Φ450×1500/Φ960×1450㎜ pickling 4-hi skin pass mill

I、Technological requirements

1.Parameters of raw material

CQ、DQ、DDQ、HSS340、HSS440、HSS590

Spec. of raw material：

Thickness：1.5～4.5 mm

Width：900～1300 mm

2. Requirement of raw material：It shall comply with the corresponding national standards.

3.Max rolling force：10000 KN

4.Max rolling speed：180 m/min

5. Max tension at entry/exit side ：about 150 KN

6. Maximum Leveling volume：0.3～0.5mm

7.Direction of the line：To be determined by user.

II、Summary

1. Function of the skin pass mill

It is at the exit section, it has the following main fuctions

1）Achieve the required surface roughness for pickled steel plates to enhance production quality in subsequent processes.

2）To eliminate thickness variations in pickled steel plates.

3）To improve the mechanical properties of pickled steel plates.

2. Key properties

1）Type：4-hi hydraulic pressure down, wet leveling.

2）Transmission Mode：

①The system employs AC variable-frequency motors for drive (two motors in total, driving the upper and lower working rollers respectively).

②Synchronization of upper and lower working rollers and load balance control.

③Closed-loop control of speed and tension.

3）Levelling and rolling mode：

①Constant Rolling Force Mode：AFC

②Extension Rate mode：AEC

4）Switching of pressing control mode: position closed-loop control versus rolling force closed-loop control.

5）working roll bending roll mode ：

①The positive bending roller hydraulic cylinder also serves as the balancing cylinder for the upper working roller.

② working roll positive/negtive bending roll

③The roll bending force can be preset, monitored via feedback, and adjusted in real time.

6）Main control units for the pressing and bending rollers：

① pressing control：servo valve，total 2 pcs

② bending roll control：Proportional valve, 2 pcs。

7）instruments：

① displacement transducer：precision 1μm，It is built into the pressing hydraulic cylinder, total 2pcs.

② pressure transducer： precision 0.2%，total 4 pcs

③Tensile gauge: Accuracy of 0.5%, total 4 pcs.

8）Axial locking method for roller assy: hydraulic locking.

9）Upper support roller balancing method: The balancing hydraulic cylinders on both sides move up and down synchronously

10) rolling line elevation adjusting method: Adjustment using a wedge mechanism

11）adjustment method for the entry side wrinkle-reducing roller

① lifting/falling hydraulic cylinder driving.（2 pcs）

②Dual-hydraulic cylinder gear-rack synchronization

12）Adjustment method for exit anti-bending rollers：

①lifting/falling hydraulic cylinder driving.（2 pcs）

② Dual-hydraulic cylinder gear-rack synchronization

12）working rolls changing method：

Roll changing by gear motor driving without stopping the machine.

14）support roll changing method：

Changing the roll by hydraulic without stopping the machine.