Plasma cutting gas

CNC plasma cutting machine, usually have higher no-load voltage and working voltage, in the use of gases such as high ionization energy (ie) air or nitrogen, hydrogen, stable plasma arc required voltage will be higher. When the current, voltage of certain enthalpy of arc to improve is improving and cutting capability is improved. If the enthalpy increases, the diameter of reducing jet velocity, and increase the gas can often gain faster cutting speed and better cutting quality.

1. Oxygen can improve the speed of cutting low carbon steel materials. Use oxygen cutting, cutting mode and flame cutting very imagine, high-temperature high-energy of plasma arc cutting speed faster, but makes use of high temperature oxidation to cooperate with the electrodes, meanwhile to the electrodes arcs, in order to prolong the impact protection of electrode life.

Plasma cutting process

2. Hydrogen is often used as an auxiliary gas and other gas mixture with action, like the name of the H35 (hydrogen gas is 35%, the volume fraction of the argon plasma arc cutting ability) is one of the strongest gases, which mainly benefited from the hydrogen. Because the hydrogen can significantly raise arc voltage, make hydrogen plasma jet has high enthalpy, when blended with argon plasma jet, the cutting ability is greatly increased. General on thickness 70mm above the metal materials, common argon and hydrogen as cutting gas. If use water jet of argon + hydrogen plasma arc further compression, still can obtain higher cutting efficiency.

3. Air contains volume fraction about 78% of nitrogen, so use by the formation of the air cutting with nitrogen and hang slag during cutting very imagination; Air also contained volume fraction about twenty percent of oxygen, because the existence of oxygen with air, the cutting speed of low carbon steel material is also high; Meanwhile the air is the most economic work gas. But when used alone air, there will be cutting hang slag and incision oxidation, increase nitrogen, and electrode and nozzle life lower can also affect work efficiency and cut costs. Because of plasma arc cutting generally use constant-current or steep drop the power supply, the characteristics, current highly increase nozzle changed little, but will make arc length increase and lead to increased arc voltage, thus make arc power increased; But at the same time also can make exposed to the environment, the arc length growth increased the energy loss of arc beam.



In two factors under the condition of the comprehensive function, the former action often offset by completely by the latter, it will make effective cutting energy decreases, and cause cutting capacity reduction. Usually the performance was cutting jet blew force is abate, incision of the lower residual slag increased, the upper edge over melting and appear round, etc. In addition, the plasma jet from the ideology consideration, jet in diameter is leaving muzzle expands outward, nozzle highly increase inevitably lead to the incision width increasing. So, choose as far as possible to improve small nozzle height cutting speed and cutting quality are beneficial, but, nozzle height is too low may cause the double arc phenomenon. Adopt ceramic nozzles outside can be set to zero, nozzle height vent end direct contact with that is cut surface, can obtain good effect.

CNC Plasma Cutting Machine

4. Nitrogen is a kind of common work in a higher gas, power supply voltage conditions, nitrogen plasma arc has better stability and argon gas higher jet energy than, even if it is cutting the liquid metal viscosity materials such as stainless steel and nickel-based alloy, incision of inferior hang slag quantity are few. Nitrogen can be used alone, also can use with other gas mixture, such as automation cutting often use nitrogen or air as gas, this two kinds of gas has become the standard gas high-speed cutting carbon steels. Sometimes nitrogen are being used oxygen plasma arc cutting of arcs gas.

5. Argon in high temperature and almost not with any metal happening reaction, argon CNC plasma cutting machine, very stable. And by use of the nozzle with electrodes have higher service life. But the argon plasma arc voltage, low enthalpy is not high, cutting ability is limited, and air compared the thickness of the cutting cutting about will reduce 25%. In addition, argon protection environment, the surface tension of molten metal larger, than in nitrogen environment around 30% higher, so there will be more hang slag problem. Even use argon and other gas mixture of cutting will also have viscous slag tendency. Therefore,now rarely used alone on pure argon plasma cutting.