Views: 30 Author: Site Editor Publish Time: 10-11-2021 Origin: Site
With the continuous development of laser technology, laser cutting machines can already be used to cut medium and thick plates. And the effect of cutting medium and thick plates is still good, but there are still some technical difficulties and problems in laser cutting of medium and thick plates, such as cutting section and perforation. Below, Leapion Laser will share with you how to solve the common problems of laser cutting medium and thick plates.
There are three general common problems of laser cutting machine cutting medium and thick plates: perforation, cutting section and instability of the whole plate processing. Let's find out in detail below:
Perforation time accounts for a large proportion in the processing of thick plates, and various laser manufacturers have developed rapid perforation technologies, and the more representative one is high-energy perforation (blasting).
The advantage of this method is that it is fast (1 second, taking t16mm as an example—the same below). The defect is that it not only affects the processing of small shapes, but the huge energy injected during perforation increases the temperature of the sheet and affects the subsequent overall cutting process. . However, if a low-power pulse is used for perforation, the time is very long (12 seconds), which will lead to a decrease in cutting efficiency and an increase in unit cost.
When processing medium and heavy plates, cutting sections are often encountered. Such cutting not only has the quality of the finished product questioned, but also will be accompanied by over-burning and serious sticky slag, so that it does not reflect the value of the expensive laser processing machine from other cutting methods.
In the whole plate processing of steel, there is often a phenomenon of poor processing in local areas. This phenomenon is sometimes very random, even when the processing machine is in good condition.
The above three problems are very common in the daily processing of medium and heavy plates, and there have been better solutions to them, as follows:
The HPP scheme refers to the use of high-peak pulse lasers with a small duty cycle, supplemented by non-fuel sprayed on the surface of the material to remove the attachments on the edge of the opening, and to control the reasonable frequency of the pulse while cooling and perforating.
Its characteristic is that although the relative blasting time is slightly longer (3 seconds), the hole diameter is small (about φ4mm), there is no adhesion on the edge of the hole, and the heat input is lower, which is convenient for the subsequent normal cutting and processing, compared with ordinary piercing The efficiency is increased by 4 times.
For carbon steel, an important factor to improve the cutting section is to control the heat input to the sheet and to ensure the full combustion of the laser-irradiated part.
For stainless steel, the important factors to improve the cutting section are the improvement of the beam (improving the depth of focus) and the effective use of auxiliary gas. The bright cutting technology is the result of improving the vibrator and nozzle.
At present, in order to increase the operating speed of the processing machine, the laser machine mostly adopts the structure commonly known as the flying light path, that is, the material tray does not move while the processing head moves in the entire processing area. In order to compensate for the change in the relative position of the processing head and the light source, various manufacturers try their best to ensure the consistency of the light spot within the processing range, and the use of a variable curvature refractor is a common choice.
Although this method has a simple structure, it will change the depth of focus, making it difficult to cut the medium and thick plates where the depth of focus is extremely sensitive (it is necessary to keep the spot and the depth of focus unchanged).
1) The use of equal-length optical path (the light propagation path between the light source and the processing head is the same length within the processing range) can avoid changes in the focal depth, so that the spot and focal depth are consistent.
2) In addition, the emphasis on heat input makes the heat accumulated in the plate controlled, which can better solve the stability problem.
So if you want to know other information and professional questions about the laser cutting machine, welcome to consult Leapion Laser.
