The effect of laser processing parameters on the fume generated during cutting of mild steel

摘要

Laser cutting of steel is an important industrial process undertaken globally. The demand for high throughputs and product quality is met with the implementation of control systems. Most of the control systems available to date are based on single variables (such as power, velocity, etc.) which are not measurands of the process performance. We have found that the fume generated during cutting provides a direct measure of the process performance. Fume production involves the interaction of all laser parameters. The effects of laser operating parameters (power, velocity, etc.) on the particle size distribution of the fume shows a strong correlation with cut-quality measurands - edge roughness, kerf width, striation frequency and angle. Mean particle size was found to be a minimum at optimum process performance/product quality. A mathematical model of the steel cutting process, including the hydrodynamic instabilities in the cutting region, has been shown to provide an insight into particle formation. An example is given which demonstrates all these issues and how the process can be optimised for cutting mild steel sheet.