In laser cutting, the selection of gas and pressure directly impacts cutting speed, edge quality, and production costs. Different materials require tailored gas strategies, while pressure adjustments determine slag removal efficiency and heat-affected zone control. Today, we'll break down these key parameters to help you boost cutting efficiency and quality!
The Effect of Cutting Gas: Not Only Blowing Slag
The laser cutting gas primarily serves the following functions:
- Blowing out slag (key function).
- Auxiliary combustion (e.g. oxygen).
- Cooling zone (to prevent overheating deformation).
- Protective cut (e.g., nitrogen for oxidation prevention).
Advantages and Disadvantages of Different Gases
Oxygen
- Advantages: Strong combustion effect, can improve the cutting speed.
- Disadvantages: It oxidizes metals, causing the cut surface to turn black and yellow.
- Scenarios: Thick plate cutting, high-speed cutting, and ultra-thin plate cutting.
- Suitable materials: Stainless steel, carbon steel.
Nitrogen
- Advantages: inert gas, no oxidation reaction, the cut surface retains its original color.
- Disadvantages: Slow cutting speed and high cost.
- Suitable for products requiring high-quality cutting surfaces and exposed surfaces, such as decorative items and aerospace components.
- Suitable materials: stainless steel, electroplated steel, brass, aluminum, aluminum alloy, and other sheet metal cutting.
Air
- Advantages: Lowest cost, ideal speed is between oxygen and nitrogen.
- Disadvantages: Contains 21% oxygen, with a slightly oxidized and yellowed cut surface.
- Application scenarios: This method is typically used for relatively thin sheets where surface requirements are not stringent. Compressed air is widely utilized in industries such as sheet metal machinery, cabinets, and kitchen equipment.
- Suitable materials: aluminum, aluminum alloys, stainless copper, brass, electroplated steel plates, non-metallic materials, etc. However, when high-quality requirements are imposed on the cut products, aluminum, aluminum alloys, and stainless steel are unsuitable for air exposure, as air oxidation of the base material may occur.
Argon
- Advantages: Argon is an inert gas, used in laser cutting machine to prevent oxidation and nitriding.
- Disadvantages: High cost, whitish incision surface.
- Applicable material: titanium, titanium alloy.
Pressure Regulation: How to Balance Speed and Quality?
Pressure not only affects slag discharge, but also controls heat input and cutting width, which should be adjusted flexibly according to the material.
Increased gas pressure, which will accelerate the cutting speed and improve the cutting efficiency, but also increase the cutting heat, resulting in material deformation or combustion.
- If the pressure is too high, the cutting surface will be very deep, the roughness will be increased, and the cutting seam will be widened.
Decreased gas pressure will reduce the cutting heat and keep the surface smooth and precise, but the cutting speed and efficiency will be reduced.
- If the pressure is too low, the slag cannot be blown away effectively, and the slag will hang at the bottom.