The Selection of Laser Cutting Gas and Pressure for Fiber Laser Cutter
At the time of laser cutting, select different cutting gases according to the metal for cutting. The selection of cutting gas and its pressure has a great effect on laser cutting quality.
The functions of cutting gas mainly include: combustion-supporting, heat dissipation, blowing off the molten stains generated during cutting, preventing the residue popping upwards to entering the nozzle and protecting focusing lens.
a: Influence of cutting gas and pressure on cutting quality of fiber laser cutter
1) Cutting gas helps heat dissipating, burning and blowing off molten stains, thus obtaining cutting fracture surface with better quality.
2) In case of insufficient pressure of cutting gas, will influence the cutting quality such as : Molten stains arise during the working, can’t meet the needs of cutting speed and also affect the working efficiency of fiber laser cutter
3) When the pressure of cutting gas is too high, will affect the cutting quality ;
The cutting plane is coarse and the joint-cutting is relatively wide; Meanwhile, partial melting occurs to cross section of cutting and no good cross section of cutting is formed.
b: Influence of cutting gas pressure on perforation of cnc fiber laser cutter
1) When the gas pressure is too low, the fiber laser cutter cannot easily cut through the board, thus punching time shall increase, and low efficiency
2) When gas pressure is too high, the breakthrough point can be melt down with popping occurred. Thus causing lager melting point which influences the cutting quality.
3) During laser punching, generally higher gas pressure for thin plate punching and lower gas pressure for thick plate punching.
4) In the case of cutting ordinary carbon steel with fiber laser cutter machine, the thicker the material is, the lower the cutting gas pressure will be. At the time of cutting stainless steel, the pressure of cutting gas is always under the state of high pressure although cutting gas pressure fails to change along with the material thickness.
In short, the choice of cutting gas and pressure shall be adjusted according to the actual situation when cutting. Should chose different cutting parameters in a specific situation. Shall reserve two gas pipelines for our equipment before leaving the factory, of which the oxygen and air share the same pipeline and nitrogen uses one high-pressure pipe. Two gas pipelines shall be connected with pressure relief valve as shown in the following figure:
Explanation on pressure relief valve: The table on the left shows the current pressure and the table on the right shows remaining gas volume.
“Warning”-Supply pressure of nitrogen can not exceed 20kg;
Supply pressure of nitrogen can not exceed 10Kg, or it’s easy to cause burst of air pipe.