Melting cutting typically employs inert gases, where the material is ignited under the照射 of a laser beam, undergoing a vigorous chemical reaction with oxygen to produce another heat source, known asOxidation Melting CuttingNo Chinese content provided for translation.:
(1)Under the照射 of the laser beam, the material surface quickly reaches the ignition temperature, subsequently undergoing a vigorous combustion reaction with oxygen, releasing a large amount of heat. Under the action of this heat, steam-filled pores form within the material, surrounded by molten metal walls.
(2)The transfer of burning materials to slag controls the combustion rate of oxygen and metal. Additionally, the rate at which oxygen diffuses through the slag to the ignition front significantly affects the combustion speed. The higher the oxygen flow rate,
The speed of combustion chemical reactions and slag removal also increases. Of course, the oxygen flow rate is not the higher, the better, as excessively fast flow can lead to rapid cooling of the reaction products at the cutting seam exit, which are metal oxides, and this is detrimental to the quality of the cut.
(3)Clearly, the oxidation melting cutting process involves two heat sources: the energy from laser irradiation and the heat energy generated by the chemical reaction between oxygen and metal. It is estimated that during steel cutting, the heat released by the oxidation reaction accounts for a percentage of the total energy required for cutting.60Clearly, using oxygen as an assist gas results in higher cutting speeds compared to inert gases.
(4)In the oxidation melting cutting process with two heat sources, if the combustion speed of oxygen exceeds the speed of the laser beam, the cut seam appears wide and rough. Conversely, if the speed of the laser beam is faster than the combustion speed of oxygen, the resulting cut seam will be narrow and smooth.
