With the rapid development of sheet metal processing technology, domestic processing technology is also constantly updated and iterated. In the application of sheet metal cutting, cutting equipment mainly includes shearing machine, punch, flame cutting, plasma cutting, high-pressure water cutting, laser cutting, etc.
The laser cutting machine will generate a lot of heat when processing sheet metal. Normally, the heat will spread to the interior of the sheet metal along the cutting section. In the process of small hole processing, the outer side of the hole can be fully cooled, and the small hole part inside the single hole has a small diffusion space. The heat diffusion cannot be too concentrated, which will cause over burning, slag hanging, etc.
In addition, during the thick plate cutting, the molten metal accumulated on the surface during the perforation process and the high heat accumulation required for thick plate cutting will lead to the disorder of the auxiliary gas, which will lead to the increase of heat, thus causing overburn. So how to effectively prevent overburning when laser cutting sheet metal?
1. Add cooling point or use ring cut function
When cutting plates with sharp corners, the position where overburning is easy to occur is often at the sharp corner, and overburning will cut the sharp corner round. At this time, a cooling point can be added at the sharp corner, and a pause at the sharp corner and a blow of air can effectively prevent overburning. Or adopt the ring cutting function, which can prevent the over burning caused by excessive heat due to slow speed at sharp corners.
2. Use high power laser
When cutting carbon steel, a higher power laser can be used, and the bright cutting process can effectively prevent over burning, and this cutting process can cut the finished product without burrs and bright cut surface. High power can effectively prevent over burning.
3. Cutting with nitrogen
In the sheet metal cutting with oxygen as the auxiliary gas, nitrogen can be switched for cutting. When cutting with nitrogen, the material is completely melted by laser energy, and the chemical reaction between nitrogen and sheet metal itself will not occur easily. The temperature in the melting point area is relatively low. With the cooling and protection of nitrogen, the reaction is stable and uniform, and the cutting quality is high. The section is fine and smooth, the surface roughness is low, and there is no oxide layer.
4. Increase air pressure
When laser cutting machine is used to process aluminum alloy and stainless steel, nitrogen or air is used as the auxiliary gas, and edge burning will not occur during cutting. However, due to the high temperature of the material inside the small hole, slag hanging will occur frequently inside. In this case, burr and slag can be reduced by increasing the pressure of auxiliary gas.
Characteristics of sheet metal laser cutting
Laser cutting has the advantages of high flexibility, fast cutting speed, high consumption efficiency, and short product consumption cycle, and has quickly been favored by the consumer market. Compared with traditional cutting methods, laser cutting has the following characteristics:
1. Laser cutting has high flexibility, fast cutting speed, high production efficiency and short production cycle;
2. Laser cutting without cutting force, processing without deformation;
3. No tool wear, good material adaptability and long effective life;
4. No matter simple or complex sheet metal parts, they can be cut by laser precision rapid prototyping in one time;
5. The cutting seam is narrow, the cutting quality is good, the degree of automation is high, the operation is simple, the labor intensity is low, and there is no pollution;
6. It can realize automatic cutting layout and nesting, improve the utilization rate of materials, lower production cost and good economic benefits.
