Air plasma cutting machine is an equipment for cutting medium and thin metal plates.
It has the advantages of flexible and convenient operation, smooth workpiece incision, narrow cutting seam, small thermal deformation, easy slag removal and high cutting efficiency.
However, the cutting torch nozzle is easy to be damaged, which affects the cutting efficiency and cutting quality, and increases the cutting cost.
In order to reduce the cutting cost and prolong the service life of plasma cutting electromechanical electrode nozzle, pay attention to the following points:
1. Ensure the correct air pressure and flow of plasma
The correct pressure and flow of plasma is very important for the service life of consumer parts.
If the air pressure is too high, the service life of the electrode will be greatly reduced;
If the air pressure is too low, the service life of the nozzle will be affected.
2. Adopt reasonable cutting height
According to the requirements of the operation manual, adopt a reasonable cutting height, which is the distance between the cutting nozzle and the workpiece surface.
When perforation, try to use a value slightly higher than the perforation height in the parameter table.
3. The perforation thickness shall be within the allowable range of the machine system
The cutter cannot punch on the steel plate exceeding the working thickness. The usual perforation thickness is 1 / 2 of the normal cutting thickness (below 100A).
For example, the 100A system is determined to cut 1 inch (about 25mm) of carbon steel, and the perforation thickness of the system should be 0.5 inch (about 12.5mm).
4. Do not overload the nozzle
Overloading the nozzle (i.e. exceeding the working current of the nozzle) will quickly damage the nozzle.
The current intensity should be 95% of the working current of the nozzle.
For example, the current intensity of 100A nozzle should be set to 95A.
5. Keep the plasma gas dry and clean
The plasma system needs dry and clean plasma gas to work normally.
Dirty gas is usually the problem of the gas compression system, which will shorten the service life of consumer parts and cause abnormal damage.
The method to test the gas quality is to set the cutting torch in the test state and put a mirror under it to consume the gas in the cutting torch.
If water vapor and fog appear on the mirror, it is necessary to find out the cause and correct it.
6. Cutting shall start from the edge
As far as possible, cut from the edge rather than through the hole.
Using the edge as the starting point will prolong the service life of consumables.
The correct method is to align the nozzle directly with the edge of the workpiece and then start the plasma arc.
7. Avoid plasma arc stretching and expansion
If the plasma arc can only contact the workpiece surface by stretching and expanding, this stretching and expansion will occur at the beginning and end of plasma arc cutting, which will cause abnormal damage to the nozzle.
This problem can be avoided if the correct edge starting point technique is adopted and the appropriate “arc breaking” signal time is selected.
8. Reduce unnecessary arcing (or arc guiding) time
The consumption of nozzle and electrode is very fast during arcing.
Before starting, the cutting torch should be placed within the walking distance of cutting metal.
9. Apply splash-proof chemical coating on the protective shell
The splash-proof chemical coating helps to reduce the accumulation of slag on the protective shell.
However, the protective shell must be removed from the cutting torch before anti-splash coating can be applied.
10. Remove the slag on the protective shell
Always remove the slag on the cutting torch protective shell, otherwise this slag will cause destructive heavy plasma arc.
11. Remove the gas after replacing the consumable parts
After replacement of consumable parts or long-term shutdown, the gas shall be removed (2-3 minutes is appropriate) to ensure that the water and mist are discharged from the cutting torch.
12. Try to keep the cutting torch and consumables clean
Any dirt on the cutting torch and consumable parts will greatly affect the function of the plasma system.
When replacing consumable parts, put them on a clean flannelette, often check the connecting rib of the cutting torch, and clean the electrode contact surface and nozzle with hydrogen peroxide detergent.
13. Remove oxides from air or oxygen nozzles
When air or oxygen plasma is selected, oxide will be deposited in the nozzle, which will affect the air flow and reduce the service life of consumer parts.
Wipe the inside of the nozzle with a clean lint cloth to eliminate oxides.
14. Inject softened water into the cutting torch
Hard water will cause metal impurities to precipitate on the nozzle ring, which will affect the air flow, reduce the quality of the cutting torch and shorten the service life of consumables.
15. Check the airflow and coolant flow every day
One of the most common causes of cutting torch damage is the lack of cooling flow.
It is necessary to often check the airflow and air pressure (such as air cooling) or coolant (such as water cooling) to the cutting torch.
If it is found that the airflow is insufficient or leaked, it shall be shut down immediately to eliminate the fault.