JPH0797614A - Walking beam heating furnace - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent skid marks from being generated on the material to be heated by the walking beam heating method. [Structure] A walking beam for transporting a heated material charged into a furnace alternately toward a walking beam and a fixed beam supporting the heated material so that the heated material is conveyed toward an extraction port while being heated. A walking beam type heating furnace in which a walking beam 2 and a fixed beam 3 are composed of a plurality of beams meandering in the furnace width direction. [Effect] Since there is no variation in deformation resistance due to parts within the same material, the width and thickness of the product are uniform and the yield is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention inserts a long material to be heated such as a steel slab with its longitudinal direction aligned with the width direction of the heating furnace, and heats it while transferring it inside the furnace with a walking beam. A walking beam type heating furnace.

[0002]

2. Description of the Related Art When a long material such as a steel slab is hot-rolled, the material to be heated is charged into a continuous heating furnace, heated to a predetermined temperature, extracted, and rolled. This continuous heating furnace includes the following two types of furnaces. Pusher-type heating furnace A plurality of skid rails that hold the material to be heated are fixedly installed over the entire length of the furnace from the inlet to the outlet, and long materials are successively installed on the skid rail from the inlet. Push-in method.

Walking Beam Type Heating Furnace A fixed beam and a movable beam (walking beam) provided with skids on the upper part are alternately provided in the width direction of the furnace, and a walking beam and a walking beam are formed by using a cam. This is a system in which the support pillars on the support are raised and lowered together with the support, and the support is pulled by a hydraulic cylinder to place the material to be heated on the fixed beam.

Of the above heating furnaces, the pusher type heating furnace is
Since the material to be heated moves forward while sliding on the skid rail, flaws are likely to occur in the material to be heated. Therefore, a walking beam type heating furnace is generally used in many cases.

A walking beam of this walking beam type heating furnace is shown in a plan view of FIG. 4 (a) and FIG. 2 (b).
The walking beam 21 is supported by columns 25 connected to a plate-like support 24 arranged below the furnace bottom 23 of the furnace 22,
Both the walking beam 21 and the column 25 have an outer surface protected by a refractory so as to withstand a high temperature (1200 to 1300 ° C.) in the furnace, and a cooling water is allowed to pass through the pipe-shaped inner surface.

The walking beam 21, the support 24, and the support 25 are used as a reduction gear 27 of a drive device 26.
When the drive shaft 28 is rotated by, the cam 29 fixed to the drive shaft 28 ascends to lift the heated material 31 on the fixed beam 30. With the walking beam 21 lifting the material 31 to be heated, the support 24 is pulled by a hydraulic cylinder (not shown), and the material 31 to be heated is advanced.

When the cam 29 further rotates from this state, the walking beam 21, the support 24 and the support 2
5 descends and the heated material 31 on the walking beam 21
Is again lowered onto the fixed beam 30. The material to be heated in the furnace advances while being heated while repeating such operations. The fixed beam 30 is used for the bottom 23 of the heating furnace 22.
It is supported by a column 32 provided on the.

In the walking beam type heating furnace,
When the heated material 31 is supported by the walking beam 21 and moves forward, the heated material 31 is moved by the walking beam 2
Since 1 is water-cooled, there is a temperature difference between the part of the walking beam 21 that hits the skid and the part that does not hit the skid. This temperature difference appears as a difference in deformation resistance during hot rolling and causes variations in thickness and width of the hot rolled steel strip or the like obtained by rolling.

In order to prevent the occurrence of such a temperature difference due to the portion of the material to be heated, conventionally, a plurality of walking beams 21 are spaced apart from each other, or the walking beams 21 are provided at the middle portion in the longitudinal direction of the furnace in the width direction of the furnace. To change the position where the skid hits, or by providing a skid button on the skid, and devising the shape, height, and quantity of the skid to minimize the temperature difference between the part that hits the skid and the part that does not hit the heated material. However, there is a limit due to the shape of the heating material and the position of the heating furnace inside.

On the other hand, in the technique disclosed in Japanese Unexamined Patent Publication No. 52-46310, as shown in FIG. 5, the walking beam 41 is formed in a meandering shape in the longitudinal direction of the heating furnace 22 to form a skid. The contact position is dispersed in the longitudinal direction of the material to be heated to reduce the temperature difference. In this case, the fixed beam 32 is linear as in the conventional case.

[0011]

However, in the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 52-46310, even if the walking beam is made to meander in the longitudinal direction of the heating furnace, the number of columns supporting the beam is required. There is a problem that a large amount of meandering cannot be obtained due to the relationship with the driving device for the walking beam on the furnace bottom and the temperature difference inside the material to be heated cannot be sufficiently reduced.

The present invention has been made in order to solve the above-mentioned problems of the prior art. Since the walking beam is meandered in the width direction of the heating furnace, a large amount of meandering can be taken and therefore skids can be hit. It is an object of the present invention to provide a walking beam type heating furnace in which parts can be largely dispersed in the longitudinal direction of the material to be heated, and as a result, the temperature difference inside the material to be heated can be sufficiently reduced.

[0013]

In the walking beam type heating furnace according to the present invention, the steel pieces charged in the furnace are alternately placed on the walking beam and the fixed beam for supporting the steel piece. In a walking beam type heating furnace in which a piece is heated and conveyed toward an extraction port, a walking beam and a fixed beam are constituted by a plurality of beams meandering in the furnace width direction.

[0014]

The skid of the walking beam type heating furnace according to the present invention has a large inclination angle with respect to the width direction of the material to be heated, whereas the conventional skid faces the width direction of the material to be heated. It is inclined. Therefore, since the part of the skid that hits the heated material is dispersed in the longitudinal direction of the heated material, the temperature difference between the cross sections in the width direction along the rolling direction of the heated material becomes small, and the difference in deformation resistance in the width direction becomes small. Is unlikely to occur over the entire length of the heated material. As a result, the variation error of width and thickness within the same product is 30%
The degree can be reduced.

[0015]

EXAMPLE A walking beam type heating furnace according to an example of the present invention will be described with reference to FIG. 1A is a plan view of the heating furnace, FIG. 1B is a cross-sectional view of the heating furnace, and FIG.
(C) is a perspective view showing a walking beam portion of the heating furnace.

The walking beam and the fixed beam of the heating furnace 1 have a plurality of walking beams 2 whose plane shape is bent in a mountain shape in the traveling direction of the material 31 to be heated.
And a fixed beam 3. Each walking beam 2 is supported by a pillar 6 connected to a plate-shaped support 5 arranged below the furnace bottom 4 of the furnace 1, and both the walking beam 2 and the pillar 6 have a high temperature in the furnace ( The outer surface is protected by a refractory so as to withstand 1200 to 1300 ° C.), and the cooling water is passed through the pipe-shaped inner surface.

These walking beams 2 and supports 5
When the drive shaft 9 is rotated by the speed reducer 8 of the drive drive device 7, the column 6 and the cam 10 are fixed to the drive shaft 9.
And the heated material 31 on the fixed beam 3 is lifted. While the walking beam 21 is lifting the heated material 31, the support 5 is pulled by a hydraulic cylinder (not shown) to move the heated material 31 forward.

When the cam 10 further rotates from this state, the walking beam 2, the support 5 and the column 6 descend, and the material 31 to be heated on the walking beam 2 is lowered onto the fixed beam 3 again. The material 31 to be heated in the furnace advances while being heated while repeating such operations.
The fixed beam 3 is supported by columns 11 provided on the bottom 4 of the heating furnace 1.

FIG. 2 is a side view showing the driving device 7 for the walking beam 2. Below the supporting body 5 supporting the walking beam 2 and the support column 6, there is provided a cam 10 which rotates with the rotation of the pinion 13 and the gear 14 driven by the electric motor 12 to move the supporting body 5 up and down. A hydraulic cylinder 15 is connected to the side surface of the body 5 to pull the support 5 and advance the heated material 31.

Then, the cam 10 rotates to rotate the material 31 to be heated.
When the moving beam 2 is lifted above the fixed beam 3 by the walking beam 2, the support 5 is pulled by the hydraulic cylinder 15 and the heated material 31 advances. Further, when the cam 10 rotates, the support 5 descends and the walking beam 2 also descends.
When is below the fixed beam 3, the material 31 to be heated is placed on the fixed beam 3. The material 31 to be heated advances while repeating such operations.

FIG. 3 is a plan view showing skid marks of a walking beam generated on the surface of the long heated material 31. FIG. 3A shows the skid mark 16a when heated by the walking beam type heating furnace of the present invention.
(B) shows a skid mark 16b when heated in a conventional general walking beam type heating furnace. In this example, one fixed beam can be passed by advancing the material to be heated with the walking beam five times. Skid marks 16a and 1
In 6b, the order of occurrence is from to numerical order.

The contact portion 16b when heated in the conventional walking beam type heating furnace indicates the direction (width direction) orthogonal to the rolling direction of the long material 31 to be heated, so that the contact portion 16b is long. It does not move in the longitudinal direction of the heating material 31, but only in a limited specific position in the longitudinal direction, and the contact portion 16b occurs only in the width direction of that position. Therefore, the heat-affected zone is generated only at a specific position in the longitudinal direction of the long heated material 31, the width and thickness of the final product are varied, and the yield of the product is reduced.

On the other hand, the skid mark 16a when heated by the walking beam type heating furnace of the present invention is
Since the long material 31 to be heated is inclined by θ degrees with respect to the direction (width direction) orthogonal to the rolling direction, it extends in the longitudinal direction of the material 31 to be heated. In addition, the contact portion 16
a moves in the longitudinal direction of the material to be heated 31. Therefore,
The heat effect of the skid mark 16a appears almost evenly in the entire longitudinal direction of the material 31 to be heated, there is no part where the temperature locally drops, and rolling is performed without changing the deformation resistance. There is no variation in width and thickness, and the product yield is improved.

The horizontal movement distance (p) of each walking beam is set to be smaller than the pitch in the furnace length direction in which the walking beam is installed. It is extremely unlikely that the position of the skid mark will overlap.

In the description of the embodiments of the present invention, the plane shape of the walking beam has been described as a mountain shape, but it is not limited to the mountain shape, and may be a W shape or a more meandering shape.

[0026]

According to the present invention, the product yield is improved.

[Brief description of drawings]

FIG. 1 (a) of a walking beam type heating furnace of the present invention
Is a plan view, (b) is a cross-sectional view, and (c) is a perspective view showing a walking beam portion of a heating furnace.

FIG. 2 is a side view showing a driving device for a walking beam.

3A and 3B are plan views showing a situation where a skid mark is generated, FIG. 3A being the case of the present invention, and FIG. 3B being the conventional case.

4A is a plan view and FIG. 4B is a cross-sectional view of a conventional walking beam type heating furnace.

FIG. 5 is a plan view of another conventional walking beam type heating furnace.

[Explanation of symbols]

 1 Heating Furnace 2 Walking Beam 3 Fixed Beam 4 Hearth 5 Support 6 Support 7 Drive Drive 8 Reducer 9 Drive Shaft 10 Cam 11 Support 12 Electric Motor 13 Pinion 14 Gear 15 Hydraulic Cylinder 16a Skid Mark 16b Skid Mark

Claims (1)

[Claims] 1. The material to be heated loaded into the furnace is alternately placed on a walking beam and a fixed beam for supporting the material to be heated so that the material to be heated is conveyed toward an extraction port while being heated. In the walking beam type heating furnace, the walking beam and the fixed beam are constituted by a plurality of beams meandering in the width direction of the furnace.