High Precision Reversing Cold Rolling Mill for Carbon & Stainless Steel - China Suppliers & Factory
The Theory of Six Roll Rolling Mill
Six roll rolling mill adds a pair of middle roller that can move symmetrically and axially, eliminating the harmful contact between working roll and support roll. During milling, for different width of steel strips will use different movement amount of middle roll, change the contact pressure distribution (flattening value distribution) between rollers and bending force, so to control the plate shape and convexity.
Product Introduction
The six-high reversing cold rolling mill is a high-precision metal rolling equipment, mainly used for multi-pass rolling of strip materials at room temperature to achieve thickness reduction, plate shape control and surface quality improvement.
The core feature of this equipment lies in its six-high structure design and reversible rolling function. It consists of six rolls including work rolls, intermediate rolls and backup rolls, among which the intermediate rolls can move axially (oscillate), and the work rolls are equipped with hydraulic bending roll devices. This design can effectively adjust the pressure distribution between the rolls and improve the accuracy of plate shape control; the reversible rolling function allows the strip to be rolled back and forth in the mill, ensuring thickness uniformity.
High precision, strong adaptability and high efficiency. Suitable for stainless steel, common steel, aluminum and copper — rolling raw materials from 1.5–4.5 mm down to finished products of 0.15–2.0 mm. Rolling accuracy reaches ±0.02 mm, with rolling speeds from 360 to 1000 m/min.
The equipment is often integrated with hydraulic systems, automatic control systems and auxiliary devices (such as uncoilers and thickness gauges) to achieve automated operation.
Typical application scenarios include cold rolling lines for strip steel and deep processing of metal materials. For example, a 1400 mm specification equipment has a maximum rolling force of 12000 kN, suitable for wide strip rolling, and is widely used in the automotive, home appliance, energy and other industries for the demand of high-precision metal strips.
Technical Parameter Table
| Mill Model / Technical Parameter | 950 | 1150 | 1380 |
|---|---|---|---|
| Material | Carbon steel and low alloy steel | Carbon steel and low alloy steel | Carbon steel and low alloy steel |
| Material Thickness (mm) | 2.0 ~ 3.5 | 2.0 ~ 4.0 | 2.0 ~ 4.0 |
| Material Width (mm) | 600 ~ 850 | 900 ~ 1050 | 1000 ~ 1250 |
| Finish Thickness (mm) | 0.5 ~ 0.15 | 0.5 ~ 0.16 | 0.5 ~ 0.18 |
| Pressing Force (KN) | 9000 | 13000 | 15000 |
| Support Roll Specification (mm) | Φ800×920 | Φ1050×1120 | Φ1100×1350 |
| Middle Roll Specification (mm) | Φ350/Φ320×900 | Φ380/Φ350×1150 | Φ380/Φ350×1350 |
| Working Roll Specification (mm) | Φ260/Φ235×950 | Φ310/Φ280×1150 | Φ280/Φ255×1380 |
| Driving Method | Working roll driving | Working roll driving | Working roll driving |
| Main Motor | DC 1250KW×2 | DC 1000KW×4 | DC 1250KW×4 |
| Speed Reducer | Joint gear box | Joint gear box | Joint gear box |
| Uncoiler (Specifications) | Φ610×950 | Φ610×1150 | Φ610×1380 |
| Recoiler (Specifications) | Φ508×950 | Φ508×1150 | Φ508×1380 |
| Rolling Speed (m/min) | 800 | 900 | 900 |
| Uncoiler Tension (KN) | 45 | 70 | 70 |
| Recoiler Tension (KN) | 9 ~ 90 | 14 ~ 140 | 17 ~ 170 |
| Pressing Method | Hydraulic AGC | Hydraulic AGC | Hydraulic AGC |
| DC Speed Regulator | Siemens 6RA70 | Siemens 6RA70 | Siemens 6RA70 |
| Electric Control | Siemens PLC | Siemens PLC | Siemens PLC |
⚠️ Remark: The model and parameters shown in this table are for reference only. The design and production can be tailor-made according to user's requirements.
Frequently Asked Questions (FAQ)
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Q1 What is a six-high reversing cold rolling mill and how does it differ from a four-high mill?A six-high reversing cold rolling mill features six rolls — work rolls, intermediate rolls and backup rolls — whereas a four-high mill uses only work rolls and backup rolls. The additional pair of intermediate rolls in the six-high configuration can move axially, allowing for more precise control of strip shape, pressure distribution, and crown, making it ideal for high-precision thin-gauge rolling.
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Q2 What materials can be processed on a six-high reversing cold rolling mill?The six-high reversing cold rolling mill is suitable for a wide range of metallic materials, including carbon steel, low alloy steel, stainless steel, aluminum and copper. It is especially well-suited for applications requiring high surface quality and tight thickness tolerances.
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Q3 What thickness range can be achieved with this rolling mill?The equipment can process raw materials with entry thicknesses ranging from 1.5 to 4.5 mm and roll them down to finished thicknesses as thin as 0.15 mm, with a rolling accuracy of ±0.02 mm. Specific thickness ranges vary slightly depending on the mill model (950, 1150, or 1380).
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Q4 What is the function of the axially movable intermediate rolls?The intermediate rolls can shift axially (oscillate) to match different strip widths. This movement changes the contact pressure distribution between the rolls and, combined with hydraulic bending roll devices on the work rolls, allows for precise control of plate shape and strip convexity during rolling.
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Q5 What control systems are used in this rolling mill?The mill is equipped with Siemens 6RA70 DC speed regulators and Siemens PLC-based electric control systems. Rolling gap is controlled via Hydraulic AGC (Automatic Gauge Control) to ensure consistent product thickness across all passes.
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Q6 Can the six-high reversing cold rolling mill be customized to specific requirements?Yes. The mill models and technical parameters listed in the specification table are for reference only. The design and manufacturing of the equipment can be fully tailor-made according to the customer's specific production requirements, including mill width, rolling force, speed, material type and automation level.