JPS61165201A - Rough rolling method of bar steel and wire rod - Google Patents

Abstract

PURPOSE:To increase a reduction rate of area in vertical rolling and to perform efficiently the rolling with a small number of stands, by arranging a motor- driving horizontal mill having the roll surface of large friction coefficient and a non-driving vertical mill having the roll surface of small friction coefficient in series. CONSTITUTION:For increasing the friction coefficient muH of the rolls of motor- driving horizontal mills 1, 3, the roll surfaces are worked by knurling or shot blasting. For decreasing the friction coefficient muV of the rolls of non-driving vertical mills 2, 4, on the other hand, the rolls of small surface roughness are used or hot lubrication is performed. As a result, the muH is made to about >=0.5, and the muV is made to about <=0.3. Therefore, the rolling reduction in the non- driving vertical rolling is remarkably increased, and the reduction rate of area is increased into about 0.2-0.4. Accordingly, the number of stands can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the efficiency of rough rolling of long steel and wire rods.

[Conventional technology]

When rolling steel bars and wire rods, the method of rolling using an electric motor-driven horizontal rolling mill and a non-driving vertical rolling mill connected to it is different from the conventional method using an electric motor-driven vertical rolling mill. , only horizontal rolling mills are installed in series to roll the material 9 times.
This method is far superior in terms of equipment cost, equipment space, workability for rearranging roll guides, and product quality compared to the method of turning the roll by 0° and hitting the rolling force. Second
The figure is a block diagram showing a method using the above-mentioned non-driven vertical rolling. In the figure, (1) is an electric motor-driven A1 horizontal rolling mill, (2)
is a non-driven &1 vertical rolling mill, (3) is a driven flat 2 horizontal rolling mill, (4) is a non-driven /111 &2 vertical rolling mill, (5
) is a rolled material.

[Problem that the invention seeks to solve]

By the way, in the above rolling method, the ejection force generated on the rolled material by the driving horizontal rolling mill (1) in the preceding stage of the flat 1 non-driving vertical rolling mill (2) and the pulling force generated in the rolled material by the A2 horizontal rolling material (3) in the succeeding stage. The force is 41 vertical rolling mills (2
) Rolling is impossible unless the push-in and pull-out forces are greater than those required for non-driven rolling.

Therefore, simply placing a non-driven vertically rolled material near a horizontal rolling mill will not improve the rolling effect. In order to increase the cross-sectional reduction ratio of the material and improve the efficiency of rolling, the ejection force and retraction force applied to the rolled material by the horizontal rolling mills before and after the non-driven vertical rolling mill must be sufficiently large. Not sticky. Otherwise, in order to obtain the desired cross-sectional reduction rate, the number of stands must be increased, which may result in less advantages than the conventional method in terms of equipment costs and equipment space. In addition, when the cross-sectional reduction ratio in the vertical rolling mill is much smaller than that in the horizontal rolling mill, the total rolling reduction due to horizontal rolling becomes significantly larger than the total rolling reduction due to vertical rolling.
The dimensions that can be rolled with commonly used plume materials are limited to those with a width that is significantly larger than the height, and the above method cannot be used practically for 1L.

The present invention aims to eliminate the above-mentioned drawbacks of conventional equipment and provide a rough rolling method for long steel and wire rods that increases the cross-sectional reduction ratio of a non-driven vertical rolling mill and improves the rolling efficiency of the entire equipment. .

[Means and effects for solving the problem] The ejection force FH of the rolled material in a general electric motor-driven rolling mill and the pushing force rv required for non-drive rolling are expressed by the following equations (1) and (2). .

Here, P: Rolling load μ: Coefficient of friction between the roll and the rolled material R: Roll radius td: Rolling contact arc length = (i = 5 - Δh: Reduction amount subscript H: Drive horizontal rolling V: Non-drive vertical rolling The experimental results of the ejection force FH and the pushing force FW and the calculated values are shown in FIGS. 3 and 4.

The roll diameter used in the experiment was 120 φ, and the rolled material was 3.
It is pure lead with a width of 0+a and a height of 30W. In the experiment shown in Figure S, the results are shown when the friction coefficient μ■ is 0.3 and 0.5. 6 points are experimental values, and the solid curve is μw.
= 0.3, and the broken line is the calculated value for μm-0.5. Moreover, the 0 point in FIG. 4 is an experimental value, and the curve is a calculated value.

By the way, as mentioned above, non-driven vertical rolling is possible under the condition of Fa>F'v. Therefore, non-driven rolling is possible by increasing PM and decreasing Pv in equations (1) and (2), but on the other hand, decreasing Pv while leaving μV unchanged increases the reduction amount of vertical rolling, that is, the area reduction rate. If you make it smaller, it will not meet the intended purpose. However, P
In order to try to increase only PH regardless of v,
From equation (1), it can be seen that it is effective to increase the friction coefficient μ■. Furthermore, according to rolling theory, in order to reduce PV without changing the amount of rolling reduction, it is sufficient to reduce the friction coefficient μV. Therefore, by increasing μ■ and decreasing μV, it is possible to not only enable non-driven vertical rolling but also to increase its cross-sectional reduction ratio.

[Embodiments of the invention]

In accordance with the above methods, in order to increase μ of the roll of a horizontal rolling mill, the surface of the roll was knurled or knurled, or shot. In addition, in order to reduce the μV of the rolls of a one-sided valve-driven vertical rolling mill, hot lubrication or rolls with small surface roughness can be used.As a result, the conventional friction coefficient in hot rolling 0.35～
While it was 0.40, μ■ could be made to be 0.5 or more, and μV could be made to be 0.3 or less. For this reason, the amount of reduction in non-driven vertical rolling increases significantly, and conventionally 0.10 to 0.
The cross-sectional reduction ratio, which was 15, increased to 0.20 to 0.40. FIG. 1' is a diagram illustrating the increase in reduction in non-driven vertical rolling according to the present invention. The rolled material size at the roll entrance is 10
0 shout width x 100mm height, Ra: 200mXR
v:'1'25 In the data for vm, A is the method according to the present invention, and B is the data according to the conventional method.

[Effects of the Invention] The present invention provides for rough rolling of long steel and wire rods by connecting a driven horizontal rolling mill and a non-driven vertical rolling mill. Since each rolling was performed with a large coefficient of friction between the roll and the rolled material in non-driven vertical rolling, and a small coefficient of friction between the roll and the rolled material in non-driven vertical rolling, it was possible to increase the cross-sectional reduction ratio in non-driven vertical rolling. , it was possible to reduce the number of stands during rough rolling, and to make it possible to manufacture products with arbitrary rolling dimensions from the bloom material.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the reduction amount of vertical rolling by the rolling method of the present invention, Fig. 2 is a block diagram showing the method of rolling steel bars and wire rods,
FIG. 6 is a diagram showing the relationship between discharge force and rolling load in the case of drive rolling, and FIG. 4 is a diagram showing the relationship between pushing force and rolling load in non-drive rolling. In the figure, (1) is the A1 drive horizontal rolling mill (2), and (2) is the A1
Non-drive vertical rolling mill, (3) flat 2-drive horizontal rolling mill, (4
) is a washing 2 non-drive vertical rolling mill, and (5) is a rolled material. Agent: Patent attorney: Sanro Kimura (QM)? Praise ψ ΦΦOC5oC5aΦ 0 0 o o 9 IO? F) To (Yamada) Number: L Yogo w T Shocking Series A Shi Figure 4 FL 誂Keisumi (kg) Bad @ Do V Boar Zu 1 Mi Meal ・ 0.5 Figure 3 Cataly Trace Analysis @ ( kQ)

Claims (1)

[Claims] In a rough rolling method for long steel and wire rods that uses a rolling equipment that is a combination of an electric motor-driven horizontal rolling mill and a non-driven vertical rolling mill, the friction coefficient of the roll surface of the driven horizontal rolling mill is increased and the non-driven A rough rolling method for long steel and wire rods that reduces the coefficient of friction on the roll surface of a vertical rolling mill.