JPH08103805A - Steel cutting method by flying crop shear - Google Patents

Abstract

PURPOSE: To enable stable continuous hot finish rolling completely not having damage of breakage, etc., of joint by specifying the difference between cutting rotating speed at the tip part/tail part of steel and transfer speed of steel while the tip/tail of steel having specified transfer speed is cut. CONSTITUTION: A long steel for hot rolling is cut at the tip and tail of steel having 0.5-2.0m/sec transfer speed by using a flying crop shear. In this case, while the crop 1 of tip of steel S is cut, the difference between a rotating speed of drums DM1, DM2 and steel transfer speed is set +0.1 to 1.5m/sec, a constraint cutting face F1 by down cut and DC1 is made to flat. Further, while cutting the crop 2 of tail of steel S, the difference between a cutting rotating speed and steel transfer speed is set to -0.5 to 1.5m/sec, a constraint cutting face F3 by down cut and DC2 is made to flat. By this method, generation of scratch and shape defect is improved, almost eliminating defective part removing work and finishing passing work.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In the hot rolling of steel products, scratches and shape defects due to no tension, especially in so-called unsteady parts of the front and tail parts of steel products, strip width / thickness defects due to threading speed, temperature defects due to acceleration, and surface quality defects. In order to reduce the order yield and the work of removing defective parts and the work of adjusting plates as much as possible, the long steel strips for hot rolling have been sequentially joined in recent years and continuously rolled at a predetermined speed. So-called continuous hot rolling methods of treating have been attempted.

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) In advance, the front and rear ends are cut with a flying crop shear, and the whole or part of the rear end cutting surface and the front end cutting surface between the steel materials are welded and joined together to produce a large number of long lengths for hot rolling. The steel material is hot-rolled sequentially with the same rolling schedule or while a plurality of schedules are continuously changed by relay, hot rolling is performed after the rolling, and the rolling treatment is performed alternately by a plurality of winding machines.

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 rear end cutting surface and the front 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, a flying crop shear, which is used as a means capable of cutting the front and rear ends of steel material at a high speed in advance and at a low cost, generally has a front cutting blade and a rear cutting blade each of which is a pair of rotary drums. Are placed side by side at a predetermined rotation angle on the outer periphery of the cutting blade, and the upper cutting blade and the down cutting blade of each cutting blade are arranged in the same positional relationship at the time of 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. There is also an example of the opposite arrangement.

[0006]

As shown in FIG. 3 (a), the action of cutting and removing the crop C1 at the tip of the steel material S by the flying crop shear has the following effects.
Since the peripheral speed of the drums DM1 and DM2 is increased from 8 to 2.0 m / sec for cutting, the anti-crop side of the steel material S is pushed up by the belly b of the upper cut blade UC1 during this cutting, but the down cut blade DC1 Is cut by the down-cut blade DC1 while being restrained by the spine a and the roller table RT1 on the entrance side, and the crop side is on the crop discharge pit P2 without being restrained by the roller table RT2 on the exit side. The constrained cutting surface F1 by the cutting blade DC1 becomes a flat surface, and the unconstrained cutting surface F2 becomes a curved surface of the lower chord. As shown in FIG. 3 (b), the steel material S
The operation of cutting and removing the crop C2 at the rear end of the drum DM1 and D is performed from the steel material S transfer speed of 0.5 to 1.5 m / sec.
Since the peripheral speed of M2 is cut at a low speed, the uncropped side of the steel material is unconstrained by the downcut blade DC2 during this cutting, and the unconstrained cutting surface F3 by the downcut blade DC2 is a complete plane. However, the state is close to the curved surface of the lower chord. In the figure, UC2 is an upper cut blade, and P1 is a crop discharge pit on the inlet side of the flying crop shear FCS.

In this way, the front and rear end crops C1,
Since the cutting surface for joining between the steel materials S from which C2 has been removed becomes the curved rear end cutting surface F3 and the flat front end cutting surface F1, it is not suitable for the laser welding joining as it is, and the curved rear end cutting surface F3 is Secondary processing such as hot grinding was essential. However, if the continuous hot rolling speed is increased, this secondary treatment becomes impossible in time. In addition, in order to install the secondary treatment equipment between the flying crop shear and the continuous hot rolling mill, it is subject to significant regulation in relation to other auxiliary equipment such as one-stage and two-stage descaling equipment. Sufficient function cannot be obtained, and in some cases, installation becomes impossible.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides an excellent means for solving the above problems, which is characterized in that a tip cutting blade and a tail end of a long steel material for hot rolling are provided. In a flying crop shear with cutting blades arranged at a predetermined rotation angle on the outer circumference of the same rotary drum, the upper cutting blade of the tip cutting blade is arranged in a relationship in which it is positioned on the side opposite to the steel material of the downcut blade during cutting. The upper cutting blade of the tail cutting blade is arranged so as to be positioned on the advancing side of the steel material of the down-cut blade at the time of cutting, and using this flying crop shear, the transfer speed is 0.5 to 2.0 m / se.
When cutting the front end and the rear end of the steel material of c, the cutting rotational speed and the steel material transfer speed difference are +0.1 to 1.5 at the front end of the steel material.
m / s, and at the time of cutting, the downcut blade is cut by the tip cutting blade where the upper cut blade on the opposite side of the steel material is located, and at the rear end portion of the steel material, the speed difference is -0.5 to 1.
The cutting method is a steel material cutting method with a flying crop shear, which is characterized in that the cutting speed is 5 m / s and that the cutting material is cut with a trailing cutting blade having an upper cutting blade located on the traveling side of the down cutting blade.

[0009]

Operation and Embodiments The operation of the present invention will be described 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, a rotary drum DM1 in which a down-cut blade DC1 for cutting the rear end of the steel material is arranged at a position in which the steel material is cut, an upper cut blade UC1 for cutting the front end of the steel material in the outer circumference, and a steel material in a position in which the steel material is cut at the surface-symmetrical position Upper cut blade UC2 for rear end cutting
And the upper drum for cutting the tail end, the upper cutting blade UC1 for cutting the tip is arranged in a relation of being positioned on the side of the down-cut blade DC1 opposite to the steel material S at the time of cutting. The cutting blade UC2 is arranged so as to be located on the advancing side of the steel material S of the downcut blade DC2 at the time of cutting.

Before and after the flying crop shear FCS, roller tables RT1 and RT2 are arranged via cutting crop discharge pits P1 and P2. The action of cutting and removing the crop C1 at the tip of the steel material S is to cut, as shown in FIG. 1 (a), by setting the peripheral speed of the drums DM1 and DM2 to be higher than the steel material S transfer speed of 1.8 to 2.0 m / sec. Therefore, the back side of the down-cut blade DCI is on the anti-crop side of the steel material.
Then, the roller table RT performs constraint cutting, the crop side performs unconstrained cutting, the downcut blade DCI constrains the cutting surface F1 into a flat surface, and the unconstraining cutting surface F2 into a curved surface of the lower chord.

Further, as shown in FIG. 1B, the action of cutting and removing the crop C2 at the tail end of the steel material S is performed by the drum DM.
1. The peripheral speed of DM2 is 0.5 to 1.5 m /
Since the cut is made smaller than sec, the side of the steel opposite to the crop is the back a of the down-cut blade DC2 and the roller table R.
Restraint cutting is performed by T, and the crop side is unconstrained. Therefore, the restraining cut surface F by the down cut blade DC2
3 is a flat surface, and the unconstrained cut surface F4 is a curved surface of the lower chord.

In this case, the vertical speed of the cut surface of the steel material is influenced by the relative speed difference between the peripheral speeds of the rotating drums DM1 and DM2 and the traveling speed of the steel material S, and this relationship is shown in FIG. That is, when the tip is cut, the steel material traveling speed is 1.8 to 2.
The drum peripheral speed is +0.5 to 1.5 m / s from 0 m / sec.
By cutting the steel material into large pieces, the cutting surface at the tip of the steel material becomes a plane substantially perpendicular to the horizontal surface of the steel material. On the contrary, when cutting the rear end, the steel material traveling speed is 0.5 to 1.5.
The peripheral speed of the rotating drum is -0.5 to 1.5 m / m from m / sec.
By cutting with a small s, the cut surface of the rear end portion of the steel material can form a plane substantially perpendicular to the horizontal surface of the steel material. As described above, the relative peripheral speed of the rotating drum influences the verticality of the cut surface of the steel material.

In this way, the front and rear crops C1,
The steel material S from which C2 has been removed has a joining cutting surface which is flat and has a rear end cutting surface F4 and a front cutting surface F1 which are parallel to each other. Since it can be applied to welded joints, secondary processing such as grinding processing of the cut surface is completely unnecessary, and incidental equipment such as laser welding jointing equipment and descaling equipment between the flying crop shear and the continuous hot rolling mill is not required. The regulations on the installation of facilities can be greatly relaxed. Then, the high-order stable operation of continuous hot rolling can be realized, and the rolling speed can be advantageously increased.

A high temperature steel plate S obtained by roughly rolling the slab extracted from the heating furnace with a scale breaker and a rough rolling machine.
(Long steel material for hot rolling) is temporarily wound into a coil with a winder while keeping it warm, and this coil is transferred to a rewinder, and while being kept warm from the rewinder, it is flattened by a rewind leveler and the tip of the coil Parts are fed to a Flying Crop Shear FCS of the above construction. Next, the upper cutting blade DC1 for cutting the tip of the flying crop shear FCS and the down cutting blade DCI
After the coil tip is cut as shown in Fig. 1 (a),
It is supplied to the continuous hot finish rolling mill through the clamp device and the descaling device and hot finished rolled.

The rear end portion of the high temperature steel plate S rewound while keeping the heat from the rewinding machine has an upper cut blade UC2 for cutting the rear end of the flying crop shear FCS and a down cut blade DC.
After being cut by UDC2 at 2 as shown in FIG. 1 (b), it moves between both clamps of the clamp device. In parallel with this process, the rewinding machine that rewinds the high temperature steel plate S coil, Immediately receives the next hot-rolled high-temperature steel sheet S coil that has already been wound up on the winder, rewinds it, and rewinds the tip of the coil in the same way as the preceding high-temperature steel sheet S via the leveler to the tip cutting blade of the flying crop shear FCS. It cuts by UDC1 and it moves between the clamps of a clamp apparatus, and the cut surface is made to abut against the trailing end cut surface of the hot plate S which is moving ahead, and it clamps. With this, the clamp device is moved by the transfer force of the steel plate.

While the above operation is sequentially repeated, the high temperature steel sheets S are joined one after another and continuously supplied to a continuous hot finish rolling mill for hot finish rolling to a predetermined size. As a modified example of this example, Flying Crop Shear F
As another arrangement position of the CS, it may be installed on the upstream side of the winder.

Width 1000 mm × 34 mm thickness ×
It was possible to join 30 coils of a high-temperature steel plate coil having a length of 60 m, perform continuous hot finish rolling to a total coil width of 1000 mm × 2 mm thickness, and after rolling, separately wind into a single-weight 16 ton coil. Also, with this equipment, width 1000 mm x 3
20 coils of high-temperature steel plate coil of 4 mm thickness x 60 m length and 20 coils of high-temperature steel plate coil of width 1050 mm x 34 mm thickness x 57 m length were joined together to continuously heat two types of width 1000 mm x 1.8 mm thickness and width 1050 mm x 2 mm thickness. It was possible to finish rolling, and after rolling, it was possible to separately wind into a single-weight 16 ton coil for each size.

[0018]

EFFECTS OF THE INVENTION According to the present invention, there is no damage such as breakage of the joint, and stable continuous hot finish rolling can be carried out. The occurrence rate of scratches, defective shapes, thickness defects, temperature defects, and surface quality defects was about 0.
3%, which is a significant improvement compared to the conventional hot finish rolling rate of 1.4% for high-temperature steel sheets, which greatly improves the product order yield and improves the work of removing defective parts and performing refinement. It is possible to eliminate almost all the work of the pass plate.

[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 diagram showing a relationship between a relative speed difference between a peripheral speed of a line drum and a steel material speed and verticality of a steel material cut surface in the present invention.

FIG. 3 is an explanatory view showing a conventional flying crop shear.

[Explanation of symbols]

 S Steel FCS Flying Crop Shear C1 Tip Crop C2 Rear Crop DM1 Drum DM2 Drum a Cutting blade spine b Cutting blade belly DC1 Downcut blade DC2 Downcut blade UC1 Uppercut blade UC2 Uppercut blade F1, F2, F3, F4 Cut surface P1 Input side crop discharge pit P2 Output side crop discharge pit PT1 Input side roller table PT2 Output side roller table

Claims (1)

[Claims] 1. A flying crop shear in which a tip cutting blade and a tail cutting blade of a long steel material 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-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 located on the advancing side of the steel material of the down-cut blade during cutting, Transfer speed 0.5 to 2.0 m / se using a flying crop shear
When cutting the tip / tail end of the steel material of c, the difference between the cutting rotation speed and the steel material transfer speed is +0.1 to 1.5 at the tip of the steel material.
m / s, and at the time of cutting, the downcut blade is cut by the tip cutting blade where the upper cut blade on the opposite side of the steel material is located, and at the rear end portion of the steel material, the speed difference is -0.5 to 1.
A method for cutting a steel material with a flying crop shear, which is characterized in that the cutting speed is 5 m / s, and the cutting material is cut with a trailing edge cutting blade having an upper cut blade positioned on the traveling side of the steel material of the downcut blade.