• linkedin (2)
  • sns02
  • sns03
  • sns04

What gas does the cnc gas cutting machine use?

1. What gas does the cnc gas cutting machine use?

The cnc gas cutting machine is a kind of processing equipment that uses the heat of high-temperature plasma arc to locally melt (and evaporate) the metal at the incision of the workpiece, and uses the momentum of high-speed plasma to remove the molten metal to form the incision. Oxygen cuts hard-to-cut metals. Commonly used the cnc gas cutting machine working gases are:

 gases 1

1. Air

The air contains about 78% nitrogen by volume, so the slag formation formed by air cutting is very similar to that when cutting with nitrogen; in addition, the air also contains about 21% oxygen by volume. The speed of air cutting mild steel materials is also very high; at the same time, air is also the most economical working gas, and the nozzles and electrodes used have a high service life.

2. Oxygen

The cnc gas cutting machine that use oxygen as the working gas can increase the speed of cutting mild steel materials, but when oxygen is used alone for cutting, there will be dross and kerf oxidation, and the life of electrodes and nozzles is low, which will also affect work efficiency. and cutting costs.

 gases 2

3. Argon

Argon gas hardly reacts with any metal at high temperature, the argon used by the cnc gas cutting machine is very stable, and the nozzles and electrodes used have a long service life. However, the argon plasma arc has low voltage, low enthalpy, and limited cutting ability. Compared with air cutting, the cnc gas cutting machine cutting thickness will be reduced by about 25%. In addition, in the argon protection environment, the surface tension of the molten metal is larger, which is about 30% higher than that in the nitrogen environment, so there will be more slag problems. Even the cnc gas cutting machine cutting with a mixture of argon and other gases can have slag sticking problems. As a result, pure argon alone is rarely used for plasma cutting today.

4. Hydrogen

Hydrogen is usually used as an auxiliary gas to mix with other gases used by the cnc gas cutting machine. For example, the well-known gas H35 (the volume fraction of hydrogen is 35%, and the rest is argon) is one of the gases with the strongest plasma arc cutting ability, which is mainly due to hydrogen. Since hydrogen can significantly increase the arc voltage, the hydrogen plasma jet has a high enthalpy value. When it is mixed with argon for the cnc gas cutting machine, the cutting ability of the plasma jet is greatly improved. Generally, for metal materials with a thickness of more than 70mm, argon + hydrogen is commonly used. As cutting gas, if water jet is used to further compress the argon + hydrogen plasma arc, higher cutting efficiency can also be obtained when the cnc gas cutting machine cutting.

5. Nitrogen

Nitrogen is a commonly used working gas for the cnc gas cutting machine. Under the premise of higher power supply voltage, nitrogen plasma arc has better inactivity and higher jet energy than argon, even when cutting liquid metal materials with high viscosity such as In the case of stainless steel and nickel-based alloys, the amount of slag hanging on the lower edge of the cut is also very small when the cnc gas cutting machine cutting. In the actual cutting process, it is recommended to select a suitable working gas for the cnc gas cutting machine according to your own cutting requirements and economic costs.

 gases 3

Second, the air plasma cutting machine requirements for air

Air plasma cutting machine, as the name suggests, is a plasma cutting machine that uses air as the working gas. The cnc gas cutting machine has certain requirements for the air used:

The air used by the cnc gas cutting machine is compressed air, which requires the gas to be dry and pure, and the flow and pressure to be stable, because during the normal cutting process of the cnc gas cutting machine, the pressure of the gas, the stable air flow, and the dryness and purity of the gas have a direct impact. The quality of the cnc gas cutting machine cutting and whether the arc can be started normally. Generally, it can be checked by the following methods:

1. Check whether the air pressure gauge on the cnc gas cutting machine alarms. If the cnc gas cutting machine alarms, please turn the air pressure adjustment button to increase the air pressure.

2. Check whether the air flow on the cnc gas cutting machine is normal, turn on the air release switch to deflate to see if the air pressure gauge drops, if the drop is too much, it means that the air pressure flow is not enough, then a gas storage tank should be added in front of the cnc gas cutting machine to ensure the gas traffic;

3. Check whether the gas is dry and pure, press the bottom of the oil-water separator of the the cnc gas cutting machine, and let it out. If there is a large amount of white liquid in the released gas, it means that there is a lot of oil and water in the air. This kind of air should not be used.

Post time: Jul-22-2022