JP2001205404A - Fettling method in gas cutting of slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fettling method which removes the fins sticking to the lower edges of the gas cut surface of a slab on a slab refining line with small equipment. SOLUTION: This fettling method in gas cutting of the slab consists in disposing nozzles 7 moving in a cutting direction in synchronization with the gas cutting speed of the slab in gas cutting of the slab below the gas cutting position of the slab apart from the rear surface of the slab 1 and blowing the fluid of ultra-high pressure from the nozzles 7 to fittings 12 sticking to the lower edges 16 of the slab cutting surface in synchronization with the gas cutting speed of the slab. Ultra-high pressure water 10 of 80 to 350 MPa is used for the fluid of the ultra-high pressure in this method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of gas cutting of steel materials, and more particularly to the technical field of a deburring method for slab gas cutting.

[0002]

2. Description of the Related Art Gas cutting of steel is a method in which a cut portion is preheated with a gas flame and iron is burned with oxygen to melt the steel. This is the most economical and most common method for cutting carbon steel. But,
Depending on the type of steel and cutting conditions, slag containing iron oxide adheres to the lower edge of the gas cutting surface (hereinafter, the state in which the slag adheres is referred to as burrs). If burrs adhere to the cut surface, after gas cutting, tap off with a hammer or the like to perform deburring, or scrape with a grinder or metal knife and perform deburring to properly finish the gas cut surface of the slab. .

[0003]

According to the conventional method,
For deburring, a deburring place is required separately from the gas cutting place. During the transfer of the slab after gas cutting to the deburring location, the flash cools and increases its adhesive force, and deburring requires more mechanical equipment. In addition, removing a slab after gas cutting from a series of slab refining lines including a gas cutting operation for deburring promotes a decrease in slab temperature and also leads to a decrease in productivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the amount of burrs adhering to the lower edge of the gas cutting surface of a slab by using a small facility at a high temperature with a low adhesion on a slab refining line. It is an object of the present invention to provide a deburring method at the time of slab gas cutting, which removes burrs by spraying an ultra-high pressure fluid onto the lower edge of the gas cutting surface from below the slab back surface.

[0005]

The gist of the present invention is that a nozzle which moves in the cutting direction in synchronization with the gas cutting speed of the slab at the time of slab gas cutting is provided below the gas cutting position of the slab remote from the back surface of the slab. Ultra-high pressure fluid from
This is a method for removing burrs at the time of slab gas cutting, characterized by spraying the burrs attached to the lower edge of the slab cut surface.

The above deburring method is used for cutting a slab gas in which the ultrahigh pressure fluid is ultrahigh pressure water of 80 MPa to 350 MPa.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, when gas is cut from a slab, the nozzle provided below the slab gas cutting position, which is separated from the back surface of the slab, is used when the burr has a small adhesive force at a high temperature.
Since the ultra-high pressure fluid is sprayed on the beam attached to the lower edge of the gas cutting surface, the flash is blown off by the ultra-high pressure fluid and easily removed from the lower edge of the gas cutting surface. For this purpose, in synchronization with the movement of the gas cutting torch, that is, the cutting speed, the nozzle for spraying the ultra-high pressure fluid onto the burrs attached to the lower edge of the gas cutting surface is also moved. For ultra-high pressure fluids,
Ultra-high pressure water can be used as a liquid such as a gas that does not react with the steel material at a high temperature, such as a nitrogen gas.

[0008] In order to completely remove the burrs adhering to the lower edge of the gas cutting surface with ultra-high pressure water, a pressure of 80 MPa or more is required. When sprayed on the lower edge, the lower edge of the cut surface of the slab is shaved by the ultra-high pressure water, so that the slab shape is deteriorated and, consequently, the shape of the rolled steel plate may be deteriorated. Therefore, the pressure of the ultra-high pressure water is limited to the range of 80 MPa to 350 MPa. It is not necessary to limit the temperature of the ultra-high pressure water to be used.

As a result, deburring on the slab refining line can be performed with a small facility, so that it is not necessary to set up a deburring place and move to the deburring place.
The decrease in the temperature of the slab is suppressed, and the productivity is also improved.

[0010]

The present invention will be described below with reference to examples.
1 and 2 are views for explaining a deburring method at the time of cutting a slab gas according to the present invention. FIG. 1 is a front view, and FIG. 2 is a side view. As shown in the drawing, two torches 2 are provided so that gas can be cut from both ends of the slab 1 toward the center, and a crater 3 is attached to a lower end of each torch 2. At the upper end of the torch 2, a conduit 4 for supplying preheated combustion gas, cutting oxygen, and preheated oxygen to the torch 2 is provided. The torch base is moved by the driving device 15 in the slab width direction (horizontal direction) and the slab thickness direction (vertical direction) so that the position of the torch 2 can be adjusted according to the slab width and the slab thickness. 5. Further, the torch base 5 is moved on a rail 6 by a driving device (not shown) along the longitudinal direction of the slab 1 (in the direction perpendicular to the slab width direction) so that the torch position can be adjusted in accordance with the gas cutting position of the slab. ).

On the other hand, the nozzle 7 for spraying ultra-high pressure water
Below the gas cutting position of the slab away from the back of the slab,
It is provided at the end of a conduit 8 for supplying ultra-high pressure water to a nozzle 7. When the gas is cut, the nozzle 7 adheres to the lower edge 16 of the gas cutting surface of the slab as shown in the schematic diagram of FIG.
In order to blow off the 12 with ultra-high pressure water, it faces the lower edge 16 of the gas cutting surface of the slab 1, that is, the direction of the attached burr 12. The arrow in FIG. 3 indicates the direction of the nozzle that discharges ultra-high pressure water. The nozzle 7 connects the conduit 8 to the slab 1
By moving the torch 2 in and out of the slab in the cutting direction in synchronization with the moving speed of the torch 2 from both ends of the width toward the center, the torch 2 can be moved in synchronization with the cutting speed. Further, the nozzle 7 can be moved following the torch 2 even when the torch 2 moves in the slab longitudinal direction. The ultrahigh-pressure water generator connected to the other end of the conduit 8 and the driving device of the conduit 8 are not shown. In addition, the nozzle 7 can be moved in the vertical direction so that the nozzle 7 can be moved in the vertical direction with respect to the back surface of the slab depending on the state of the burrs attached to the lower edge of the gas cutting surface.

After the slab is blown off by a flame (cutting oxygen) 9 as shown in FIG. 2, the nozzle 7 applies an ultra-high pressure to the burrs 12 attached to the lower edge 16 of the slab cut surface as shown in FIG. Since the water 10 is sprayed, the nozzle 7 is delayed from the passage time of the torch 2 by this time difference, but the moving speed is the same for the torch 2 and the nozzle 7.

At the time of gas cutting, there are slags which adhere to the lower edge of the slab cut surface and those which fall directly from the slab cut surface.
As shown in (1), drop directly into a sluice (not shown). On the other hand, the burrs 12 attached to the lower edge of the cut surface of the slab are blown off from the lower edge of the cut surface by the sprayed ultra-high pressure water 10 as shown in FIG. Then, the blown-out burrs 12 are formed into a plate-like guard together with the ultra-high pressure water 10.
It is received at 13 and falls into a sluice.

In this embodiment, as shown in FIG. 2, a slab (width 2120 mm, thickness 280 mm) 1 conveyed by the conveyance roller 14 is crater size: diameter 10 to 20 mm, cutting oxygen pressure: 0.8.
~1MPa (8~10kgf / cm ^2), the combustion gas pressure: 0.4 to 0.7 MPa (. 4 to
The gas was cut in the width direction at 7 kgf / cm ² ) and at a cutting speed of 300 to 450 mm / min. The diameter of the nozzle 7 at this time is 0.3 mm,
The pressure of the ultra-high pressure water 10 is 350 MPa, and the discharge water amount is 5.5 l / min. As a result, the high-temperature burrs having a small adhesive force attached to the lower edge of the cut surface of the slab were completely removed, and a normal cut surface was obtained. By using ultra-high pressure water, burrs can be removed with a small amount of discharge water, so even when cutting high temperature slabs for warm charging and direct rolling, the temperature drop of the cut surface is small, It does not hinder warm charging into the heating furnace or direct rolling. In addition, by changing the roll interval at a position where the torch is provided on the transport roller, the change width of the position of the torch 2 that can respond to the change of the cutting length of the slab is widened. Note that the deburring effect is further improved by including an abrasive such as a shot or a cut wire in the ultra-high pressure water. It is desirable to install a plurality of torches.

[0015]

As is apparent from the above description,
According to the present invention, burrs adhering to the lower edge of the gas cutting surface of the slab can be removed at a high temperature when the adhering force is small by spraying an ultra-high pressure fluid. In this case, deburring can be performed, so that it is not necessary to move to the deburring place and the deburring place, and the temperature of the slab is suppressed from being lowered, and the productivity is improved.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a deburring method at the time of gas cutting of a slab according to the present invention.

FIG. 2 is a side view illustrating a deburring method at the time of gas cutting of a slab according to the present invention.

FIG. 3 is a schematic view showing a position of a flash adhering to a lower edge of a gas cutting surface of a slab according to the present invention at the time of gas cutting and a direction of a nozzle for discharging ultra-high pressure water indicated by an arrow.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Slab, 2 ... Torch, 3 ... Crater, 4 ... Conduit, 5 ... Torch stand, 6 ... Rail, 7 ... Nozzle, 8 ... Conduit, 9 ... Flame, 10 ... Ultra high pressure water, 11 ... Slag, 12 ... Burr , 13 ... guard, 14 ... transport roller, 15 ... drive device, 16 ... lower edge of the gas cutting surface.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B24C 1/00 B24C 1/00 B

Claims (2)

[Claims] When a slab gas is cut, a nozzle which moves in a cutting direction in synchronization with a gas cutting speed of the slab is provided below a gas cutting position of the slab remote from a back surface of the slab, and an ultra-high pressure fluid is supplied from the nozzle to the slab. A deburring method at the time of slab gas cutting, characterized by spraying a flash attached to a lower edge of a cut surface. 2. The deburring method according to claim 1, wherein the ultrahigh pressure fluid is ultrahigh pressure water of 80 MPa to 350 MPa.