What is plasma cutting

2025-05-15

Plasma Cutting is a processing technology that uses high-temperature plasma arc to melt and cut metal materials. Its core is to achieve efficient cutting by generating high-energy plasma through ionized gas.

1. Basic principles

Plasma generation
When gases such as compressed air, nitrogen or argon pass through the nozzle of the Cutting Torch, a high-voltage arc is applied between the electrode and the workpiece, causing the gas to ionize and form plasma (ionizing high-temperature conductive gas, with a temperature reaching 10,000-30,000℃).
Cutting process:
High-energy plasma arcs focus on impacting the local area of the workpiece, rapidly melting the metal. At the same time, high-speed gas flow blows away the molten material, forming a cut.

2. System Composition

Power supply: Provides DC high voltage (usually 200-400V) to maintain arc stability.
Cutting torch: Core component, including electrodes (commonly hafnium or tungsten), nozzles (made of copper, to confine the arc), and gas channels.
Gas supply
- Working gases (such as air, O₂, N₂) are used to generate plasma;
- Auxiliary gases (such as CO₂) protect the cutting surface.
- Cooling system: Water cooling or air cooling to prevent the cutting torch from overheating.

3. Technical Features

Advantages:

1. It can cut all conductive metals (including stainless steel, aluminium, copper, etc.);
2. The speed is faster than that of oxyacetylene cutting (for example, 20mm carbon steel can reach 2m/min).
3. High precision (incision width approximately 1-3mm);
4. No preheating required, suitable for automation.

Limitations:

1. The equipment cost is relatively high.
2. When cutting thick plates (>50mm), the bevel Angle is relatively obvious.
3. Protection against noise and ultraviolet radiation is required.

4. Process type

Ordinary plasma cutting: Single gas, suitable for medium and thin plates.
Fine plasma cutting
The arc is compressed by technologies such as eddy current rings, achieving higher precision (cut width ≤1mm), and is suitable for precision processing.
Water recompression plasma cutting
The water flow wraps around the plasma arc, reducing smoke and dust and improving the quality of the incision.

5. Application fields