Laser Cutting Steel with Nitrogen

Laser cutting steel with Nitrogen, as the assist gas, is becoming more commonplace for parts that require painting after cutting. GF Laser are able to cut steel using Nitrogen or Oxygen depending on customer requirements.

Firstly, what is an assist gas?

The assist gas helps the laser cutting process by forcing the molten metal out of the cut made by the laser beam. Also, when cutting mild steel using Oxygen as the assist gas it also helps the laser in cutting the material.

Why laser cutting steel with Nitrogen?

If you are cutting stainless steel or Aluminium this is usually only cut with Nitrogen or compressed air (Compressed air is typically used to laser cut material up to 2mm thick). However, there are two choices when cutting mild steel: Nitrogen or Oxygen can be used as the assist gas. Cutting mild steel with Oxygen leaves an oxidised edge which for many applications does not matter. However, the oxidised edge sometimes causes a problem with paint adhesion as the paint literally slips away from the metal surface.

Cutting mild steel with Nitrogen on the other hand leaves a much cleaner edge and does not effect paint adhesion in any way.

Why not cut with Nitrogen all the time then?

Good question, firstly Nitrogen is more expensive to buy than Oxygen and it requires a higher pressure when laser cutting making the whole process more expensive. Secondly, because Oxygen also aids the laser in cutting material it is usually quicker than Nitrogen.

Are there any other options?

Yes, many companies opt for laser cutting with Oxygen but then send the parts to deburring companies such as Supersheen. These companies remove the oxidised edge using a tumbling action, this process is often cheaper than laser cutting steel with Nitrogen.

For further details on how gf laser can help you in laser cutting steel with Nitrogen please call on 0121 557 2294 or email