Nd:YAG laser reactive fusion cutting of thick mild steel by novel techniques

Reported here are the results of experiments investigating the cutting of thick (>20 mm) mild steel plate using various novel cutting techniques with a 2.5 kW, fibre coupled, Nd:YAG laser. Cutting methods used were conventional reactive fusion cutting, spinning beam cutting, wobbling beam cutting, low pressure oxygen dominated cutting (LoPOx) and high pressure oxygen dominated cutting (HiPOx). Comparison of these cutting methods shows that despite the changes to the beam delivery, the cut mechanism itself remains unchanged. The process of cutting thick steel plate with the Nd:YAG is primarily a balance between incident laser energy, assist gas conditions and most importantly the ability to remove the dross from the bottom of the cut. This paper shows and compares the results of each cut method, as well as providing insight into laser reactive fusion cutting of thick steels.