氧助激光切割是一种高效的中厚碳钢板激光切割方法, 其加工质量主要取决于切口条纹形态、切缝宽度和切缝倾角等因素。选用不同的切割速度、氧气压力和焦点位置, 对 10 mm厚度的低碳钢板进行氧助激光切割实验, 分析上述关键切割参数对切口条纹等质量因素的影响规律。实验发现, 气压增大和焦点降低会加强金属基质的燃烧, 加大了条纹波长和深度; 而切割速度的提升则在增大条纹波长的同时减小了条纹深度, 并存在一个临界速度, 当切割速度大于此速度时条纹现象将消失。此外, 切割速度的下降、氧气压力增加或焦点位置下降, 切缝宽度会增大, 而焦点位置变化对切缝宽度的影响尤为明显。

Oxygen-assisted laser cutting is an effective way of cutting thick mild steel, and the cutting quality is characterized bystriation, kerf width and kerf taper angle. A cutting experiment of 10mm thick mild steel sheet is designed in this article, where keyparameters such as cutting speed, oxygen pressure and focus position are varied in order to investigate their influence on striation andkerf width. The study finds that increasing oxygen pressure and lowering focus position will enhance the combustion of metalsubstance, thus striation wavelength and depth are increased; meanwhile, increase in cutting speed will reduce striation depth whenincreasing striation wavelength, also there exists a critical speed upon which the striation phenomenon will be eliminatied. Furthermore, slowing cutting speed, increasing oxygen pressure or lowering focus position will cause kerf width to enlarge, and focusposition has the most significant influence.