There are many types of cutting machines, and the functions and features of different types of cutting machines are different. CNC flame cutting machine is one of them. Many users report that they do not know how to debug the flame when using a CNC flame cutter. In fact, we only need to understand the specific characteristics of the normal flame of the CNC flame cutting machine.

The reduction zone is located outside of the flame core and is distinct from the flame core by its darkness. The reduction zone consists of carbon monoxide and hydrogen which are not completely combusted by acetylene and the temperature in the reduction zone can reach about 3000 °C. The external flame is the complete combustion zone and is located outside the reduction zone. It consists of carbon dioxide and water vapor, nitrogen, and its temperature varies between 1200 and 2500 °C. Recommended reading: What is the workflow of CNC plasma cutting machine?

An oxidizing flame is produced in the case of excess oxygen. The flame core is conical, the length is obviously shortened, the outline is not clear, and the brightness is dim; similarly, the reduction zone and the external flame are shortened, and the flame is purple-blue. The sound is accompanied by sound, which is related to the pressure of oxygen. The temperature of the oxidizing flame is higher than the temperature of the ordinary flame. If an oxidized flame is used for cutting, the quality of the cut will be significantly reduced.

A reducing flame is produced in the case of excess acetylene. The flame core has no obvious outline and the flame core has a green edge at the end. According to the green edge, there is an excess of acetylene; the reduction zone is extremely bright, almost the flame core is mixed; the outer flame is yellow. When there is too much acetylene, it will start to smoke, because the burning of acetylene in the flame lacks the necessary oxygen.

The energy of the preheated flame is closely related to the cutting speed and the cutting quality. As the thickness of the workpiece to be cut increases, the cutting speed increases, and the energy of the flame should also increase, but should not be too strong, especially when the thick plate is cut, the heat of reaction generated by the metal burning increases, and the cutting is strengthened. At this time, the preheating flame of the leading edge whose preheating ability is excessive will cause the upper edge of the slit to melt and collapse. Too weak a preheated flame will result in the steel plate not getting enough energy, which will reduce the cutting speed and even interrupt the cutting process. Therefore, the relationship between the strength of the preheating flame and the cutting speed is mutually limited.

Usually, the CNC flame cutting machine uses a neutral flame to cut steel plates below 200mm for better cutting quality. When cutting a large-thickness steel plate, the reducing flame should be preheated and cut, because the flame of the reducing flame is relatively long, and the length of the flame should be at least 1.2 times the thickness of the plate.