire new laser cutting technology by using an additional nozzle put under the workpiece that will form lateral gas flow to control the direction of the flowing dross gas is raised. In this technology oxygen is still used as aided gas, the laser power is reduced and the cut is fine. The experiments prove that by controlling the technical parameter reasonably, glossy and dross-free cutting kerfs are obtained. The gas flow acting under the workpiece is simulated by Finite Element Method (FEM). The varieties of pneumatic fields when the additional nozzle is in different degree and flow velocity are analyzed, which provides academic basis for controlling the flowing direction of the dross gas more reasonably. This laser cutting technology is practical and feasible.