JPS5935806A - Rolling method - Google Patents

Abstract

PURPOSE:To control easily the shape of a rolling material, by using variable crown rolls as backup rolls and providing plural stands of multiple roll mills whose work rolls are made small in diameter for constituting a continuous rolling equipment. CONSTITUTION:Variable crown type rolls are used as the upper and lower backup rolls 1, 1 and 2, 2 of a multiple rolling mill, and also the work rolls are made small in diameters. Or the lower and upper backup rolls 1, 2 are formed into different variable crown shapes, or work rolls of different peripheral speeds are constituted by making the work rolls small and different in diameters. Thus the shape and the profile or a rolling material are easily controlled by using a continuous rolling equipment equipped with plural stands of said multiple rolling mills.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling method that significantly enhances the shape control effect.

Comparing the advantages and disadvantages of recent rolling methods, we find that (1) each has considerable advantages (1), but on the other hand, it also has some disadvantages. development is desired.

Among various rolling methods, variable crown roll (hereinafter referred to as
It's called VC role. ) has been shown to be relatively effective in meeting various requirements. However, even this method had some drawbacks in terms of control performance and performance under strong pressure.

Next, Table 1 shows a comparison of the advantages and disadvantages of typical conventional rolling methods.

Table 1 In Table 1, HC mill refers to the workpiece of a conventional four-layer rolling mill.
This is a new type 4, 6-layer rolling mill that has an intermediate roll between the roll and backup roll, and by shifting the intermediate roll in the axial direction, changes the deflection of the work roll to control the crown and shape of the copper strip. .

The Pv mill controls the crown and shape of the copper strip by reducing the rolling load component caused by friction during rolling by varying the circumferential speeds of the upper and lower work rolls.

The NMR mill is a combination of a conventional four-layer rolling mill and a Sendzimir multi-stage mill, which enables strong rolling reduction and a high degree of crown and shape control.

An object of the present invention is to obtain a rolling method that exhibits excellent effects on all of the items listed in Table 1.

The basic idea of the present invention is to use a VC roll as a backup roll in a multi-mill of 5 or more layers, to reduce the diameter of the work roll, and to control the pressure, shape, and profile of the multi-layer mill. A plurality of 8 stands are installed in the continuous rolling equipment.

As work rolls become smaller in diameter, it is also effective to incorporate different circumferential speed rolling.

For the VC roll, the pressure chamber is divided into multiple parts in the longitudinal direction,
Appropriate shape control can also be performed by appropriately combining these VC rolls.

In rolling mills in which multiple rolls circumscribe the circumference of one roll at the same time (for example, cluster mills, Sendzimir mills, etc.), VC rolls are used as circumscribing rolls, and small-diameter workpieces and
By combining the roll effect, the shape control effect can be significantly enhanced. The variable crown effect is greater when using small diameter workpieces and rolls. Even for strong rolling, it is more effective to use a combination of small-diameter work rolls and rolling at different circumferential speeds.

As the diameter of the work roll becomes smaller, the deflection of the roll becomes VC.
It becomes easier to follow the swollen shape of the roll. Therefore, by introducing a different type of VC roll (one with a different number of pressure chamber sections in the longitudinal direction) and giving it a complex roll deflection that was previously impossible, we significantly improved the shape and sheet profile control function. I can do it.

Next, examples of the rolling method of the present invention will be described.

<Example 10> (1) Rolling line: Hot rolling line (2) Finished rolling dimensions: Thickness, 8mm x width 120Q+i
m x weight 25 tons (3) Mill used: cluster mill (Fig. 1 (A)) (4
) Work roll: Small diameter different circumferential speed roll (Fig. 1 (B
)) (5) Backup role: All 4 VCs
Roll (6) rolling reduction rate: 90% (at 5 stands) (force
Effect 2: Compared to rolling with a normal 4-layer mill, the rolling load is less than 30%, and in addition to improving strong rolling performance, the shape control ability has been doubled by halving the area in which the roll bender is used.

<Example 2> - (1) Rolling line: Cold rolling line (2) Finished rolling dimensions: Thickness 1.01 x Width 1250 mm x Weight 45 ton (3) Mill used Two cluster mill (4) Work Roll: Small diameter roll (Fig. 2 (A)
, (B)).

Small diameter different circumferential speed roll (Fig. 2) (C), (D)).

(5) Buffer tumerol: Different types of VC rolls 1 and 2 shown in FIG. 6 were used. The VC roll sea-1 has no partition in the pressure chamber 11, and the VC roll 2 has the pressure chamber 12 divided into two longitudinally. This VC roll is used in a roll device as shown in FIG. In FIG. 2, roll 6 is a normal roll.

(6) Reduction rate near 5% (at filter stand) (7) Effect-V
When only the C roll 1 is used, the shape of the rolled material only changes from ear waves to medium elongation, and it is not possible to deal with cases where medium elongation and ear waves occur together near the weld. However, when different types of VC rolls 1 and 2 were used, the crown shapes of both became as shown in FIG. 4, so that when VC roll 2 was operated, the middle elongation and ear wave were eliminated.

When the G virol was further worked under good rolling conditions, quarter elongation (elongation that occurs approximately % from both edges of the rolled material in the width direction) occurred. From this, it is possible to conversely control the quarter elongation. Example 6 In Example 2, when rolling was carried out with the speed difference between the two lower work rolls equal to the rolling reduction ratio, the rolling load was 20~ 3
0% reduction.

<Example 4> (1) Rolling line: cold rolling line. 5 stands.

The first stun l-' is the mill of Example 1. (Fig. 1 (B)). The mill of Example 2 (second The configuration is shown in Figure (D)).

(2) Finished rolled dimensions: thickness 0.5Wm x width 11000
fl1 x heavy leaf 4 Q ton (3) Mill used: Cluster mill (4) Reduction rate of 282% (5) Effect: Conventionally, material thickness of 2.6 mm was rolled only to a finished product thickness of Q, 5 mm. However, in this example, it became possible to strongly reduce a material with a thickness of 2.8 m to a finished product thickness of about 0.5 m.

Due to the influence of the small diameter work roll on the entry side of the first stand, the plate profile has been improved by 8μ and edge drop by 7μ for a nominal width of 1000m, and quarter elongation, which could not be dealt with in the past, has been drastically reduced, resulting in a significant improvement in flatness. It was planned.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a cluster mill to which the rolling method of the present invention is applied. FIG. 2 is a schematic explanatory diagram of an embodiment of the present invention. FIG. 6 is a schematic explanatory diagram of a VC roll applied to the method of the present invention. FIG. 4 is a graph showing the crown shape of the VC roll shown in FIG. 6.

Claims (3)

[Claims] (1) A rolling method characterized in that a variable crown roll is used as a backup roll in a multilayer mill of 5 or more layers, the diameter of the work roll is reduced, and a plurality of stands of the multilayer mill are installed in continuous rolling equipment. (2) The work rolls are configured to have different circumferential speeds, and different circumferential speed rolling is incorporated.
) Method described in section. 3. The method of claim 1, wherein the variable crown roll is configured with different variable crown shapes and incorporates shape profile control.