The high speed wire rod rolling mill process is flexible, complete control means, can produce a wide range variety of high-quality wire rods. Twist-free finishing mill units both in production efficiency and product quality are greatly superior to the open-train mill, even in the lower speed range, its performance is better than of the open train mills. High-speed wire rod mills are characterized by high speed, continuous, no-twist and controlled cooling.
The high-speed no-twist finishing rolling process can realize multiple product specifications, high sectional dimensional accuracy, large coil weight and high productivity, and also can solve the problem of temperature drop during the rolling of large coil. The high speed of fine rolling requires no twisting of the rolled parts during rolling, otherwise rolling accidents occur frequently and the rolling process cannot be carried out. The main factors influencing high-speed rolling are the quality of raw materials, rolling precision, rolling temperature and process equipment. It needs to control the size accuracy of the billet in order to ensure the accuracy of the rolled parts. Meanwhile, the temperature of the rolled parts shall be uniform and stable, the mill seat has good rigidity and precision. Usually the deviation of the rolled piece into the finishing mill is not greater than ± 0.30mm, when the finished product accuracy requirements less than 士0.15mm, deviation of the rolled piece should not be greater than twice the size deviation of the finished product. Tension between the mill has a great impact on the accuracy of the rolled parts, and should be achieved as far as possible without tension and micro-tension rolling.
When the rolling speed exceeds 75m /s, the temperature of the finished product is high, the water-cooled section of the accident will increase. High rolling speed causes that can't reach cooling control requirements in the water-cooled section. As high-speed mill run continuously, the final rolling temperature is higher than the ordinary mill, natural cooling mode will cause serious secondary oxidation, the mechanical properties of the wire are low and seriously uneven.
For high speed wire production line, the cooling rate of the finished products are controlled by stages, that can minimize the amount of secondary oxidation of the rolled parts, according to the chemical composition of steel and performance demand, the rolled parts under loose coil turn from the high temperature austenite organization into the corresponding metallographic structure at room temperature.
