The high-speed wire rod rolling mill process is highly flexible, equipped with comprehensive control systems, and capable of producing a wide variety of high-quality wire rods. Twist-free finishing mills significantly outperform open-train mills in both production efficiency and product quality. Even at lower speeds, their performance remains superior. High-speed wire rod mills are characterized by high production speed, continuous operation, twist-free rolling, and controlled cooling.
The high-speed, no-twist finishing rolling process enables the production of various product specifications, with high dimensional accuracy, large coil weights, and high productivity. It also addresses the issue of temperature drop during the rolling of large coils. Due to the high rolling speed, the rolled parts must not twist during the process, as twisting may cause frequent rolling accidents and disrupt production.
Key factors influencing high-speed rolling include raw material quality, rolling precision, rolling temperature, and process equipment. To ensure the accuracy of the final rolled product, the billet’s dimensional precision must be strictly controlled. The temperature of the rolled material must remain uniform and stable, and the mill stands must possess high rigidity and precision. Typically, the deviation of the rolled piece entering the finishing mill should not exceed ±0.30 mm. When the required accuracy of the finished product is within ±0.15 mm, the deviation of the rolled piece should be no more than twice the allowable deviation of the finished product. Inter-stand tension greatly affects the rolling accuracy and should be minimized by adopting no-tension or micro-tension rolling wherever possible.
When the rolling speed exceeds 75 m/s, the high temperature of the finished product increases the risk of incidents in the water-cooling section. At such speeds, it becomes difficult to meet cooling control requirements, resulting in insufficient cooling. Since high-speed mills operate continuously, the final rolling temperature is higher than in conventional mills. Natural cooling may cause severe secondary oxidation, leading to poor and uneven mechanical properties of the wire rod.
In high-speed wire rod production lines, staged cooling of the finished product is implemented to minimize secondary oxidation. Based on the steel’s chemical composition and performance requirements, the rolled product—cooled in loose coils—transforms from a high-temperature austenitic structure into the appropriate metallographic structure at room temperature.
