Laser texturing cold roll technology is a new technology for producing high-quality cold-rolled sheet steel developed in the world in the 1980s. Because laser texturing technology has greater advantages than other texturing methods in terms of processing methods, improving molding performance, brightness after coating, and comprehensive production costs, laser texturing technology has been used by iron and steel enterprises as soon as it came out. The department attaches great importance to the fact that high-quality cold-rolled sheets and strips not only require excellent materials, but also have strict requirements on the surface quality of the sheet (such as surface roughness and morphology) to ensure the excellent formability and surface coating performance of the sheet. Laser-textured car panels are called “mirror steel plates” in foreign countries because of their high glossiness of reflected images after painting. Therefore, laser-textured cold-rolled sheet (strip) is an important raw material for the production needs of automobiles, home appliances, electronics and light industries.
The basic principle of laser texturing technology:
It is characterized by using a specially modulated pulsed laser beam with high energy density (104~106W/cm2) and high repetition frequency (thousands to tens of thousands per second) to be incident on the surface of the roll for preheating and strengthening after focusing. A tiny molten pool is formed on the surface of the roll. At the same time, the auxiliary gas with set pressure, flow rate and direction is applied to the tiny molten pool by the side blowing device, so that the molten material in the molten pool can be deposited as far as possible to the edge of the molten pool to form a circular arc boss according to the specified requirements. These preheating zones, micro-pits, and bosses are rapidly cooled under the action of self-heating of the roll to form a hardness-enhancing zone. Then, in the process of thin plate rolling or leveling, the bosses on the surface of the rolls form a number of deformed and hardened particles (micro-pits) on the plate surface to form a laser textured plate. This new type of surface structure does not reduce the surface toughness of the original material, and needle rolling is performed on the surface by countless tiny and uniformly distributed strengthening points, so as to achieve a surface structure that combines rigidity and flexibility on the surface of the roll and plate. The advantages of this surface structure are mainly manifested in the following aspects:
1) Laser texturing forms evenly distributed arc-shaped bosses on the surface of the roll, and its hardness and strength are significantly higher than other texturing methods. And can effectively avoid the residual stress concentration of the roll, the reduction of toughness and other phenomena, and prolong the service life of the roll.
2) During the rolling process, improve the friction between the roll and the plate (increase the friction force) and the contact conditions to facilitate the smooth progress of the rolling process (the rolling mill reduction and rolling speed can be increased), reduce scratches and adhesions, Improve the shape of the board and improve the quality of the board surface.
3) During the plate forming process, the micro-pits on the plate surface have oil storage and cooling functions to improve the friction and contact conditions between the plate and the abrasive tool (reduce friction and increase lubrication), so as to facilitate the flow of materials and make the forming process easier. At the same time, the micro-pits on the plate surface can accommodate the metal chips generated during the forming process, reducing the scratches on the forming surface and improving the quality of the workpiece. It can enhance the adhesion of the board to the coating and improve the brightness of the paint on the surface of the formed parts, increasing the added value of the product.
