JPH0533281B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of heat treating materials to be heated in parallel in a continuous heating furnace such as a walking beam heating furnace, and particularly to a method for heat treating materials to be heated in parallel. The present invention relates to a method for preventing overheating of the edge of a heated material in a continuous heating furnace.

[Prior Art] A continuous heating furnace such as a walking beam heating furnace heats a slab (steel billet) produced by continuous casting or blooming to a predetermined temperature in order to roll it from a thick plate to a thin plate. It is desirable to heat the entire slab to a uniform temperature as much as possible.

A conventional continuous heating furnace will be explained with reference to FIGS. 7 to 10.

As shown in FIGS. 7 and 9, inside the heating furnace 1,
A fixed beam 4 and a movable beam 5 extending from the charging end 2 to the discharge end 3 of the heating furnace 1 are provided at appropriate intervals in the width direction of the heating furnace 1 by means of legs 4a and 5a. Although the moving beam 5 is not shown, its legs 5a extend from the bottom of the heating furnace 1 and are attached to a moving cart, and the moving beam 5 is moved upward, forward, and upward by the moving cart.
By lowering and moving backward, the material to be heated 6 supplied from the charging end 2 onto the fixed beam 4 and moving beam 5 is moved toward the discharge end 3 side. That is, the material to be heated 6 is supported by the moving beam 5 as the moving beam 5 rises, is moved by the advancement of the moving beam 5, and then the moving beam 5 is supported by the fixed beam 4.
As the material to be heated 6 descends further downwards, the material to be heated 6 reaches the fixed beam 4.
In this state, the moving beam 5 is moved backward, and then moved upward and forward, thereby sequentially moving the heated material 6 toward the delivery end 3 side. In this case, the materials to be heated 6 are charged in parallel as shown in FIG. 9, but the moving beams 5 for moving each of the materials to be heated 6 are moved on separate movable carts even if they are moved on the same movable cart. You may move by.

A plurality of burners 7 are provided in the heating furnace 1 to heat the material to be heated 6. For example, as shown in FIG. ₁ , a heating zone _L2 , and a soaking zone _L3 , the burners 7 are arranged so that the temperature distribution in the zone maintains a temperature distribution like the polygonal line indicated by a in the figure, as shown in Fig. 8. The material to be heated 6 is made to have a reference temperature curve as shown by b in the figure from the charging end 2 to the unloading end 3, and the heated material 6 is set to the target temperature T at the unloading end 3. There is.

[Problems to be Solved by the Invention] However, as shown in FIG. 9, both ends 6a, 6a of the parallel heated materials 6 are heated and become high. That is, as shown in FIG. 10, since there is heat input from each end surface, the temperature of the end portion 6a becomes higher than the center portion, and therefore, each temperature in the width direction of the parallel heated materials 6 in FIG. As shown by the distribution curve c, temperature unevenness occurs in the width direction. That is, the temperature curves at both ends 6a, 6a are higher than the reference temperature curve b, as shown by d in FIG.

On the other hand, the temperature of the portions that come into contact with the fixed beam 4 and the moving beam 5 tends to decrease, resulting in a temperature curve indicated by e in the figure. This cold spot has been improved in recent years by improving the fixed beam 4 and the moving beam 5, but the end 6a side has not been much of a problem until now, but it is necessary for improving the quality of the product. Normally, as shown in Figure 8, heating area L ₂ is set approximately 100°C higher than the target temperature T to improve the rising characteristics of the reference temperature curve b.
The reference temperature b at L ₃ is set 20 to 40°C higher than the target temperature T, but when the temperature inside the furnace in the heating area L ₂ is increased in this way, the end 6a of the heated material 6 becomes higher than the target temperature T. It gets worse and I don't like it. Therefore, if the temperature of this heating region _L2 is not raised above the target temperature T, the temperature rise at the end portion 6a can be suppressed, but the temperature rise of the entire heated material 6 becomes worse, and as a result, the target temperature T is not reached, which is undesirable.

[Object of the invention] The present invention has been made in consideration of the above circumstances, and
An object of the present invention is to provide a method for preventing overheating of the edges of a material to be heated in a continuous heating furnace, which can prevent overheating of both ends of the material to be heated in parallel in a continuous heating furnace.

[Summary of the invention] In order to achieve the above object, the present invention supplies plate-shaped materials to be heated in parallel on a moving beam and a fixed beam in a heating furnace, and raises, advances, and lowers the moving beam. - In a method of moving the parallel heated materials by moving them backwards and heat-treating them, the opposite ends of the parallel heated materials are brought close together and fed into the furnace, and the other of the parallel heated materials is supplied into the furnace. The material is moved with its ends insulated by a heat shield plate, and since the opposing ends of the parallel heated materials are placed close together, heat input from each end surface is blocked, and Since the other end is blocked from heat input by a heat shield plate, overheating of both ends is prevented and a uniform temperature distribution is achieved in the width direction of both heated materials.

[Embodiment] A preferred embodiment of the method for preventing overheating of the edge of a heated material in a continuous heating furnace according to the present invention will be described below with reference to the accompanying drawings.

Fig. 1 shows a cross section in the width direction of a continuous heating furnace such as a walking beam heating furnace. As explained in the conventional example shown in the figure, each of the beams 4 and 5 is connected to the charging end 2 of the heating furnace 1.
The plate-shaped material to be heated 6 is moved from the loading end 6 to the unloading end 3 by moving the moving beam 5 upward, forward, downward, and backward. The materials to be heated 6 supplied onto the moving beam 5 and the fixed beam 4 are charged in parallel so that their opposing ends 6a, 6a are close to each other, as shown in FIG.
In this case, the front and rear ends of the material to be heated 6 are also charged so as to be close to each other, but if the material to be heated 6 is a continuous long object in the furnace 1, it is charged as is. The other ends 6a, 6a of the parallel heated materials 6, 6 are connected to the heat shield plate 1.
1 prevents heat input from the end face. 1st
As shown in the figure, the heat shield plate 11 is connected by pins 10 to a support member 9 which is rotatably suspended from both sides of the upper part of the heating furnace 1 in the width direction thereof. This heat shield plate 11 has a heat insulating part 12 facing the heated material 6 side.
and a support frame portion 13 for supporting the heat insulating portion 12 thereof.
It consists of. Horizontal movement is provided on both sides of the heating furnace 1 to adjust the position of the heat shield plate 11 appropriately according to the width of the material to be heated 6 so that the heat shield plate 11 approaches the end portion 6a of the material to be heated 6. A device 14 is provided. This horizontal movement device 14 is supported on brackets 15 provided on both side walls of the heating furnace 1, and includes a cylinder 16 arranged so as to face in the width direction, and a cylinder 16 arranged to face the width direction.
6, and a connecting rod 18 connected to a pin 10 that passes through the side wall of the heating furnace 1 and connects the support member 9 and the heat shield plate 11, and the rod 17 of the cylinder 16 expands and contracts. By rotating the support member 9 in the width direction, the position of the heat shield plate 11 can be adjusted. As shown in FIG. 3, when the heated material 6 moves, the heat shield plate 11 moves from the position shown by the solid line (the position supported by the fixed beam 4) to the position shown by the two-dot chain line (the moving beam 5). Since it moves up and down between the raised position), it is formed to have a vertical length close to the end 6a in the range of vertical movement, and although not shown in the figure, for example, the heating Length of area L ₂ or heating area L ₂ and soaking area L ₃
It is formed to a certain length. The heat insulating material 12 of the heat shield plate 11 is made of a heat insulating material that can withstand high temperatures and is elastic, such as ceramic fiber or mineral fiber, and the supporting frame 13 is made of a ceramic molded product.

As described above, the materials to be heated 6 are fed and moved in parallel onto the fixed beam 4 and the movable beam 5 in the heating furnace 1, with the opposing ends 6a, 6a being close to each other. heated. In this case, since the opposing ends 6a of the heated material 6 are close to each other, heat input from there is blocked, thereby preventing overheating, and the other end 6a of the parallel heated material 6 Since the heat shield plates 11 are arranged close to each other,
Heat input from the end face is prevented, and overheating of the end portion 6a is prevented. In this case, the heat shield plate 11
If ceramic fiber, mineral fiber, or the like is used for the heat insulating material 12, the end 6a will not be damaged even if it hits the end 6a during movement.

Further, as explained in FIGS. 7 and 8, if the heat shield plate 11 is provided in the heating area _L2 where overheating is likely to occur, overheating can be prevented, but if it is also provided in the soaking area _L3 , it will be even more effective. can prevent overheating.

The material to be heated 6 that has been heat-treated and carried out from the heating furnace 1 is sent to a rolling process as appropriate and is rolled.
Since the end portion 6a of the material to be heated 6 is prevented from overheating, the temperature becomes uniform in the width direction, so that the accuracy of the plate thickness and plate width after rolling is improved, and the quality can be improved.

4 to 6 show other embodiments of the present invention, FIGS. 4 and 5 show an example in which the shape of the heat shield plate 11 is changed, and FIG. 6 shows an example in which the horizontal moving device 14 is changed. Give an example.

In FIG. 4, the heat shield plate 11 is formed to have an inverted L-shaped cross section,
The heat input from the upper surface side of the end portion 6a of the heated material 6 is controlled, and in FIG. It is designed to control the heat input from
This is appropriately adopted depending on the degree of overheating of the end portion 6a or depending on the heat convection within the heating furnace 1 to prevent overheating of the end portion 6a.

FIG. 6 shows another embodiment of the horizontal movement device 14 for adjusting the position of the heat shield plate 11. In the figure, the heat shield plate 11 is supported on a bracket 20 provided on the outer wall of the heating furnace 1 so as to be horizontally movable. and is supported by a horizontal rod 21 passing through its outer wall. The horizontal moving device 14 has its horizontal rod 21 and its horizontal rod 2.
The cylinder 22 is supported by a bracket 24 on the upper side wall of the heating furnace 1, and the upper end of the link lever 23 is rotatably connected to the bracket 24. The lower end is connected to the horizontal rod 21,
The middle part is connected to the rod 25 of the cylinder 22, and when the rod 25 expands and contracts, the link lever 2
3 rotates to horizontally move the horizontal rod 21 in the width direction to adjust the position of the heat shield plate 11. In the horizontal movement device 14 shown in FIG. 1, the heat shield plate 11 is suspended from the support member 9 and therefore moves slightly up and down during position adjustment, but in this embodiment, it moves horizontally and does not move up and down.

[Effects of the Invention] As is clear from the detailed description above, the present invention exhibits the following excellent effects.

(1) When the materials to be heated are charged in parallel into the heating furnace, by charging their opposing ends close together, heat input from the opposing ends can be blocked and overheating can be prevented. At the same time, the other end can be provided with a heat shield plate to prevent overheating of that end.

(2) Therefore, the temperature of the heat-treated material to be heated becomes uniform in its width direction, and when it is subsequently rolled, the accuracy of the plate thickness and plate width becomes better, and the quality can be improved.

(3) Since it is possible to prevent overheating of the end of the material to be heated, it is possible to raise the heating capacity significantly higher than the target temperature in the heating region, and the fuel consumption rate can be lowered accordingly, resulting in energy savings.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the method for preventing overheating of the edge of a heated material in a continuous heating furnace of the present invention, Fig. 2 is an enlarged view of the main part of Fig. 4 and 5 are sectional views showing other embodiments of FIG. 2, and FIG. 6 is a continuous heating furnace according to the present invention. Fig. 7 is a front sectional view of a continuous heating furnace, and Fig. 8 shows the temperature inside the continuous heating furnace of Fig. 7. Figure 9 is a diagram showing the temperature rise curve of the heated material. Figure 9 is a side sectional view of a conventional continuous heating furnace and a diagram showing the temperature distribution of the heated material in the furnace. Figure 10 is the temperature rise curve of the heated material in Figure 9. It is a figure explaining the heat input state of a material. In the figure, 1 is a heating furnace, 4 is a fixed beam, 5 is a moving beam, 6 is a heated material, and 11 is a heat shield plate.

Claims (1)

[Claims] 1. Supply plate-shaped materials to be heated in parallel on a moving beam and a fixed beam in a heating furnace, and move the moving beams upward, forward, downward, and backward to move and heat the parallel materials to be heated. The processing method is characterized in that the opposing ends of the parallel heated materials are brought into close proximity and fed into the furnace, and the other end of the parallel heated materials is insulated with a heat shield plate before being moved. A method for preventing overheating of the edge of a heated material in a continuous heating furnace.