used 1250mm 6 hi reverse cold rolling mill, model No.:207, it is written on Jan.5,2022

A. Basic information

1. Equipment name: MSB-6C-1250 six high reverse cold rolling mill

2. Purpose of the unit: the unit has a thickness of 2.0-4.5mm, a width of 800-1270mm and a material of the hot rolled strip of low carbon steel and medium and low grade silicon steel is rolled in necessary passes with a thickness of 0.20 ~ 1.2mm.

The product quality of the cold rolling mill finished products shall not be lower than that of GB / T716-1991, GB / T5213-2001,the highest standard of GB / T2521-1996.

B. Main performance parameters of the unit

   2.1 incoming material specification

      Material: pickling hot rolled coil: low carbon steel, medium and low grade    silicon steel, etc

      Mechanical properties: maximum yield limit σ_S≤360N/mm

      Thickness: 2.0-4.5 mm

Width: 800-1270 mm

Coil inner diameter: Φ 610 mm

Coil outer diameter: Φ 800- Φ 2000mm

Unit maximum coil weight: ≤ 20kg / mm

Coil weight: Max 25T

  2.2 finished product size

Thickness: 0.20-1.2mm

Width: 800-1270mm

Coil inner diameter: Φ 610 mm

Coil outer diameter: Φ 800- Φ 2000mm

Coil weight: Max 25T

  2.3 main technical parameters

   1. Main rolling mill

Mill model: MSB-6C-1450

Maximum rolling pressure: 20000KN

Maximum rolling torque: 150KNm

Rolling speed: 0 ~ 1000m / min

Threading speed: 18m / min

Uncoiling speed: 400m / min

Uncoiling tension: 70KN

Maximum coiling tension: ≤ 10m / s 20 ~ 200KN

                           ≥10m/s 12.5～125KN

Uncoiler drum diameter:   Φ 620mm (round Φ 610)

Coiler drum diameter:     Φ610 mm／Φ590 mm (full circle Φ610)

Work roll size:           Φ400 mm／Φ360 × 1450 mm

Intermediate roll size:      Φ450 mm／Φ410 × 1400 mm

Support roll size:          Φ1250 mm／Φ1190 × 1350 mm

Traverse of intermediate roll:  330 mm

Opening:   25m

Bending force of work roll:    + 400kN / - 300KN

Bending force of intermediate roll:    + 400kN

Main drive motor:        4 × 1250KW （0～1000m／min）

Coiler motor:       2 × 2 × 1250KW （0～1000m／min ）

Uncoiler motor:    618kw

Pressing mode:     hydraulic pressing

Product accuracy:     ≤± 1.5% H

Process lubricating medium:   emulsion

Process lubrication flow:   100,00l / min

Working mode of the unit:   coil reversible rolling

Uncoiling direction of the unit:   right uncoiling (facing the operation side of the rolling mill, and the uncoiler is on the right side of the main rolling mill)

2. Uncoiler

Drum:   nominal diameter φ 610mm

Maximum speed: 400m / min

Tension: Max.70 kN

Transmission motor power: 618kW × 1 set (DC)

3. Coiler before and after rolling mill

Drum: φ 610mm

Speed: ≤ 600m / min. (tension: max.200 kN)

Speed: ≥ 600m / min. (tension: max.125 kN)

Power of transmission motor: 1250kW × 2 sets (DC)

2.4 product outline (provided by the buyer)

Steel grade   and specification(mm)	Low   carbon steel, medium and low grade silicon steel		Plate   width
	%	10,000 tons	1,250
	0.35	10	2
	0.50	80	16
	0.65	10	2
total	1.5	100	20

2.5 output calculation of rolling mill

(1) Rolling mill capacity calculation.

(2) Refer to the rolling table for the calculation of each specification.

    2.5.1 working conditions

(1) Skilled operator.

(2) Stable and qualified raw materials.

(3) Sufficient spare parts to ensure continuous production.

   2.5.2 calculation premise

(1) Maximum speed: 1000m / min;

(2) Representative material 50W540;

(3) The unit average coil weight is 20kg / mm;

(4) The specific specification calculation for reference is shown in table 1-5 of the rolling specification:

(5) Excluding the inspection operation of strip steel surface;

(6) The pre uncoiling of the steel coil on the uncoiler and the threading time of the upper channel are not considered.

  2.5.3 rolling time

(1) Calendar time of one year (Tc): Tc = 365 days × 24 h / day = 8760 h / y

(2) Planned maintenance time: 26 times × 16h＝416 h/y (including backup roll change)

(3) Overhaul time: 12 days × 24 h＝288 h/y

(4) Work roll and intermediate roll change: 3 times × 335 days × 0.25 h=251 h/y

Unit shutdown time: Σ＝ 416+288+251=955 h/y

Unit working time (Tw): Tw ＝ 8760h-955h ＝ 7805 h / y

(5) Net working time (Tr)

Net working time (Tr) = unit working time × Unit efficiency

(unit operation rate includes unforeseen shutdown time, such as belt breaking time)

Tw＝7805 × 0.83＝6500 h/y