How to calculate nitrogen demand for laser cutting machines?

The Role of Nitrogen in Laser Cutting Quality

Preventing oxidation: Why nitrogen is essential during laser cutting

In laser cutting operations, nitrogen serves as a protective shield against oxidation by pushing out oxygen from the cutting area. Metals such as stainless steel and aluminum tend to react badly when heated up, causing those unsightly rough edges and discoloration problems. The good news is that nitrogen doesn't react with these materials because it's chemically inert, so we get clean cuts free from oxides. Take stainless steel cutting for instance the difference between using nitrogen versus regular oxygen assisted techniques can actually make surface roughness drop around 25%. This matters a lot in industries where parts need to be ready for welding right away or when appearance counts for things like consumer products and architectural components.

How inert gas ensures clean, high-quality cuts in metal fabrication

Nitrogen does more than just prevent oxidation during cutting operations. It actually helps cool down the area where the cut happens, which reduces warping caused by heat and keeps the laser beam focused properly. The end result? Cleaner cuts with less leftover material sticking around, especially noticeable when working with sheets thinner than about 10 millimeters thick. Another benefit worth mentioning is how nitrogen clears out debris from the path of the laser beam itself. This cleaning action ensures the beam stays strong and steady throughout the process. For shops dealing with tight specifications, this matters a lot because it allows them to maintain those super strict tolerance requirements of plus or minus 0.1 mm that many precision parts demand these days.

Key Parameters Affecting Nitrogen Flow Rate and Pressure

Nozzle Diameter and Gas Flow Rate: Their Effect on Cutting Efficiency

Raysoar summarizes a correspondence table for the nozzle diameter and flow rate based on generating 99.99% nitrogen by the BCP series products :

For cutting the mild steel or aluminum alloy, Raysoar provides the reference as follows:

Balancing Flow Rate and Pressure for Consistent Laser Cutting Performance

A 6 kW fiber laser cutting 5 mm stainless steel illustrates the balance:

• Underpressurized (10 bar): 0.3 mm edge oxidation, 12% slower feed rate
• Optimized (14 bar): Mirror-finish edges, 8.5 m/min cutting speed
• Overpressurized (18 bar): 15% gas waste, nozzle wear triples

Real-time pressure regulators maintain ±0.7 bar variance, improving material yield by 9% in high-mix production environments.

Determining Nitrogen Purity Requirements for Different Applications

The different purity of nitrogen is needed by different materials. For a stainless steel and the high precision machinery, 99.99% and above purity is necessary for ensuring the bright and clean cut. However for the mild steel and aluminum alloy  lower purity ranging from 90%-98% purity is recommended for a better burr free cutting compared with the air cutting or oxygen cutting and liquid nitrogen. By consuming less nitrogen and generating the assist gas on site, the production costs is reduced by up to 70%. Raysoar’s FCP series products demonstrate the advantages of generating the mix-gas for the carbon steel/ mild steel/alluminum alloy cutting applications.

Sizing On-Site Nitrogen Generation Systems for Laser Cutting Operations

Matching Nitrogen Generator Output to Laser Machine Demand

Effective system sizing requires evaluating peak flow rate (typically 25–50 m³/hr per laser), required purity (≥99.995% for sensitive alloys), and operational patterns. Modern on-site systems reduce gas costs by 50%-90% compared to liquid nitrogen when sized using actual machine consumption data and depending on the electricity costs and liquid nitrogen or cylinder gas costs in different areas and different countries.

Accounting for Number of Laser Machines and Runtime Patterns

Raysoar’s on site nitrogen generating systems provide multi machine operation function. By calculating the nitrogen consumption flow, the corresponding model is applied, which means the raysoar’s on site nitrogen generators can provide the assist gas for 2-4 machines at the same time on site.

Case Study: Nitrogen Demand Calculation for a 2-Machine Metal Fabrication Shop

A small-sized facility replaced the cylinder gas by running a BCP40 for cutting mostly the stainless steel:

• Real-time monitoring the flow of nitrogen needed for 2 machines:3kw tube cutting and 4kw flat cutting;
• S2.0 nozzle are applicable for both machines at the same time because the tube cutting machine consumes less nitrogen compared with the flat cutting.
• For cutting other materials such as the mild steel with 3mm thickness, lower purity is needed which means the sufficient nitrogen flow is ensured by switching to the carbon steel mode.

Frequently Asked Questions (FAQ)

Why is nitrogen used in laser cutting?

Nitrogen is used in laser cutting to prevent oxidation and discoloration, providing clean and high-quality cuts for metals like stainless steel. 

How does nitrogen affect the quality of laser cutting?

Nitrogen cools down the cut area, reduces warping, and ensures the laser beam remains focused, leading to cleaner cuts with precise tolerance.

What factors determine nitrogen consumption in laser cutting?

The type and thickness of the material, nozzle diameter, and nozzle geometry are key factors influencing nitrogen consumption.

What is the required nitrogen purity for laser cutting?

Typically, a nitrogen purity of 99.99% or higher is needed to ensure high-quality, oxidation-free cuts for stainless steel. However lower purity from 90-98% is also applicable for those materials such as mild steel and aluminum alloy. In fact the purity required for laser cutting depends on customers cutting requirement, balancing the cost and efficiency.