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Views:0 Author:hu Publish Time: 2021-09-04 Origin:dapeng
Laser cutting and blanking requires two steps to achieve-perforation and cutting. Only by ensuring a good and stable perforation effect can cutting be achieved.
When thick plates are perforated, they are prone to blast holes, which can cause problems such as unstable cutting, damage to lenses and nozzles. Therefore, in order to obtain a good sample effect while stable processing, excellent perforation is the first step.
Pulse perforation method
Fiber laser cutting generally adopts high peak power pulse laser method to melt a small amount of material. Carbon steel cutting usually uses oxygen as an auxiliary gas. Each pulse laser will produce smaller particle jets and gradually deepen, so that the diameter of the perforation is small and the jets are sprayed. There is less slag, and the cutting start is more stable. The pulse perforation method must have a better gas path control system to achieve fine control of gas type and gas pressure.
Pulse perforation laser parameters
Pulse period: T=1/frequency, pulse width: t=T*duty ratio
For example, Figure 1: Pulse frequency 500HZ, duty cycle 50%
Obtained: pulse period T=1/500=2ms, pulse width t=2*50%=1ms
Cause of blasthole
During the piercing process, blastholes are often encountered, as shown in the figure below, when the 30mm carbon steel is pierced, the blastholes may be caused by the following reasons:
1. The pulse duty is relatively large;
2. The perforation air pressure is set too high;
3. The perforation pulse frequency is too high;
4. Between multi-level perforation, blowing without stopping light or blowing time is too short;
Normal effect picture of perforation
Effect picture of blasthole
Blast hole solution
1. The pulse duty ratio is relatively large:
2. The perforation air pressure is set too high:
3. The perforation pulse frequency is too high:
Guidance of perforation method:
1. The peak power is as high as possible to improve the efficiency of perforation;
2. Ensure that the laser spot will not hit the nozzle, and the perforation focus will be appropriately reduced;
3. The oxygen perforation air pressure is equivalent to the cutting air pressure;
4. Add stop light blowing between multi-level perforation, which is not easy to blast.