Nowadays, it is common for sheet metal companies to use laser cutting. The advantage of sheet metal laser cutting is that it is a processing method that does not touch the material, so it will not damage the surface of the sheet, and there will be no burrs on the cut surface, which is a processing method that can significantly reduce the subsequent processes. However, laser cutting will also encounter various practical problems that are difficult to overcome. Here we will focus on the cutting difficulties and solutions of laser cutting galvanized steel, which are commonly used in daily processing.
According to auxiliary gas, there are generally three laser cutting processes for galvanized steel, namely air cutting, oxygen cutting, and nitrogen cutting. Now, let's analyze the advantages and disadvantages of the three cutting processes:
1. Cutting with air
The advantage is that the processing cost is meager, and only the electricity costs of the laser itself and the air compressor need to be considered, and there is no need to generate high auxiliary gas costs. It is an economical and efficient cutting method. But the shortcomings on the cut surface are equally obvious. First of all, the air-cut section will produce bottom burrs, and the products after laser processing must undergo secondary processing such as deburring, which is not conducive to the entire production process. Secondly, the section of air cutting is easy to turn black, which affects the quality of the product. Therefore, the advantages of laser processing without subsequent processing can not be reflected, so in laser cutting galvanized steel, many companies are unwilling to choose this method.
2. Cutting with oxygen
It is the most traditional and standard cutting method. The advantage is that the gas cost is low, and in the sheet metal processing dominated by carbon steel, there is no need to frequently switch the auxiliary gas, which is convenient for factory management. But the disadvantage is that after oxygen cutting, there will be a layer of oxide scale on the surface of the cut surface. If the product with an oxide scale is directly welded, the oxide scale will naturally peel off over time. This is one of the reasons why galvanized sheet welding is easy to weld.
3. Cutting with nitrogen
When nitrogen is used for high-speed processing, the role of nitrogen is different from oxygen used for combustion, but it plays a protective role, so the cut section will not produce an oxide scale. Many companies are fancy it, so the cutting of galvanized steel sheets often use nitrogen for processing.