Common problems in laser cutting of medium thick metal sheet
1. Perforation of thick carbon steel plate
The perforation time accounts for a large proportion in the thick plate processing. Various laser manufacturers have developed rapid perforation technology, which is representative of high-energy perforation (blasting). The obvious advantage of this method is that the speed is fast (1s), but the defect is that it not only affects the processing of small shape materials, but also the huge energy injected during the perforation increases the temperature of the plate, which affects the following overall cutting process 。
2. The stability of the whole plate processing
In the whole plate processing of steel, the phenomenon of bad local area processing often occurs. This phenomenon is sometimes very random, even when the processing equipment is in good condition, and in order to deal with these local fault products, it will greatly affect the progress of the whole work.
Solution to the problem of laser cutting of medium and thick plate
1. Using the peak perforation (HPP) scheme
As the name implies, the peak value pulse laser with a small duty cycle is used, assisted by the non fuel injected on the surface of the material (to remove the attachment at the edge of the opening), and then the reasonable frequency of the pulse is controlled, so as to achieve cooling and perforation at the same time. It is characterized by a relatively long time (3 seconds) for hole blasting, but the hole diameter is small (about φ 4mm), and there is no attachment at the edge of the hole and the heat input is low, which is convenient for the normal cutting and processing. Compared with the ordinary hole drilling, the efficiency of this method is several times higher.
2. Scheme to ensure processing stability
At present, in order to improve the operation speed of the processing equipment, laser cutting machine mostly adopts the structure commonly known as "flying light path", that is, the form of the machining head moving in the whole machining area without moving the material tray. In order to compensate for the change of the relative position between the machining head and the light source, and to ensure the consistency of the light spot in the machining range as much as possible, the method of variable curvature refractor is generally used for cutting. leapion