Введение
А tandem cold rolling mill process adopts state-of-the-art layout technology for modern cold rolling production. It effectively meets the growing demands for high production capacity and premium quality of cold-rolled strip products. This article takes the classic 1700mm five-stand cold rolling unit as an example to elaborate on the complete and standardized tandem cold rolling mill process.
1. Coil Feeding Procedure in Tandem Cold Rolling Mill Process
Workers use overhead cranes to transfer pickled hot-rolled strip coils from the intermediate coil warehouse. These coils rest on bracket stepping beams that stand perpendicular to the rolling line. The stepping beams precisely deliver steel coils to dedicated coil trolleys. Photoelectric sensors and positioning devices achieve automatic coil centering. Следующий, a strapping machine cuts and shreds coil straps. The trolley then moves the steel coil to the pre-uncoiling position along the rolling direction.
A strip head detector accurately locates the strip front end. A scraper lifts the strip head and sends it into a three-roll straightener. The strip head passes through the strip holder, and pinch rolls clamp it firmly to finish pre-uncoiling preparation. After finishing this step, scrapers and lower straightener rolls retreat to the transmission side. The steel coil waits in place for subsequent uncoiling and threading operations.
2. Uncoiling and Threading Process
Once the previous strip tail fully exits the double-cone telescopic uncoiler, the uncoiler drum contracts and separates axially. The feeding trolley delivers new steel coils and sleeves them on the uncoiler drum. This step officially starts the threading work of the tandem cold rolling mill process.
Pinch rolls send the strip head into the roller press device. When the strip enters the rolling mill, press rollers compress the strip tightly. This operation avoids strip wrinkling and builds stable back tension for rolling. Тем временем, the strip deviation correction system automatically activates after tension forms between the uncoiler and the first stand. It keeps the strip centered throughout the rolling process.
Operators control the threading speed steadily at 1 к 2 метры в секунду. The strip passes through each stand roll in sequence. The whole threading process completes once the strip head enters the coiler mandrel and builds stable outlet tension.
3. Precision Rolling Process
Precision rolling serves as the core stage of the tandem cold rolling mill process. Workers start all automatic control systems before mill acceleration. These systems lay a solid foundation for high-precision rolling.
The production line installs gamma-ray thickness gauges at key positions. These positions cover the gap between the uncoiler and the first stand, every adjacent rolling stand, and the area between the fifth stand and the coiler. The gauges monitor strip thickness in real time. Magnetic tension measuring rollers at each interval continuously detect strip tension to maintain stable tension control. The hydraulic screw-down system strictly controls thickness tolerance during acceleration and stable rolling stages.
Each rolling stand equips with independent hydraulic roll bending devices. These devices adjust roll contours and correct various strip flatness defects. The entire production line runs fully automatically during stable rolling. Operators only monitor equipment operating status and rarely conduct manual intervention.
4. Tail-out Control Process
The mill automatically reduces stable rolling speed to tail-out speed when the strip tail approaches the rolling end. This tail-out speed keeps consistent with the conventional threading speed. After the strip completely separates from the uncoiler, the pressing plates of each stand compressor act in order.
This operation maintains continuous and stable back tension on the strip tail. It effectively prevents strip jumping, deviation and breakage during tail-out production. It also ensures full and stable rolling of the entire steel coil.
5. Coil Unloading and Warehousing Process
The unloading trolley rises immediately after the strip tail fully exits the last rolling stand. The coiler stops running automatically and contracts its drum. The trolley unloads the finished steel coil and places it on the saddle of the output stepping beam.
The stepping beam transports the steel coil to the weighing platform for accurate weight measurement. It then sends the qualified coil to the strapping machine for automatic bundling. Окончательно, the stepping beam transfers the finished coil to the terminal position, and workers deliver it to the finished product warehouse for storage.
Заключение
Полный tandem cold rolling mill process includes five core steps: coil feeding, uncoiling and threading, precision rolling, tail-out control, and coil unloading. Equipped with integrated automatic control systems for thickness, tension and flatness, the five-stand tandem cold rolling mill delivers high precision, stable performance and high efficiency for modern cold-rolled strip steel production.