JPH09295165A - Method and equipment for joining hot-rolled steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an equipment for joining hot-rolled steel members in which the whole equipment is miniaturized and light in weight, the operation of each component in the equipment is reduced and simple, the elevating/lowering stroke of a die is reduced, the time required for the welding with pressure can be reduced, and firmer welded strength is obtained by using a cut piece because the reducing flame of a reducing flame burner is guarded with the cut piece and becomes stable. SOLUTION: In welding with pressure a back side of a rear end part of a preceding steel member to a surface of a forward end part of a succeeding steel member 6, the scale on the pressure-welded surface of the steel member is removed by drawing cut pieces 11, 12 and the steel member is cut as necessary with the preceding steel member 1 set to an upper die 5 of the press and with the succeeding steel member 6 to a lower die 7 of the press, and with each pressure-welded part in either of the normal atmosphere, the reducing atmosphere or the non-oxidizing atmosphere. The cut pieces 11, 12 are pressure- welded under the same condition as the drawing thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for joining hot steel products by combining a cutting device and a hydraulic press in a continuous hot rolling line for steel products.

[0002]

2. Description of the Related Art In a steel manufacturing plant, continuous processes are energetically promoted for the purpose of energy saving, improvement of product yield, and improvement of productivity. Among them, continuous hot rolling for producing hot rolled steel sheet is one of the important issues.

By the way, in the conventional hot-rolled steel sheet, the heated slabs are supplied to the rough rolling machine and the finish rolling machine one by one to perform rolling intermittently. However, in such intermittent rolling, not only is it inefficient in itself,
In particular, when the material to be rolled has a small plate thickness, its tip is often deformed and hits a guide roll, and the trailing end is often narrowed when it leaves the rolling mill to damage the rolling roll. When these troubles occur, it is inevitable to stop the rolling line and perform repairs or roll replacement. To prevent such troubles, the rolling speed must be slowed down,
The rolling efficiency is further reduced.

Further, at the leading end and the trailing end of the hot rolled steel sheet, the rolling speed is out of balance as compared with the central portion, and the hot rolling steel sheet is out of the appropriate rolling temperature range. further,
At the tip of the hot-rolled steel sheet, the central portion in the strip width direction projects in the rolling direction to narrow the strip width, and at the rear end, a phenomenon called a fish tail in which the strip width center portion is recessed occurs. In addition, there is also a problem that the strip width is narrowed due to a sharp increase in tension when the tip is caught in the rolling roll or when starting winding on the down coiler. As described above, since the leading end and the trailing end of the steel sheet after finish rolling become defective parts as products, those parts must be cut off, resulting in a large decrease in production yield.

In order to solve the above problems,
In recent years, a preceding rough-rolled steel sheet (hereinafter referred to as "preceding steel material") and a subsequent rough-rolled steel sheet (hereinafter referred to as "trailing steel material") are joined between a rough rolling mill and a finish rolling mill. However, a method of continuously performing finish rolling has been proposed.
In this case, joining is most practically performed by stacking the ends of the steel material from which scale has been removed (descaled) and pressing them together.

[0006] As this method, the end portions of the hot steel materials are overlapped with each other in a reducing flame atmosphere due to a direct flame, or they are butted against each other, and a rotary cutting tool is used in the same reducing flame atmosphere before the pressure welding. One of the applicants of the present invention has proposed a method of performing descaling in JP-A-6-335785.

The method of joining hot steel materials proposed in JP-A-6-335785 will be described below with reference to FIG. The preceding steel material 1 sent on the transport table is stopped when the rear end thereof reaches a predetermined position and clamped by the clamp device 2 (see the imaginary line in FIG. 7). After that, the preceding steel material 1
The table roller 3 and the reducing flame burner 4 are both raised to a predetermined position, and the upper die 5 of the press is brought into contact with the rear end of the preceding steel material 1 (see the solid line in FIG. 7). Next, the trailing steel material 6 sent on the carrying table is fixed at a position where its tip end overlaps the rear end portion of the raised preceding steel material 1 at a constant interval, that is, a lower mold fixed at a fixed position. It is stopped when it comes to 7, and clamped by the clamp device 8.

In the above state, the rotary cutting tool 9 is inserted between the preceding steel material 1 and the following steel material 6, and the trailing end of the preceding steel material 1 is placed in the reducing flame atmosphere of the reducing flame burners 4 and 10 which have been ignited in advance. The back side of the part and the front side of the front end of the trailing steel material 6 are cut to perform descaling. After the descaling is completed, the rotary cutting tool 9 is taken out, the upper die 5 is lowered, and the upper and lower dies 5 and 7 are used to reduce the rear end portion of the preceding steel material 1 and the leading end portion of the following steel material 6 in a reducing flame atmosphere. After pressing, the reducing flame burners 4 and 10 are extinguished.

The above work is carried out during finish rolling.
That is, since it is performed while moving the joining device together with the steel material while the steel material is being conveyed at 60 m / min,
It is necessary to complete the pressure welding in the shortest possible time. When the pressure welding is completed, the welding device retracts to the work start position and waits until the next steel material is welded.

When the upper die 5 descends, the table roller 3 descends simultaneously with the upper die 5. Further, before the rear end of the preceding steel material 1 and the front end of the following steel material 6 are pressure-contacted by the upper and lower molds 5, 7, or when the pressure contact is started, the clamp device 2, 8 releases the clamp, Coping with prolongation.

[0011]

However, in the invention proposed in Japanese Unexamined Patent Publication No. 6-335785, a rotary cutting tool having a large diameter is inserted into and taken out from the steel material, so that a large space is required and the steel material of the preceding steel material is required. The lifting stroke is long and takes time. Also, since the rotary cutting tool is rotating at high speed, the reducing flame of the reducing flame burner covering the cutting surface of the steel material after cutting may be disturbed and the reducing flame may break, and a stable joining state There is also the problem that you cannot get it.

The present invention has been made in view of the above-mentioned conventional problems, and a method for joining by performing descaling or cutting as necessary without using a rotary cutting tool that causes a problem, and The purpose is to provide a device.

[0013]

In order to achieve the above-mentioned object, the present invention provides a prior heat set in a die of a press under any of a normal atmosphere, a reducing atmosphere and a non-oxidizing atmosphere. Remove the scale of the pressure contact surface between the rear surface of the rear end of the steel plate and the surface of the front end of the subsequent hot steel set in the lower mold of the press by pulling out the metal cutting material,
If necessary, the steel material will be cut, and then pressure welding will be performed under the same conditions as for the drawing of the cutting metal. And
By using such a cutting hardware, the up-and-down stroke of the preceding steel material and the up-and-down stroke of the press machine can be shortened, and the working time can be shortened. Further, the reducing flame of the reducing flame burner is not disturbed, and a stable joining state can be obtained.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The hot steel joining apparatus of the present invention comprises:
Clamping the rear end of the preceding hot steel material, for example, a clamping device provided with a clamping jig at each rod end of a pair of cylinder devices that are arranged opposite to each other with the front and back surfaces of the preceding hot steel material sandwiched therebetween, A clamping device having the same configuration as described above, which clamps the leading end of the trailing hot steel material, an elevating device that elevates the clamped preceding hot steel material by a predetermined amount, and vertical movement by these clamping devices and elevating devices. Cutting hardware for scale removal arranged to be opposed to the pressure contact surface of the hot steel material held in parallel in a stepwise manner, and pulling out this cutting hardware, for example, a hydraulic cylinder device, and pulling cutting by these devices In order to make the range of operation a reducing flame burner device that creates a reducing atmosphere as necessary, or a non-oxidizing atmosphere if necessary, for example, in the upper and lower molds of a pressing device described later. The attached shield cover and non-oxidizing gas pipes communicating with this shield cover, the rear surface or the rear surface of the front end of the preceding hot steel material after the drawing cutting, and the front surface or the rear surface of the subsequent hot steel material. It is equipped with a press device for press contact.

The hot steel joining method of the present invention is carried out by using the hot steel joining apparatus of the present invention described above. When pressing the front surface or the back surface of the front end of the hot steel, the preceding hot steel is set in the upper die or the lower die of the press, and the subsequent hot steel is the lower die of the press. Or, with the upper mold set, the pressure contact surface of each can be removed under normal atmosphere, reducing atmosphere or non-oxidizing atmosphere by removing the scale of the steel material pressure contact surface by pulling out the cutting metal object and steel material if necessary. Cutting, and then under the same conditions as the above-mentioned drawing of the metal piece, that is, in a normal atmosphere,
The pressure is applied in either a reducing atmosphere or a non-oxidizing atmosphere.

By the way, in the cutting hardware and its withdrawal, two cutting hardware with a cutting tool attached only to the front surface side,
It may be upside down and the back side may be pulled out in the opposite direction at the same time from the overlapped state, but by pulling the cutting hardware with the bite attached to both the front and back sides in one direction, the front and back sides of steel materials held in parallel The method of cutting is also effective.

The drawing of the cutting metal fittings with the cutting tools on both the front and back surfaces can be carried out by arranging the cutting metal fitting at a right angle in the horizontal direction with respect to the traveling direction of the hot steel and pulling it out at a right angle in the horizontal direction relative to the roller table. good. When it is pulled out in this direction, the press contact surface can be processed horizontally, which has the advantage that the processing allowance is small.

According to the present invention described above, since the holding interval of the hot steel material can be reduced as compared with the case where the conventional rotary cutting tool is used, the vertical distance of the press device can be shortened and the pressure welding time can be shortened. It is very effective for the present invention carried out during continuous rolling of hot steel. Also for the reducing flame burner device, since it is used where it is sandwiched between the hot steel material and the cutting hardware, the cutting surface can be sufficiently covered with the reducing flame and stable joining can be performed.

[0019]

EXAMPLE A case of carrying out the hot steel joining method according to the present invention will be described below using the hot steel joining apparatus of the present invention shown in FIGS. here,
A case where the rear surface of the rear end portion of the preceding hot steel material and the front surface of the front end portion of the subsequent hot steel material are pressed together will be described. FIG. 1 is a schematic explanatory view showing a first embodiment of a hot steel joining apparatus of the present invention, FIG. 2 is a schematic explanatory view showing a second embodiment of a hot steel joining apparatus of the present invention, and FIG. 3 is a schematic explanatory view showing a third embodiment of the hot steel joining apparatus of the present invention, FIG. 4 is an explanatory view of essential parts of a fourth embodiment of the hot steel joining apparatus of the present invention, and FIGS. In the drawings showing an example of the cutting hardware used in the embodiment shown in,
(A) is a side view, (b) is an enlarged view of the tool attachment part,
FIG. 6 is a plan view similar to that of FIG. 1 to 6, the same numbers as those in FIG. 7 indicate the same or corresponding portions, and detailed description thereof will be omitted.

In FIGS. 1 and 2, 11 is a preceding steel material 1.
A metal fitting for cutting the pressure contact surface on the rear surface of the trailing end portion, and 12 a metal fitting for cutting the pressure contact surface on the front surface of the trailing steel material 6 respectively covering the entire width direction of the preceding steel material 1 and the following steel material 6. As shown in FIG. 5, the pressure contact portion of the steel material can be cut with a uniform load on the back surface of the trailing end portion of the preceding steel material 1 and the surface of the trailing steel material 6 facing the front surface of the leading end portion. , 6 so that the line connecting the cuts has slight taper 11b, 12b,
Many a and 12a are attached. The cutting hardware 11 and 12 replaces the conventional rotary cutting tool.

Among them, in the first embodiment shown in FIG. 1, while the pressure contact surface is covered with a reducing flame atmosphere obtained by igniting the reducing flame burners 4 and 10, the back surface side is polymerized, and the cutting metal article is polymerized. Although not shown in the drawings, 11 and 12 are simultaneously pulled out in diagonally opposite left and right directions in FIG. 1 by using a pulling device using, for example, a hydraulic cylinder device or a rack and pinion mechanism to maintain the interval for cutting the steel material ( While maintaining the processing dimensions), the surface of the steel material is descaled or cut at a stretch.

In the first embodiment shown in FIG. 1, the reducing flame burners 4 and 10 are the preceding steel 1 or the following steel 6 and the cutting metal 1
Since the reducing flame is not disturbed even during the cutting work with the cutting hardware 11 and 12, it is possible to maintain a stable reducing flame atmosphere and to obtain a reliable joint surface. Like

In the second embodiment shown in FIG. 2, the upper and lower dies 5 and 7 of the press machine are covered with the shielding covers 13 and 1, respectively.
4 is installed and communicates with these shielding covers 13 and 14,
The non-oxidizing gas pipes 15 and 16 such as N ₂ and CO ₂ are supplied into the shielding covers 13 and 14 to supply the N ₂ gas, for example, in a non-oxidizing gas atmosphere to form the cutting metal parts 11 and 12. ,
Using a drawing device (not shown) similar to that of the embodiment shown in FIG. 1, they are simultaneously drawn in diagonally opposite left and right directions in FIG. 2, and the rear end rear surface of the preceding steel material 1 and the front end surface of the following steel material 6 are cut into metal pieces. Descale at 11 and 12 at a stretch,
Or cut.

FIG. 3 shows a third embodiment of the hot steel joining apparatus of the present invention.
The cutting hardware 17 used in this third embodiment is different from the cutting hardware 11 and 12 of the first and second embodiments shown in FIG. 1 and FIG. Leading steel 1
A large number of cutting tools 17a for cutting the rear surface of the rear end portion and the surface of the front end portion of the trailing steel material 6 are attached. These cutting tools 17a are also the cutting tools 11 and 12 of the cutting hardware 11 and 12.
As with 2a, the line connecting the cutting points has a slight taper 17b so that all pressure contact parts of the steel material can be cut with an even load.
Are attached to have.

In the third embodiment shown in FIG. 3, while the pressure contact surface is covered with a reducing flame atmosphere obtained by igniting the reducing flame burners 4 and 10, the cutting metal article 17 is pulled out similarly to the above. 3 is used to pull out in an obliquely upper right direction in FIG. 3 to simultaneously descale or cut the rear surface of the trailing end portion of the preceding steel material 1 and the surface of the leading end portion of the trailing steel material 6.

FIG. 4 shows a fourth embodiment of the hot steel joining apparatus of the present invention.
The cutting hardware 18 used in this fourth embodiment is the cutting hardware 17 of the third embodiment shown in FIG.
Similarly to the above, a cutting tool 18a for cutting the back surface of the trailing end portion of the preceding steel material 1 and the surface of the leading end portion of the trailing steel material 6 is attached to both the front and back surfaces. This cutting tool 18a is also the cutting hardware 1
Like the bites 11a, 12a and 17a of 1, 12 and 17, though not shown in the drawing so that all the pressure contact parts of the steel material can be cut with a uniform load, the lines connecting the cutting points are attached so as to have a slight taper. ing.

In the fourth embodiment shown in FIG. 4, the cutting hardware 18 is arranged in the width direction of the preceding steel material 1 and the following steel material 6 held in parallel in the vertical direction, and the cutting hardware 18 held in such a state. While the rear surface of the rear end portion of the steel material 1 and the surface of the front end portion of the trailing steel material 6 are covered with a reducing flame atmosphere obtained by igniting the reducing flame burners 4 and 10, the cutting metal piece 18 of FIG. Leading steel material 1 by pulling out in the direction perpendicular to the paper surface
The rear surface of the rear end portion and the surface of the front end portion of the trailing steel material 6 are simultaneously descaled or cut. In the fourth embodiment,
The cutting surface of the pressure contact surface is machined vertically and horizontally, so the machining allowance is small.

Next, the method for joining hot steel materials according to the present invention will be described. The hot steel joining method of the present invention is performed using the hot steel joining apparatus of the present invention shown in FIGS. 1 to 4, for example, and is performed as follows. The preceding steel material 1 sent on the transport table is stopped when the rear end thereof reaches a predetermined position and clamped by the clamp device 2. After that, in the first, third and fourth embodiments shown in FIGS. 1, 3 and 4, the table roller 3 and the reducing flame burner 4 for the preceding steel material 1 are added to the second embodiment shown in FIG. In this case, the table rollers 3 for the preceding steel material 1 are both raised to a predetermined position, and the rear end of the preceding steel material 1 is brought into contact with the upper die 5 of the press, and then each cutting metal piece 11, 12, 17, 18 Insert in place.

Next, the trailing steel material 6 sent on the carrying table was fixed at a position where its tip end overlaps the trailing end portion of the raised preceding steel material 1 at a constant interval, that is, a fixed position. When it reaches the lower die 7, it is stopped and clamped by the clamp device 8.

After that, the first and the first shown in FIGS.
In the third and fourth embodiments, the raised reducing flame burner 4 and the reducing flame burner 10 previously arranged at a predetermined position are ignited,
The vicinity of the pressure contact portion on the rear surface side of the trailing end portion of the preceding steel material 1 and the front surface portion of the leading end portion of the trailing steel material 6 is set to a reducing flame atmosphere. Further, in the second embodiment shown in FIG. 2, non-oxidizing gas is supplied from the non-oxidizing gas pipes 15 and 16 into the shielding covers 13 and 14, and the vicinity of the pressure contact portion is made into the non-oxidizing gas atmosphere. Then, in the reducing flame atmosphere or the non-oxidizing gas atmosphere, each of the cutting hardware 11, 12,
17 and 18 are pulled out in a predetermined direction, and the pressure contact portion is descaled and cut.

After the descaling and cutting are completed, the table roller 3 and the upper die 5 are lowered, and the upper and lower dies 5, 7 press the rear end portion of the preceding steel material 1 and the leading end portion of the following steel material 6 into pressure contact with each other. To do.
At this time, before the rear end portion of the preceding steel material 1 and the front end portion of the following steel material 6 are pressure-welded by the upper and lower molds 5 and 7, or when the pressure welding is started, the clamping by the clamp devices 2 and 8 is released, and the steel material is released. Deal with the extension of. When pressure contact is completed,
In the first, third and fourth embodiments shown in FIG. 4, a reducing flame burner 4,1 is used.
0 is extinguished, and in the second embodiment shown in FIG. 2, the supply of the non-oxidizing gas from the non-oxidizing gas pipes 15 and 16 is stopped. After that, the joining device is retracted to the work start position and stands by until joining the next steel material.

In the present embodiment, descaling, cutting and pressure welding are performed in a reducing flame atmosphere or a non-oxidizing atmosphere, but descaling, cutting and pressure welding may be performed in a normal atmosphere. Needless to say. The same applies when the rear end surface of the preceding hot steel material and the rear surface of the leading end of the following hot steel material are pressed together.

[0033]

As described above, according to the present invention,
The entire apparatus becomes smaller and lighter, the operation of each component inside the apparatus is small and simple, and the lifting stroke of the mold can be shortened, so that the time required for the pressure welding can be further shortened. In addition, since the reducing flame of the reducing flame burner device is guarded by the cutting metal and stabilized by using the cutting metal, stronger joint strength can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a first embodiment of a hot steel joining apparatus of the present invention.

FIG. 2 is a schematic explanatory view showing a second embodiment of the hot steel joining apparatus of the present invention.

FIG. 3 is a schematic explanatory view showing a third embodiment of the hot steel joining apparatus of the present invention.

FIG. 4 is a main part explanatory view showing a fourth embodiment of the hot steel joining apparatus of the present invention.

5A and 5B are drawings showing an example of a cutting metal piece used in the embodiment shown in FIGS. 1 and 2, in which FIG. 5A is a side view and FIG. 5B is an enlarged view of a bite mounting portion.

FIG. 6 is a plan view similar to that of FIG.

FIG. 7 is a schematic explanatory view of a method for joining hot steel materials proposed in JP-A-6-335785.

[Explanation of symbols]

 1 Leading Steel Material 2 Clamping Device 4 Reduction Flame Burner 5 Upper Die 6 Upper Steel Die 7 Lower Die 8 Clamping Device 10 Reduction Flame Burner 11 Cutting Hardware 12 Cutting Hardware 13 Shielding Cover 14 Shielding Cover 15 Non-Oxidizing Gas Pipe 16 Non-Oxidizing Gas pipe 17 Cutting hardware 18 Cutting hardware

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Seiji Okada 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Nobuhiro Tazo, Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Address Ishi Kawashima Harima Heavy Industries Co., Ltd. Yokohama Engineering Center (72) Inventor Norio Iwanami No. 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd. Yokohama Engineering Center

Claims (4)

[Claims] 1. When the rear surface or the rear surface of the trailing end of the preceding hot steel material and the front surface or the rear surface of the leading end portion of the following hot steel material are pressure-welded, the preceding hot steel material is the upper die or lower die of the press. In the state of being set in the mold, and in the state of the subsequent hot steel materials being set in the lower mold or the upper mold of the press, the respective pressure contact surfaces under normal atmosphere, reducing atmosphere, and non-oxidizing atmosphere. In any of the above, a method for joining a hot steel material, characterized in that the scale of the steel pressure contact surface is removed by drawing the cutting metal object or the steel material is cut as necessary, and then pressure welding is performed under the same conditions as the drawing of the cutting metal object. . 2. The hot-working steel material according to claim 1, wherein two cutting metal pieces having a cutting tool attached only to the front surface side are pulled out in the opposite directions at the same time from the state where they are upside down and the back surface side is superposed. Joining method. 3. The method for joining hot steel materials according to claim 1, wherein the cutting hardware having the cutting tools attached to both the front and back surfaces is pulled out in one direction. 4. A device for press-contacting the rear surface or rear surface of the front end of the preceding hot steel material with the front surface or rear surface of the front end portion of the subsequent hot steel material, which clamps the rear end portion of the preceding hot steel material. A device, a device for clamping the leading end of the trailing hot steel material, an elevating device for raising the clamped leading or trailing hot steel product by a predetermined amount, and a parallel arrangement in which the clamping device and the elevating device are arranged in a stepped manner. The scale-removing cutting metal piece arranged to be opposed to the press-contact surface of the hot steel material held in, the drawing device for this cutting metal piece, and the range for performing pull-out cutting by these devices, if necessary, A reducing flame burner device that creates a reducing atmosphere, or a shielding cover that forms an non-oxidizing atmosphere if necessary, and an non-oxidizing gas pipe that communicates with this shielding cover, a rear end surface of the preceding hot steel material after the drawing and cutting or Is a joining apparatus for hot steel products, comprising a pressing device for press-contacting the front surface or the back surface of the front end portion of the front surface and the trailing hot steel material.