JPS5853305A - Rolling method for thick plate - Google Patents

Abstract

PURPOSE:To control a nonrectangular material to be rolled surely to a rectangular shape and to improve the yield of product markedly by rolling said material while it is set diagnoally by a prescribed rate with respect to rolling mills. CONSTITUTION:A material 1 to be rolled having a nonsquare shape such as parallelogram is rotated on a plane by a prescribed angle by a rotating and turning device in the midway of broadside rolling of finish rolling. In said state, the material 1 is so disposed and set as to incline by a prescribed rate with respect to a rolling mill 2 and is then carried into the mill 2, by which the material is rolled and a product 5 of a square shape such as rectangular shape is obtained. This method is adaptable for controlling plane shapes of Al and light metals other than steel plates. Here, 3 in the figure denotes side guides.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling a thick plate, and more particularly to a rolling method for controlling the shape of a thick plate during rolling.

Slabs are usually used for rolling thick plates, and are heated to 130 mm in a heating furnace.
After being heated to around 0°C, it is rolled into a predetermined width, thickness, and length using a rolling mill.

In this case, if the slab has a rectangular planar shape, it will remain rectangular after rolling and no yield loss will occur.

However, as shown in FIG. 1, the cut surface of the slab +11 may be cut diagonally by a slab cutter, resulting in a parallelogram. Moreover, when the slab is rolled after being treated, the rolled intermediate plate as shown in FIG. 1 is completed because the slab has been treated with uneven thickness.

Therefore, if the steel plate is rolled as it is, a steel plate (113) with a triangular tip end as shown in FIG. 2 will be completed, and the shaded circle will not be a finished product, resulting in a yield loss.

For this reason, various measures have been taken to prevent uneven thickness and to cut slabs at right angles, but these measures are not perfect and have not yet completely solved the yield loss.

In view of the various shortcomings of the conventional technology, the inventors of the present invention have conducted intensive studies on improvement measures, and have appropriately selected the angle at which the material to be rolled is introduced into the rolling mill. Even if it does not have a rolling process, it will definitely be in a rectangular shape! The present invention was achieved based on the discovery that it is possible to control the

Therefore, an object of the present invention is to provide a method for rolling a thick plate that can improve the yield of thick plate products by rolling a rolled material whose planar shape is not a rectangular isotropic shape into a rectangular isotropic shape. That is, as shown in FIG. 3, the object of the present invention is to rotate a rolled material flJ having an asymmetrical shape such as a parallelogram on a plane at a predetermined angle by a one-turn turn device during width rolling or finish rolling. A method of obtaining a rectangular isotropic semi-finished product (5) by placing the material to be rolled so as to be inclined by a predetermined amount with respect to the rolling mill, and carrying it into the rolling mill (2) in that state and rolling it. It is.

Note that (31 is a side guide for setting the material to be rolled at a predetermined diagonal position.

Next, the theoretical basis of this invention will be explained based on the example shown in FIG. That is, FIG. 4 illustrates the case where a slab (1) having a parallelogram cross section is rolled into a rectangular slab (51) before rolling. When the thickness is t, the interior angles of the parallelogram are q and s
When detected, the side guide (3) is moved at a predetermined interval G, (
2G), turning is performed as shown in the figure before rolling, and rolling is started at an angle θR. row)
Calculate the case where the A and C lines are overlapped at the center of the side guide +31 as an example.

Slab (Ill- et al. p Iiyama W- Plate length L'
.

To obtain a rectangular semi-finished product (5) with thickness t'.

Since the unknown quantity G and θR4W'%L'%t' are indicated by the above-mentioned detected values, rtn is good.

In rolling, the material mainly moves only in the direction of the rolls, so the following relational expressions hold true:

1' WL Ll -02 G=Lcoa(θ8-θR)・・・・・・・・・・・・
・・・・・・・・・・・・・・・・Song... ■Therefore, θR can be found from the above formula. Next, from the above formula G = L cab (θ6-θR), G Find I−)n.

Moreover, [' is expressed by the following formula.

■, From formula 0, L'>” and WJ2・ are each expressed by the following formula -1
In FIG. 4, if AC, 80' is set as e, e', it is expressed as the following equation.

di ,, = Ll, I0wl−・・・・・・・・・
・・・・・・・・・・・・・・・・For playing songs・・・
The song (S■, ■, ■ and 0 formula 1p Qa tang θR° song @ is obtained, and L' can be found.

Also, W' is calculated from the equation (0).

That is, thickness [, Iiyama W, plate length, interior angle θS of parallelogram
The slab can be made into a rectangular slab having a thickness t', Iiyama W', and a plate length. What should be noted here is that the improvement in yield obtained by n is that when W > W, the width is increased by rolling 9, so width rolling is performed prior to implementing the present invention. In this case, it is preferable to roll the material narrowly by the required width v-W-ΔW in advance.

Next, the present invention will be described in detail with reference to examples. ◇ Example 1 Parallelogram slab t XWXL=250X 190 (J
When the internal angle θS of the slab cut to X2500 was measured using a squareness detector before being charged into the billet heating furnace, it was 88.5°.
Met. This slab was heated to 1800℃ in a steel billet heating furnace and extracted, and the side guide width was adjusted to 1531.9X2 (2G
), the slab was rotated on a turntable, and the turn was stopped when both diagonal corners of the slab came into contact with the side guides. When θR was measured, it was 36.3
It was rare at °. Side guide 1531, 9X2 (2G)
The slab was conveyed to a rolling mill while still being set, and rolled down in one bath from t=2.50 rrm to 243.3 rrm. As a result.

t'xW'xL'=243,3X 1909.7X2
A product with a good shape of s 55.8 was obtained. Furthermore, this rolling process ultimately resulted in a 2.0% improvement in yield compared to the conventional rolling method.

Example 2 t XWXL=250X 1900X2500T interior angle θ
s −89° parallelogram slab in a steel billet heating furnace for 120°
Heat to 0°C to extract, and set the side guide width at the front of the rolling mill to (525, 4X2 (2G)).

Operate the turntable to reach both diagonal corners of the slab N3
When contact occurred, turning was stopped at 9 RN, and in this state, the rolling mill bit t = 250 mm → 245.6 tr
Press down to m t'Xw'x L' = 245
．． A product with a good shape of 6×1906, 1×2536.6 was obtained. This ultimately resulted in a 163% improvement in yield compared to conventionally rolled products.

Note that θR was 56.6@.

Example 6 Cut to the same dimensions as the slab of Example 1, θS = 89
．． 5"q) After heating and extracting a parallelogram slab with medium angles to 1200℃ in a steel billet heating furnace, set the side guide width to 1519.1 A part of both corners touched the side guide [Also, the turning was stopped at the stage, and in this state, it was bitten by a rolling mill and rolled down to t' = 247.7. 7X 19
A product with a good shape of 0.05.5 x 2518.8 was obtained. t, 7
% yield improvement was achieved at θR=36.9°.

In the above description, in order to make it easier to understand the present invention, the rolled material is explained using an example of a member having a parallelogram shape, but the scope is of course not limited to this, and each slab or rolled material having a non-rectangular or non-rectangular shape is used. Needless to say, this method can be effectively applied to controlling the planar shape of the front plate.

Furthermore, this invention +1i11 can also be applied to the planar shape control of aluminum and light metals in addition to steel plates.

In this starting BA, the non-rectangular rolled material is fixed into a rectangular shape by the rolling IA-i' with the rolled material set at a predetermined angle with respect to the rolling machine as described above (C control). # It is easy to use, and has the excellent effect of greatly improving product yield.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a parallelogram slab, Fig. 2 is a plan view showing the parallelogram slab;
FIG. 6 is a schematic diagram illustrating the method of the present invention, and FIG. 4 is an explanatory diagram illustrating the rationale for the method of the present invention. 1: parallelogram slab, 2: rolling mill, 3 = side guide, 5: rectangular product. Agent Toge, j, 'Sa) j, E Masanoshi

Claims (1)

[Claims] In the method of rolling a thick plate, between rolling passes, the material to be rolled is rotated by a predetermined amount on a plane on the front or rear side of the rolling mill, and the material to be rolled is set at an angle of a predetermined amount with respect to the rolling mill. A method for rolling a thick plate, which comprises rolling and controlling the planar shape of a material to be rolled.