The 1780mm hot rolling project took 15 months from the start of construction to the completion and commissioning. .The whole hot rolling line adopts 2 walking beam reheating furnace, a reversible four-high roughing mill, 8 four-high continuous finishing mills and 2 horizontal coilers. The whole line of equipment integrates the most advanced technology. At the same time, investment in environmental protection facilities has been increased. The production line actively implements coal-to-gas conversion, and adopts advanced flameless burners to make temperature control more accurate and reduce nitrogen oxide emissions, which can achieve high-quality and efficient production at the same time. Clean manufacturing.
After the slab comes out of the reheating furnace, under the conveyance of the roller table, it quickly reaches the rough rolling mill. The rough rolling mill adopts four-high reversible rolling, with automatic width control function and short stroke control function to control the width deviation of the full length of the intermediate slab. And control the shape of the head and tail of the strip to achieve precise control of the width of the strip. After repeated rolling in the roughing mill, the thickness of 200mm is rolled to an intermediate plate with a thickness of about 30mm. Through flying shears and shearing, the irregular areas of the head and tail are cut off. In this process, an accurate rolling tracker (thermal detector) is used to track the entire roller table, and the shearing accuracy is controlled at 10mm within, effectively improve the output rate. Reduce product energy consumption
Finally, enter the key link of the finishing mill. The finishing rolling unit is the core of the whole production line. It has several major features: the control precision of finishing rolling is relatively high. It can be seen from the speed curve that the maximum finishing rolling speed can reach 18 meters per second, which belongs to continuous rolling. Finishing rolling can directly roll the thickness of the product from 30mm to 2mm, and the eight brackets pass through at one time
The whole shape control is made of high-speed steel rolls, and the high-speed steel rolls are controlled with a certain shape and shape, so that the final product can meet the shape requirements of downstream customers. Conventional rolls may only roll one rolling plan, which cannot meet production needs, and need to be replaced with new ones. The rolling schedule of high-speed steel rolls is eight times that of ordinary rolls, which greatly saves downtime, increases production output, and improves product quality.
High-speed steel rolls can not only improve the grinding rate of the rolls and reduce the scrap rate, but also control the size of the strip more precisely, and the thickness deviation can reach within 300 microns.
The hot steel strip coming out of the last rolling mill of the finishing rolling is cooled to the set temperature, and then coiled into a steel strip coil by the coiler, and the whole process only takes 2 minutes.
The 1780mm hot continuous rolling production line is computer-controlled, mechanized and automated, with large production scale and low energy consumption.