In the actual use and operation of CNC plasma cutting machine, due to factors such as the optional plasma power brand, plasma power power, plasma power cutting power, thickness of consumables such as cutting nozzle electrodes, and thickness of metal plates, the various process parameters of plasma arc cutting directly affect the stability of the cutting process, cutting quality and effect. We summarize the main cutting specifications as follows:

1. No-load voltage and arc column voltage

The power supply of the CNC plasma cutting machine must have a high enough no-load voltage to easily start the arc and make the plasma arc burn stably. The no-load voltage is generally 120-600V, and the arc column voltage is generally half of the no-load voltage. Increasing the arc column voltage can significantly increase the power of the plasma arc, thereby increasing the cutting speed and cutting a thicker metal plate. The arc column voltage requirements are often not met by adjusting the gas flow rate, increasing the electrode retraction, etc., but the arc column voltage cannot exceed 65% of the no-load voltage, otherwise the plasma arc will be unstable.

2. Cutting current

Increasing the cutting current of a CNC plasma cutting machine can also increase the power of the plasma arc, but it is limited by the maximum allowable current. Otherwise, the plasma arc column will become thicker, the slit width will increase, and the electrode life will also decrease.

3. Gas flow

Increasing the gas flow can not only increase the arc column voltage, but also enhance the compression effect on the arc column, making the plasma arc energy more concentrated and the jet force stronger, so the cutting speed and quality can be improved. However, excessive gas flow will cause the arc column to shorten, increase heat loss, and weaken the cutting ability until the cutting process cannot be carried out normally.

4. Electrode shrinkage

The so-called shrinkage refers to the distance from the electrode to the end face of the cutting nozzle. The appropriate distance can make the arc well compressed in the cutting nozzle, obtain a plasma arc with concentrated energy and high temperature, and perform effective cutting. If the distance is too large or too small, it will seriously burn the electrode and the cutting nozzle, reducing the cutting ability. The shrinkage is generally 8-11mm.

5. Nozzle height

The cutting nozzle height of a CNC plasma cutting machine refers to the distance from the end of the cutting nozzle to the surface of the workpiece being cut, which is generally 4 to 10 mm, the same as the electrode retraction. The distance must be appropriate to give full play to the cutting efficiency of the plasma arc, otherwise it will reduce the cutting efficiency and cutting quality or burn the cutting nozzle.

6. Cutting speed

The above factors directly affect the compression effect of the plasma arc of the CNC plasma cutting machine, that is, the temperature and energy density of the plasma arc, and the high temperature and high energy of the plasma arc determine the cutting speed, so the above factors are all related to the cutting speed. Under the premise of ensuring the cutting quality, the cutting speed should be increased as much as possible. This can not only improve productivity, but also reduce the deformation of the cut part and the heat affected zone of the slit area. If the cutting speed is not appropriate, the effect will be counterproductive, the sticky slag will increase, and the cutting quality will decrease.