Brief introduction

The 18-high reversible cold rolling mill has been continuously improved, and the technology has become mature for applications. It is widely used in cold rolling substrates of ultra-thin and wide galvanized sheets, tin-plated sheets and cold rolling of stainless steel sheets and strips. The ultra-thin and wide-width strip steel required by the market has been cut to 0.1mm, and the conventional four-high and six-high rolling mills cannot meet the thickness requirements, and the twenty-high rolling mills are expensive in the initial investment and maintenance. The eighteen-high mill is very suitable for the production of this kind of product and is cost-effective.

The 18-high reversible cold rolling mill unit has the characteristics of high speed, stability and high yield. It produces stainless steel strip with a minimum rolling thickness of 0.25mm and a speed of 800m/min. The intermediate roll of the 18-high reversible cold rolling mill has the functions of traverse and roll bending to control the shape of the roll. The energy consumption per ton of steel of the 18-high reversible cold rolling mill is 20% of that of traditional cold rolling equipment, and its performance has reached the international leading level. The eighteen-high reversible cold rolling mill has a wide rolling range, and the rolling widths are 720mm, 850mm, 1150mm, 1380mm, 1450mm, 1810mm, 2250mm, etc.; the maximum thickness can be rolled to 18mm.

Cold Rolling Mill

1. The composition and structural characteristics of 18 high reversible cold rolling mill:

The 18 high reversing cold rolling mill unit is composed of loading car,  payoff roll, head straightener, right recoiler, unload car, front device, 18-high RCRM, lifting cover, roll changing car, backup roll changing car, rear device, left recoiler, and belt wrapper, etc. .The roll cluster consists of backup rolls, intermediate rolls, work rolls, and 6 side backup rolls on both sides.

The 18 high reversible cold rolling mill consists of backup rolls, intermediate rolls, work rolls, and 6 side backup rolls distributed on both sides. The sequence of roll arrangement is 1, 3, 5. Among them, The layout of main rolls is similar to the 6 high rolling mill, so it can also be used as a"6 high rolling mill with side backup rolls". However, the diameter of the work roll of 18 high cold rolling mill is far less than the 6 high rolling mill, so 18 high rolling mill has prominent advantages. The work roll of 18 high rolling mill has no bearing. When rolling, the work roll is positioned by intermediate rolls, side backup rolls, and the work rolls balance from all directions. The end of the middle roll has a taper, which can move in axis direction. The two rows of the outer row of the side backup rolls are composed of multiple back lining bearing. The side backup rolls and the intermediate rolls are installed in the same roll box.

Generally, the surface to diameter ratio of work roll of 4-high rolling mill is 3-4 while the ratio of 18-high rolling mill is 10, which means that the diameter of the work roll of 18-high rolling mill is about 1/3 of that of ordinary 4-high rolling mill.The composition of 18-high reversible cold rolling mill unit
1-payoff roll 2-head straightener 3-front recoiler 4-front device 5-18 high RCRM 6-rear device 7-rear recoiler 8-belt wrapper

Cold Rolling Mill

2. The advantages of the 18-high reversible cold rolling mill:

 

• The large reduction and small rolling force of each rolling pass result in low energy consumption of 18-high reversible cold rolling mill;
• The 18-high reversible cold rolling mill can produce extremely thin and hard-rolling alloy strip;
• Work roll is light weight and made of special alloy material;
• Work roll is easy to regrind;
• The intermediate rolls positioning between work rolls and backup rolls have a certain taper and axial adjustment, which have the advantages of the HC rolling shape control. With the different width, the intermediate rolls can be appropriately adjusted in axis to make the flat part of rolls inside the internal side of the strip, eliminating the impact of the harmful contact part, avoiding the excessive deflection of work rolls, and achieving the purpose of controlling the edge waves, thereby ensuring good shape.

Glimpse Technology has mastered the core technology of precision high-speed cold rolling mill, and cooperate with first-class professional companies, universities and research institutes at home and abroad (such as China Erzhong, MCC Shaanxi, Tianchuan Institute, Shanghai Baosight Software, Yuci Oil Research Institute, Yanshan University, Wuhan University of Science and Technology, Alstom, Germany, etc.). We wholeheartedly provide customers with solutions for 18-high reversible cold rolling mills, one-stop consultation, planning, design, installation, commissioning, training and other engineering general contracting and mechanical professional subcontracting of stainless steel, carbon steel and non-ferrous metal strip cold rolling projects. Welcome to call us for consultation and cooperation!

Glimpse Technology mainly provides metal sheet and strip rolling equipment: multi-roll continuous rolling mill, 20-high reversible cold rolling mill, 18-high reversible cold rolling mill, 14-high reversible cold rolling mill, and 12-high reversible cold rolling mill, offset eight-high rolling mill, six-high reversible cold rolling mill, four-high reversible cold rolling mill, etc.; strip processing line: continuous annealing line, push-pull pickling line, tension leveling line, rewinding line, multi-roll hard precision stainless steel Straightening unit, leveling unit, online finishing machine, stainless steel strip grinding machine, etc.; silicon steel production technical consultation, silicon steel production line equipment supply; technical transformation and technical consulting business of carbon steel, stainless steel and other cold rolling production lines.
Cold Rolling Mill

3. Typical unit: 1250mm 18-high reversible cold rolling mill

The 18-high reversible cold rolling mill is composed of load car, payoff roll, head straightener, right recoiler, unload car, front devices, 18-high rolling mill, lift cover, roll changing car, backup roll changing car, rear devices, rear devices, left recoiler, belt wrapper, etc..
 

1. The main technical parameters of 1250mm 18-high reversible cold rolling mill unit:

• Maximum rolling force: 12000KN
• Maximum rolling torque: 60kn.m
• Rolling speed: 0 ~ 380 ~ 900m/min
• Maximum threading speed: 0 ~ 30m/min
• Maximum payoff speed: 350m/min
• Maximum coiling speed: 950m/min
• Payoff tension: 6-60kn
• Coiling tension: 14-140kn
• Work roll size: φ170 ~ φ140 x 1250mm
• Intermediate roll size: φ370 ~ φ345 x 1250mm
• Backup roll size: φ1000 ~ φ900 x 1200mm
• Side roll size: φ168 ~ φ165 x 1085mm
• Diameter of payoff mandrel: φ520-508-460mm
• Diameter of coiling mandrel: φ485-508mm
• Maximum opening of work rolls: 20mm
• Positive/negative bending force of intermediate roll (single roll unilateral): 320/200kn
• Traverse of intermediate roll: 200mm
• Hydraulic transmission system pressure: 10MPa
• Bending, traverse system pressure: 28MPa
• Screw up system pressure: 28MPa
• Process lubricant: 7500L/min
• Main rolling motor: DC 1250KW 4 units
• Left and right coiling motor: DC 1250KW 4 units
• Payoff motor: DC 383KW 1 units
• Total capacity of the unit equipment: DC 10416kW

2. The characteristics and installation level of 1250mm 18-high reversible cold rolling mill

• The reversible rolling method of small diameter work roller and side roller to ensure the roll rigidity requirements during rolling and meet the rolling of extremely thin band materials.
• Full-hydraulic screw up and hydraulic AGC automation control. It has functions of constant pressure control, seconds flow control (when the laser speed measuring instrument is used) and roll adjustment, gauge pre-control, monitoring, etc. The hydraulic AGC uses Siemens TDC controller and interface module to meet the real -time control requirements of the system.
• The entire control system adopts computer control technology, full digital DC speed regulating device, decentralized PLC unit process control and remote communication networking technology, and human machine interface (HMI) to unify the interface relationship of each system, thereby constitute a modern rolling mill wholly automation control system.
• The main operating table has a human -machine interface to display the state of the rolling machine (rolling power, tension, current, speed and other main process parameters) and manual adjustment, rolling process parameters setting, fault alarm and print reports.
• The upper and lower intermediate rolls are driven separately, exempting the requirements of matching roll within a certain range.
• he intermediate roll system has the control of positive and negative bending force, and can be controlled unilaterally.
• The traverse preset of intermediate roll system.
• The rolling line elevation can be adjusted steplessly by adding wedge by step.
• Work rolls and intermediate rolls can be quickly replaced.
• The automatic CPC of payoff roll uses CCD product.
• The bearings of intermediate roll, side backup rolls and backup rolls are lubricated by aired oil, and bearing of work roll is lubricated by dry oil.
• The thickness gauge of the unit adopts a domestic X-ray thickness gauge; the tension detection of the front and rear of the mill is conducted by ABB tension gauge; the speed measurement of the unit adopts an imported laser tachometer, and is equipped with a German P+F encoder for speed measurement; the proximity switch adopts German SICK products
• The electrical system of the rolling mill has safety protection measures such as overload protection, broken belt protection and emergency stop; the unit has the functions of automatic deceleration of the belt tail and accurate stop; the coiler has the functions of lap memory, belt length calculation and accurate positioning of the jaws
• The production process interlock and fault alarming of the unit use TDC controller to realize the automation of production processes and fault alarm automation.
• The hydraulic transmission system hydraulic pump and main components use imported products; the AGC system, bending roller and side roller system hydraulic pumps, main components and sealing parts are imported products.
• The process lubrication system is set up with magnetic filtration, mixing device, sliding device and vacuum filter device.
• The reducer of the heavier -loading of important driver equipment such as payoff roll, recoiler, and the main rolling mill use surface hardening gear and core shaft uses alloy forging steel;

Cold Rolling Mill
Keywords: 18-high rolling mill, 18-hi crm, eighteen high rolling mill