What are the main factors affecting the quality and effect of plasma cutting

What are the main factors affecting the quality and effect of plasma cutting

Due to the optional machine plasma power supply, the power of the plasma power supply, the cutting torch of the plasma power supply, the consumables such as the cutting nozzle electrode and the thickness of the metal plate, etc., as well as various plasma arc cutting process parameters, it directly affects the actual use and Operational CNC plasma cutting machine for cutting stability, cutting quality and effect. Mainly in the following aspects:

1. Electrode retraction. The so-called retraction refers to the distance from the electrode to the end face of the cutting nozzle. A suitable distance can make the arc well compressed in the cutting nozzle and obtain a plasma arc with concentrated energy and high temperature for effective cutting. If the distance is too large or too small, the electrode will be seriously burned, the cutting tip will be burned out and the cutting ability will be reduced. The amount of shrinkage is generally 8-11mm.

2. cutting current. Increasing the cutting current 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 decrease.

3. cutting speed. The above factors directly affect the compression effect of the plasma arc, 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 related to the cutting speed. On the premise of ensuring the cutting quality, the cutting speed of the plasma cutting machine should be improved as much as possible. This not only increases productivity, but also reduces the amount of deformation of the part being cut and the heat-affected zone in the kerf area. If the cutting speed is not suitable, the effect will be opposite, and it will increase the slag and reduce the cutting quality.

4. Gas flow. Increasing the gas flow can not only increase the arc column voltage, but also enhance the compression effect on the arc column, so that the plasma arc energy is more concentrated and the jetting force is stronger, so the cutting speed and quality can be improved. However, if the gas meteor is too large, the arc column will be shortened, the heat loss will increase, and the cutting ability will be weakened, until the cutting process of the plasma cutting machine cannot be carried out normally.

5. No-load voltage and arc column voltage. The plasma cutting power supply 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 metal sheets with larger thicknesses. The arc column voltage is often not reached by adjusting the gas flow and increasing the retraction of the electrode, but the arc column voltage cannot exceed 65% of the no-load voltage, otherwise the plasma arc will be unstable.

6. Nozzle height. The height of the cutting tip refers to the distance from the end face of the cutting tip to the surface of the workpiece being cut. The distance is generally 4~10mm. It is the same as the retraction of the electrode, and the distance must be appropriate to give full play to the cutting efficiency of the plasma arc, otherwise the cutting efficiency and cutting quality will be reduced or the cutting nozzle will be burned out.