Laser texturing of cold rolls is an advanced technology developed in the 1980s for producing high-quality cold-rolled steel sheets. Due to its significant advantages in processing method, formability improvement, post-coating reflectivity, and overall production cost, laser texturing has been highly valued by steel manufacturers since its introduction. High-quality cold-rolled sheets and strips require not only excellent material properties but also strict control over surface characteristics—such as roughness and morphology—to ensure superior formability and coating performance. Known internationally as “mirror steel plates,” laser-textured automotive panels are renowned for their high-gloss painted surfaces. As a result, laser-textured cold-rolled sheets and strips serve as essential raw materials in the automotive, appliance, electronics, and light industries.
Basic Principle of Laser Texturing Technology:
This technology utilizes a specially modulated pulsed laser beam with high energy density (10⁴–10⁶ W/cm²) and high repetition frequency (thousands to tens of thousands of pulses per second). The beam is focused onto the preheated and strengthened roll surface to form tiny molten pools. Simultaneously, auxiliary gas—with controlled pressure, flow rate, and direction—is applied via a side-blowing device to redistribute the molten material toward the edges of the pools, forming arc-shaped protrusions. These preheated zones, micro-dimples, and raised structures are rapidly cooled by the roll’s self-conduction, resulting in hardened zones.
During the rolling or leveling process, these protrusions imprint the sheet surface with numerous deformed and hardened micro-dents, producing a laser-textured sheet. This innovative surface structure preserves the base material’s toughness while introducing countless fine, uniformly distributed hardened points. This creates a surface that combines rigidity and flexibility, offering the following advantages:
Superior Roll Surface Properties:
Laser texturing produces evenly distributed arc-shaped protrusions with significantly higher hardness and strength compared to other texturing methods. It also minimizes residual stress concentration and loss of toughness, extending the service life of the roll.Enhanced Rolling Performance:
The textured surface improves friction and contact conditions between the roll and the sheet, facilitating smoother rolling operations. This allows for increased reduction rates and rolling speeds, reduces scratching and adhesion, improves sheet shape, and enhances surface quality.Improved Forming and Coating Quality:
The micro-dents on the sheet surface act as reservoirs for oil and coolant, improving lubrication and reducing friction during forming. This promotes material flow and eases the forming process. Additionally, these micro-features trap metal debris generated during forming, reducing surface scratches and improving workpiece quality. The texture also enhances coating adhesion and painted surface brightness, increasing product value.
