JPH06218405A - Device for heating end part of intermediate rolled stock - Google Patents

Abstract

PURPOSE:To obtain a product having mechanical characteristic values in the width direction by providing plural driving rolls which are arranged up and down in zigzag on a leveler device and an inlet-side conducting guide. CONSTITUTION:The end parts of an intermediate rolled stock are heated with an end part heating device between a roughing mill 10 and a finishing mill 18 of a hot rolling line. The end part heating device is provided between a side guide 1 and an inlet guide 5 for a flying crop shear and is composed of the inlet-side conducting guide 2, leveler device 3 and induction heating device 4 which is provided with six profiling rollers 17 for heating the end parts. The leveler device 3 is formed using five driving rolls which are arranged up and down in zigzag on both sides of the pass line of the intermediate rolled stock and the inlet-side conducting guide 2 for inducing the top part of the intermediate rolled stock to the leveler device 3. In this way, temp. drop in the end parts of the intermediate rolled stock is compensated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a device for correcting the shape of an intermediate rolled material used in a hot rolling process.
The present invention relates to an end heating device that compensates for a temperature drop at the end of an intermediate rolled material.

[0002]

2. Description of the Related Art When a metal material is hot-rolled, the metal material is transferred on a line and gradually cooled while undergoing processing. In particular, the temperature drop at the widthwise end portion (edge portion) Is remarkable, and as a result, the material of that portion is deteriorated and cracks are likely to occur.

In order to prevent the temperature drop at the end portion in the width direction, the end of an intermediate rolled material (generally referred to as a rough bar material or a rough rolled material) is provided between the rough rolling mill and the finish rolling mill. An end heating device is provided to heat the section to compensate for the temperature drop. However, in the intermediate rolled material processed by the rough rolling mill,
Usually, nose bending (warping) occurs in the top (tip) part and bottom (rear end) part, and waviness occurs in the middle part, so it is not possible to properly heat the end part as it is, Various measures are taken against this.

For example, in Japanese Unexamined Patent Publication No. 2-15814, in order to flatten a bent portion of a metal plate by correcting vertical deformation of the metal plate in a transfer line on the upper side of an end heating device for the metal plate. An end heating device provided with a pressing roller device has been proposed.

FIG. 5 is a schematic sectional view showing the structure of this apparatus. After rolling by rough rolling mill 10, table roller 14
In the intermediate rolled material 9 transferred by, the nose bend generation portions of the top portion and the bottom portion are held by the presser roller device 11
It is sandwiched from above and below by a fixed guide 19 and one press roll 13, is straightened while passing through this device 11, the end is heated by an end heating device 12, and then transferred to a finish rolling machine 18. .

The inventor of the present invention, in Japanese Patent Application No. 3-230377, discloses an induction heating apparatus for heating the vicinity of an end portion of an intermediate rolled material passing on a hot rolling line, in which the top portion and the bottom portion of the intermediate rolled material are heated. An end heating device capable of uniformly heating the upper and lower surfaces near the end of the intermediate rolled material by keeping the gap between the lower surface of the upper induction heating coil and the surface of the intermediate rolled material constant according to the nose bend amount. showed that.

FIG. 6 is a schematic sectional view showing the structure of this apparatus. As shown in the figure, this device is located between the rough rolling mill 10 and the finish rolling mill 18, and has a pressing roller device 11 for flattening the nose bend portion of the intermediate rolled material 9 and this pressing roller device.
It comprises an induction heating device 4 for heating the end portion of the intermediate rolled material 9 transferred from 11, and is provided with two sets of induction heating coils 16 facing each other with a certain gap as a heating means. The presser roller device 11 is arranged at the upper part and can be raised and lowered.
The intermediate rolling material 9 is constrained by three rollers, namely, a press roll 13 for the book, a table roller 14a arranged at the lower part, and a non-driving intermediate roller 15 mounted between the table rollers 14a and 14b. It is a three-point restraint type that straightens. On the entry side of the intermediate rolled material 9 of the induction heating device 4, it is possible to move up and down in order to keep the gap d between the upper surface of the intermediate rolled material 12 and the lower surface of the induction heating coil 16 above the induction heating device 4 constant. A follower roller 17 is provided.

[0008]

In the end heating device proposed in Japanese Patent Laid-Open No. 15815/1990, the nose bends at the top and bottom of the intermediate rolled material 9 are corrected as shown in FIG. In order to do this, a rotatable presser roll 13 and a fixed guide 19 are used, but when pressed by the force of the presser roll 13 from above, the back surface of the intermediate rolled material 9 is rubbed by the fixed guide 19 and the intermediate Scratch marks and seizure marks occur on the rolled material 9. In particular, this kind of flaw appears remarkably in stainless steel with little scale formation.

In the end heating device of FIG. 6 shown in Japanese Patent Application No. 3-230377, since the intermediate roller 15 is a non-driving roll, a roll peripheral speed between the table rollers 14a and 14b, which is a driving roll, is kept. Variation occurs, and the correction function of the three-point restraint type presser roller device 11 does not work well. Further, in the case of the straightening device of the three-point constraint type in which the leveling is performed only by one pressing roller 13 from the above, only the downward bending action cannot be obtained and the sufficient flattening effect cannot be obtained.

Further, in any of the above devices, when the pressing-down timing of the presser roll 13 from the upper side is not good and the descending time is fast, the top part of the intermediate rolled material 9 having a nose bend is good at the roll gap. Does not enter Therefore, a state of being struck (bending of the tip) occurs, and the pressing roller device 11 is damaged. Therefore, the pressing roller device 11 can be applied only to the middle to bottom portions of the intermediate rolled material 9.

The present invention solves the above problems and compensates for the temperature drop at the end of the intermediate rolled material, which can correct the shape of the intermediate rolled material, including the nose bend at the top and bottom. An object is to provide an end heating device.

[0012]

The summary of the present invention is as follows.
It is in the end heating device of (1) and (2).

(1) A device for heating an end portion of an intermediate rolled material between a rough rolling machine and a finish rolling machine of a hot rolling line, which apparatus straightens the intermediate rolled material before heating the end portion. There is a leveler device for this, and this leveler device introduces five drive rolls arranged in a zigzag pattern up and down across the pass line of the intermediate rolled material and the top guide of the intermediate rolled material into the leveler device. An end heating device comprising:

(2) As the above-mentioned end heating device, an induction heating device having a follower roller for keeping a gap between the lower surface of the upper induction heating coil and the upper surface of the intermediate rolled material constant is provided. The end heating device of (1) above.

FIG. 1 is a plan view showing an example of a rolling line incorporating the end heating device of the present invention. This end heating device is provided between the exit side guide 1 and the frying crop shear inlet guide 5 of the known rough rolling mill 10,
It is composed of an entrance side guide 2, a leveler device 3 and an induction heating device 4 equipped with six follower rollers 17 for heating the ends. In FIG. 1, 6 is a flying crop shear, and 18 is a finish rolling mill.

FIG. 2 is a diagram showing an example of the leveler device 3, FIG. 2 (a) is a front view, and FIG. 2 (b) is a side view. Figure 3
FIG. 3 is a schematic vertical sectional view of the leveler device 3. 2 and 3
As shown in FIG. 3, the leveler device 3 is composed of two upper rollers 8a, three lower rollers 8b, an entrance guide 2 and a lowering device 7 for the upper roller 8a.
It has a function of restraining and straightening the intermediate rolled material 9 at five points by using a total of five rollers. Further, the leveler device 3 can drive two upper rollers 8a and three lower rollers 8b.

The entry side guide 2 is provided on the entry side of the leveler device 3 so that the intermediate rolled material 9 can smoothly enter between these upper and lower rollers.
Since the intermediate rolled material 9 in which the nose is bent is often transferred and hit, it must be made strong.

[0018]

If the leveler device 3 shown in FIGS. 2 and 3 is used,
After the nose bends at the top and bottom of the intermediate rolled material 9 transferred through the rough rolling mill 10 and the corrugated parts at the middle portion are straightened by the rollers 8a and 8b, they can be transferred to the induction heating device. Further, as shown in FIG. 1, the induction heating device is provided with a follower roller 17, so that the end portion of the intermediate rolled material 9 is made uniform from the top portion to the bottom portion while adjusting the gap. It can be heated efficiently.

That is, as shown in FIG. 3, since the entrance-side guide guide 2 is provided along the two upper rollers 8a of the leveler device 3 up to the immediate vicinity of the leveler device 3,
Even if there is upward nose bending (hereinafter referred to as "nose lift") at the top part of the intermediate rolled material 9, the entrance side guide guide 2 makes it smooth in the gap between the two upper rollers 8a and the three lower rollers 8b. Can be guided to.

Since the upper roller 8a is provided with the rolling down device 7, the gap between the upper roller 8a and the lower roller 8b is controlled by elevating and lowering the upper roller 8a so that the intermediate rolled material 9 is leveled. Three
It is also possible to insert it to a desired position inside.

Two upper rollers 8a and a lower roller 8a
The reason for setting b to 3 and a 5-point constraint formula is as follows.
That is, as described above, in the case of the three-point restraint type straightening device shown in FIG. 6, only the downward bending action cannot be obtained and the sufficient flattening effect cannot be obtained, whereas in the case of the five-point restraint type, This is because it is possible to apply a bending action in both the upper and lower directions, and it is possible to secure accurate flatness without variations.

The intermediate rolled material 9 inserted to a desired position in the leveler device 3 is constrained at five points by two upper rollers 8a and three lower rollers 8b, and the nose bend generated at that portion is suppressed. Leveling is corrected. At this time,
Since the upper roller 8a and the lower roller 8b are all drive rolls, it is possible to eliminate variations in the peripheral speed between the rolls, and the rollers 8a and 8b in the leveler device 3 can be eliminated.
And rubbing with the intermediate rolled material 9 is eliminated. As a result, no scratches or seizures occur on the surface of the intermediate rolled material 9. This desired intermediate rolled material 9 which has been subjected to favorable leveling correction can be transferred to the induction heating device 4 equipped with the follower roller 17, so that appropriate end heating can be performed over the entire length, and the quality of the end can be improved. A product without deterioration can be obtained.

[0023]

[Example] Hot rolling was performed on ordinary steel to obtain a width of 929
1 to 3 of the present invention having the structure shown in FIGS. 1 to 3 for correcting and heating the end portion and the middle portion of the intermediate rolled material when manufacturing a product having a width of 929 mm and a thickness of 1.6 mm from the intermediate rolled material having a thickness of mm and a thickness of 37 mm. Was performed by using an end heating device.

The length of each roll of the leveler device is 1800 mm,
The diameter was 350 mm, and the distance L between the rolls was fixed at 457.5 mm for both the upper and lower rollers. The radius of curvature R of the entrance guide is about 1500 mm, and the distance D between the lower end of the entrance guide and the pass line is 60 mm.

An example of the present invention is one in which proper straightening and heating can be performed through the leveler device described above, and a comparative example is one which is not included in the above leveler device and is therefore heated without correction in an unsuitable large gap condition. And

FIG. 4 shows an example of the grain loss ratio and the mechanical characteristic values in the width direction of the finished product which is obtained by finish-rolling by setting the heating temperature of the intermediate rolled material to 1200 ° C. In FIG.
The black circles are the examples of the present invention, and the white circles are the comparative examples. Hatching means that the two overlap.

As is apparent from FIG. 4, in the example of the present invention in which proper correction and heating are performed, stable mechanical characteristic values can be obtained in the width direction. On the other hand, in the comparative example in which heating is performed without straightening, deterioration of mechanical property values at both ends is recognized.

[0028]

According to the edge heating device for an intermediate rolled material of the present invention, a product having stable mechanical property values in the width direction can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a rolling line incorporating an end heating device of the present invention.

FIG. 2 is a view showing an example of a leveler device in the end heating device of the present invention, (a) is a front view and (b) is a side view.

FIG. 3 is a schematic vertical cross-sectional view of a leveler device.

FIG. 4 is a diagram showing an example of a grain loss rate and a mechanical characteristic value in a width direction of a product when the end heating device of the present invention is used.

FIG. 5 is a schematic vertical cross-sectional view showing an example of the configuration of a conventional end heating device.

FIG. 6 is a schematic vertical cross-sectional view showing another example of the configuration of the conventional end heating device.

[Explanation of symbols]

1: Side guide, 2: Entrance guide, 3: Leveler device, 4: Induction heating device, 5: Flying crop shear inlet guide, 6: Flying crop shear,
7: Rolling down device for the upper roller 8a, 8a: Upper roller,
8b: lower roller, 9: intermediate rolled material, 10: rough rolling mill, 1
1: Presser roller device, 12: End heating device, 13: Presser rolls, 14, 14a, 14b: Table roller, 15: Intermediate roller, 16: Induction heating coil, 17: Tracing roller, 1
8: Finishing mill, 19: Fixed guide, d: Gap, D:
The distance between the lower part of the tip of the entrance guide 2 and the pass line,
L: Distance between rolls of leveler device, R: Radius of curvature of entrance side guide 2

Claims (2)

[Claims] 1. A device for heating an end portion of an intermediate rolled material between a rough rolling machine and a finish rolling machine of a hot rolling line, the apparatus straightening the intermediate rolled material before heating the end portion. It has a leveler device, and this leveler device has five drive rolls arranged in a zigzag pattern on the upper and lower sides of the pass line of the intermediate rolled material and an entrance side guide guide for introducing the top part of the intermediate rolled material into the leveler device. An end heating device comprising: 2. An induction heating device having a tracing roller for keeping a gap between the lower surface of the upper induction heating coil and the upper surface of the intermediate rolled material constant as the end heating device. Item 1. The end heating device according to item 1.