JPH07251203A - Method and apparatus for continuous hot rolling of steel material and flying crop shear used therefor - Google Patents

Abstract

(57) [Abstract] [Purpose] A flying crop shear that cuts the joints of two or more long steel strips for hot rolling by laser welding during continuous hot rolling, and a continuous using the flying crop shear. A hot rolling method and apparatus are provided. [Structure] When joining long steels for hot rolling and continuously hot rolling, the tip of the steel material is a tip cutting blade in which the upper cut blade is located on the opposite side of the steel material of the downcut blade during cutting. Cutting with the tail end of the steel material, a flying crop shear that cuts with a tail end cutting blade where an upper cut blade is located on the advancing side of the steel material of the down-cut blade at the time of cutting, and a tip cutting of a plurality of steel materials using this A method and apparatus for continuous hot rolling of steel material, in which tail end cutting is sequentially performed and the tail end cutting surface of the preceding hot rolling steel material and the tip cutting surface of the subsequent hot rolling steel material are butted and joined by laser welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous hot rolling method and apparatus for steel products and a flying crop shear used therefor.

[0002]

2. Description of the Related Art In the hot rolling of steel materials, scratches and shape defects due to no tension, especially in the so-called unsteady parts of the front and tail portions of steel materials, poor strip thickness due to threading speed, poor temperature due to acceleration and deceleration, and poor surface quality. In order to eliminate the deterioration of the order yield, defective part removal work, and smoothing plate work, which are caused by, etc., in recent years, multiple long steel strips for hot rolling have been sequentially joined and rolled at a predetermined continuous speed. So-called continuous hot rolling methods have been tried.

In this continuous hot rolling method, a steel material which has been subjected to rough hot rolling and is supplied to a continuous hot rolling mill, or a long steel material for hot rolling such as high temperature thin-wall continuous casting slab (flat or coiled) The tip and tail end are cut in advance by applying a flying crop shear, and the whole or part of the tail end cutting surface and the tip cutting surface between the steel materials are welded and treated to make many long strips for hot rolling. A method is conceivable in which steel materials are hot-rolled sequentially with the same rolling schedule or while a plurality of rolling schedules are continuously changed while being relay-changed, rolling is divided and cut, and a plurality of winders are alternately wound.

As the welding and joining means, butt electric welding, crimping, laser welding and the like have been studied, but laser welding is advantageous from the viewpoints of speed, joint strength and quality of the joint. In laser welding, it is required that the tail end cutting surface and the tip end cutting surface between the steel materials have a parallel relationship in which the entire surfaces are in contact at the time of butting.

On the other hand, in a flying crop shear, which uses a steel material in advance as a means capable of cutting the tip and tail end at low cost and at high speed, generally, a tip cutting blade and a tail cutting blade are rotated by a predetermined rotation around the outer circumference of each pair of rotary drums. The cutting blades are arranged side by side at an angle, and the upper cutting blades and the down cutting blades of each cutting blade are arranged in the same positional relationship during cutting. For example, the upper cut blade is arranged so as to be located on the side of the down cut blade opposite to the steel material when cutting. And vice versa.

[0006]

As shown in FIG. 4 (a), the action of cutting and removing the crop C1 at the tip of the steel material S by the flying crop shear is performed by the peripheral speed of the drums DM1, DM2 rather than the transfer speed of the steel material S. To cut off
At the time of this cutting, the anti-crop side of the steel material S is pushed up by the belly b of the upper cut blade UDC1, but is restrained by the spine a of the down cut blade DC1 and the shearing side roller table RT1, and the crop side is the crop discharge pit P1. It is cut by the down-cut blade DC1 without being constrained by the roller table RT2 on the exit side, and the constrained cutting surface F1 by the down-cut blade DC1 becomes a flat surface and the unconstrained cutting surface F2 becomes a curved surface of the lower chord.

As shown in FIG. 4B, the action of cutting and removing the crop C2 at the tail end of the steel material S is performed by cutting the drums DM1 and DM2 at a peripheral speed smaller than the steel material S transfer speed. At the time of cutting, the anti-cropping side of the steel material is unconstrained by the down-cut blade DC2, so the unconstrained cutting surface F4 by the down-cut blade DC2 does not become a perfect flat surface, but is close to the curved surface of the lower chord. In the figure, P2 is a crop discharge pit on the entrance side of the flying crop shear FCS.

In this way, the tip and tail crops C1,
Since the cutting surface for joining between the steel materials S from which C2 is removed becomes the curved tail end cutting surface F3 and the flat tip cutting surface F1, it is not suitable for the laser welding joining as it is, and the curved tail end cutting surface F3 is formed. Secondary processing such as hot grinding was essential. However, if the continuous hot rolling speed is increased, this secondary treatment becomes impossible in terms of time. Further, in order to install the secondary treatment equipment between the flying crop shear and the continuous hot rolling mill, it is sufficient to receive a large regulation in relation to auxiliary equipment such as other one-stage or two-stage descaling equipment. The function cannot be obtained, and in some cases, installation becomes impossible.

[0009]

The present invention provides excellent means for solving the above-mentioned problems, and is characterized by the following four points. (1) When joining long steel materials for hot rolling and performing hot rolling continuously, the tip of the steel material is cut by using a flying crop shear in which an end cutting blade of the steel material is arranged on the outer periphery of a rotary drum. In the case of, the drum peripheral speed is made higher than the steel material transfer speed and the downcut blade is cut by the tip cutting blade where the upper cut blade is located on the opposite side of the steel material, and the drum peripheral speed is cut when cutting the tail end of the steel material. The cutting speed is set lower than the steel material transfer speed, and cutting is performed sequentially with the tail end cutting blade where the upper cut blade is located on the steel material advancing side of the down-cut blade. A continuous hot rolling method for steel products, characterized in that the cut end faces of the steel products for rolling are butted and joined by laser welding.

(2) In a flying crop shear in which a tip cutting blade and a tail cutting blade of a long steel for hot rolling are provided side by side at a predetermined rotation angle on the same rotary drum, the upper cutting of the tip cutting blade is performed. Arranging the blade in a relationship of being positioned on the anti-advance side of the steel material of the down-cut blade during cutting, and arranging the upper-cut blade of the tail cutting blade in a relationship of being positioned on the advancing side of the steel material of the down-cut blade during cutting. A flying crop shear for continuous hot rolling of steel materials.

(3) At the inlet side of the continuous hot rolling apparatus, the tip cutting blade and the tail cutting blade of the steel material are provided on the same rotary drum along the traveling direction of the long steel material for hot rolling. ) Or arranged on the outer periphery of a separate rotary drum, and the upper cutting blade of the tip cutting blade is arranged in a relationship of being located on the side opposite to the steel material of the down cutting blade at the time of cutting, and the upper cutting blade of the tail cutting blade is cut. Sometimes with a flying crop shear arranged in a relationship located on the advancing side of the steel material of the down-cut blade,
A joint having a laser welding joint device and a pair of clamps that can move the running welding region of the laser welding joint device and clamp each of the cutting tail end portion of the preceding steel material and the cutting tip end portion of the following steel material in a butted state A continuous hot rolling apparatus for steel products, comprising a clamp device and a high speed shear and a plurality of strip winding devices provided on the exit side of the continuous hot rolling mill.

(4) The tip cutting blade and the tail cutting blade of the steel material are arranged on the outer circumference of the same rotary drum or different rotary drums along the traveling direction of the hot rolled long steel material, and the tip cutting blade is provided. The upper-cut blade of the down-cut blade is arranged in a relationship positioned on the anti-advancing side of the steel material of the down-cut blade during cutting, and the upper-cut blade of the tail cutting blade is arranged in a relationship of being positioned on the advancing side of the steel material of the down-cut blade during cutting. A pair of a flying crop shear, a laser welding joining device, and a pair of clamps that can move the running welding area of the laser welding joining device and clamp the cutting tail end of the preceding steel material and the cutting tip end of the following steel material in abutting state. A joint clamp device having a clamp, a descaling device, a continuous hot rolling mill, a cooling device, a first pinch roll, a high speed shear, a second pinch roll, and a third pinch roll. And hot run table which is interposed a Chiroru, a plurality of strips retractor and continuous hot rolling apparatus of a steel material, characterized in that the was allowed sequential arrangement.

[0013]

As shown in the embodiment of FIG. 1 (a), the operation of cutting and removing the crop C1 at the tip of the steel material S by the flying crop shear of the present invention is performed by changing the peripheral speed of the drums DM1 and DM2 to the steel material S transfer speed. Since it is cut into a larger size, the anti-crop side of the steel material is restrained cutting by the spine a of the down-cut blade DC1 and the roller table RT, the crop side is unconstrained cutting, and the constrained cutting surface F1 by the down-cut blade DC1 is a flat surface. The restraint cutting plane F2 becomes the curved surface of the lower chord. Further, the action of cutting and removing the crop C2 at the tail end of the steel material S is to cut by making the peripheral speed of the drums DM1 and DM2 larger than the transfer speed of the steel material S, so that the anti-cropping side of the steel material is the spine a of the downcut blade DC2 and the roller. The table RT is used for restraint cutting, and the crop side is unconstrained. Therefore, the constrained cutting surface F1 by the downcut blade DC2 becomes a flat surface, and the unconstrained cutting surface F2 becomes a curved surface of the lower chord.

In this way, the tip and tail crops C1,
The cutting surfaces for joining between the steel materials S from which C2 has been removed are flat cutting surfaces F3 and tip cutting surfaces F1 having a parallel relationship with each other.
Since the face-to-face contact can be surely achieved with each other, it can be applied to the laser welding joining as it is, and secondary processing such as grinding processing of the cut surface is completely unnecessary and continuous with the flying crop shear. The regulations on installation of laser welding equipment between hot rolling mills and auxiliary equipment such as descaling equipment will be greatly relaxed.
Further, it is possible to realize high-level stable operation of continuous hot rolling and to advantageously increase the rolling speed.

[0015]

EXAMPLES Examples of the present invention will be described below with reference to FIGS. Flying Crop Shear FCS shown in Figure 1
Is a down-cut blade DC for cutting the tip of the steel material on the outer periphery.
1 and a rotary drum DM1 in which a downcut blade DC1 for cutting the tail end of steel is arranged at a position symmetrical to this, an upper cut blade UDC1 for cutting the tip of the steel on the outer periphery, and a tail end of the steel material at a position symmetrical to this Upper cutting blade UDC2 for cutting
And a rotary drum DM2 in which the upper cutting blade UDC1 for cutting the tip is arranged so as to be positioned on the side of the down-cutting blade DC1 opposite to the steel material S at the time of cutting, and the upper cut for cutting the tail end. The blade UDC2 is arranged so as to be positioned on the advancing side of the steel material S of the downcut blade DC2 at the time of cutting. The operation of this configuration is as described above.

2 to 3 show an example of the whole structure of a continuous hot rolling apparatus in which the flying crop shear FCS is arranged. 2 to 3, as shown in FIG. 2, the heating furnace 1 and the vertical scale breaker V are arranged in the direction in which the steel material moves.
SB, first rough rolling mill R1, second rough rolling mill R2 (reversing mill), tandem third rough rolling mill R3 and fourth rough rolling mill R4, winding with a heat-retaining box as shown in FIG. Machine 3 and rewinding machine 4, leveler 5, flying crop shear FCS having the above-mentioned configuration, and running laser welding welding device 7 for welding the abutting portion of the cutting tail end of the preceding steel S1 and the cutting tip of the following steel S2 , A joining having a pair of clamps 6 and 8 that can move the running welding region of the laser welding joining device 7 and clamp each of the cutting tail end of the preceding steel S1 and the cutting tip of the following steel S2 in a butted state Section clamping device CR, descaling device 9, 7-stand continuous hot finishing mill 10 as shown in FIG. 2, cooling device 11
And a first pinch roll 12, a hot run table 16 provided with a high-speed flying shear 13 for dividing the finished rolled strip into a required unit weight, a second pinch roll 14 and a third pinch roll 15, The strip winding devices 17 and 18 are sequentially arranged.

Roller tables RT1 and RT2 are arranged before and after the flying crop shear FCS via cutting crop discharge pits P1 and P2. This equipment uses a slab 2 extracted from three heating furnaces 1, a vertical scale breaker VSB, and four rough rolling mills R1 to R4.
High temperature steel plate (long steel material for hot rolling) rough rolled by S
While keeping 1 warm, temporarily wind it into a coil with the winder 3,
This coil Co is transferred to the rewinding machine 4, and the rewinding leveler 5 corrects the coil flatly while keeping it warm as shown in FIG.
Supply to CS.

Next, the upper cutting blade UDC1 for cutting the tip of the flying crop shear FCS and the down cutting blade D
The tip of the coil is cut at C1 as shown in FIG. 1 (a), and then it is supplied to the 7-stand continuous hot finishing mill 10 through the clamp device CR and the descaling device 9 and hot finish rolled. . The tail end of the high temperature steel material S1 rewound from the rewinding machine 4 while keeping warm is cut by the upper end cutting blade UDC2 and the down cutting blade DC2 for cutting the tail end of the flying crop shear FCS as shown in FIG. rear,
While moving between the clamps 6 and 8 of the clamp device CR, in parallel with this process, the high temperature steel plate S1 coil Co
The rewinding machine 4 that has rewound the coil immediately receives the next roughly pressed high-temperature steel plate S2 coil Co that has already been wound on the winder 3 and rewinds it, and the tip portion thereof is processed in the same manner as the preceding high-temperature steel plate S1. Flying Crop Shear FC via Leveler 5
Cut with the S upper cutting blade UDC1 for cutting the tip,
The clamp device CR is moved between the clamps 6 and 8, and its cut surface is butted against the trailing end cut surface of the preceding moving high temperature steel plate S1 for clamping. With this, the clamp device CR is moved by the transfer force of the steel plate.

As shown in FIG. 3, the running laser welding welding device 7 for welding the abutting portion between the clamps 6 and 8 has a laser beam fixed light source 7a, a steel plate moving direction movable mirror 7b, and a steel plate thickness direction moving mirror 7c. Main components of the steel plate width direction movable condensing mirror 7d and the CCD camera 7e are set, and the high temperature steel plates S1 and S2 are welded by irradiating and welding a laser beam along the abutting portion while moving in synchronization with the moving speed of the abutting portion. Complete the joining. After this clamp device CR
Opens the steel plate and returns to the original standby position for driving. The high temperature steel plates S3 ... Sn are joined by sequentially repeating the above operation, and continuously supplied to the continuous hot finish rolling mill 10 to perform hot finish rolling to a predetermined size. As a modified example of this example, another position of the flying crop shear FCS may be installed on the upstream side of the winder 3.

[0020]

[Effect of the invention] With the above equipment, width 1000 mm x 34 mm thickness x 6
It was possible to join 30 coils of high-temperature steel plate coils of 0 m length and continuously hot finish-roll to a total coil width of 1000 mm × 2 mm thickness, and after rolling, separately wind into a single-weight 16 ton coil. With this equipment, width 1000 mm x 34 mm thickness x 6
20m high temperature steel coil with 0m length and width 1050mm ×
20 coils of 34 mm thick x 57 m long high temperature steel plate coil are joined, and continuous hot finish rolling can be performed into two types of width 1000 mm x 1.8 mm thickness and width 1050 mm x 2 mm thickness. The coil could be wound separately.

In all of the above rolling examples, all the coils were free from damage such as breakage at the joints, and stable continuous hot finish rolling could be carried out. In addition, the occurrence rate of scratches, shape defects, thickness width defects, temperature defects, and surface quality defects was approximately 0.3%, which is a significant improvement over the conventional hot finish rolling rate of 1.4% in high temperature steel sheet units. It was possible to improve the order yield of products, and to eliminate defective part removal work and adjusting plate work.

[Brief description of drawings]

1A and 1B are explanatory views showing an embodiment of a flying crop shear of the present invention.

FIG. 2 is a simplified bird's-eye view showing an embodiment of the device of the present invention for carrying out the method of the present invention.

FIG. 3 is an explanatory diagram showing a main configuration of the apparatus shown in FIG.

4A and 4B are explanatory views showing a conventional flying crop shear.

Claims (4)

[Claims] 1. When joining a long steel material for hot rolling and continuously hot rolling, a tip of the steel material is used by using a flying crop shear in which an end cutting blade of the steel material is arranged on the outer periphery of a rotary drum. At the time of part cutting, the drum peripheral speed is made higher than the steel material transfer speed, and the tip cutting blade in which the upper cut blade is located on the counter-advancing side of the steel material of the down-cut blade is used to cut the tail end of the steel material. The drum peripheral speed is made lower than the steel material transfer speed, and cutting is performed sequentially with the tail cutting blade where the upper cut blade is located on the traveling side of the steel material of the down-cut blade, and the tail cutting surface of the steel material for preceding hot rolling is performed. And a method for continuous hot rolling of steel products, characterized in that the cut end surfaces of the steel products for subsequent hot rolling are butted and joined by laser welding. 2. A flying crop shear in which a tip cutting blade and a tail cutting blade of a long steel for hot rolling are provided side by side at a predetermined rotation angle on the outer periphery of the same rotary drum, and an upper cutting blade of the tip cutting blade. Is arranged in a relationship of being located on the anti-advance side of the steel material of the down-cut blade during cutting, and the upper-cut blade of the tail cutting blade being arranged in a relationship of being located on the advancing side of the steel material of the down-cut blade during cutting. Flying crop shear for continuous hot rolling of characteristic steel materials. 3. A leading end cutting blade and a tail end cutting blade of the long steel for hot rolling are provided on the inlet side of a continuous hot rolling apparatus in the same rotating drum along the traveling direction (equipmentally advantageous). Or placed on the outer periphery of a separate rotating drum, the upper cutting blade of the tip cutting blade is arranged in a relationship located on the anti-progress side of the steel material of the down-cut blade at the time of cutting, when cutting the upper-cut blade of the tail cutting blade The flying crop shear located in the relationship of the downcut blade on the advancing side of the steel material, the laser welding joining device, and the traveling welding area of the laser welding joining device can be moved to make the cutting tail end of the preceding steel material and the trailing steel material And a joining portion clamping device having a pair of clamps for clamping each in a state of abutting the cutting tip end of the device, and a high speed shear and a plurality of strip winding devices on the exit side of the continuous hot rolling mill. A continuous hot rolling apparatus for steel products, characterized by being provided with. 4. A tip cutting blade and a tail cutting blade of the steel material are arranged on the outer circumference of the same rotary drum or different rotary drums along the traveling direction of the long steel material for hot rolling. The upper-cut blade is arranged in a relationship in which it is located on the anti-advance side of the steel material of the down-cut blade during cutting, and the upper-cut blade of the tail cutting blade is arranged in a relationship in which it is located on the advancing side of the steel material of the down-cut blade during cutting. The flying crop shear, the laser welding joining device, and the traveling welding region of the laser welding joining device can be moved, and a pair that clamps the cutting tail end of the preceding steel product and the cutting tip end of the following steel product in abutting state Clamping Device with Clamp, Descaling Device, Continuous Hot Rolling Mill, Cooling Device, First Pinch Roll, High Speed Shear, Second Pinch Roll, and Third Pin A continuous hot rolling apparatus for steel products, characterized in that a hot run table provided with a chill roll and a plurality of strip winding devices are sequentially arranged.