JPS6239068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting device used to remove flaws from a high-temperature material supplied from a blooming facility or a continuous casting facility. The conventional fusing device has a nozzle unit U ₁ as shown in the example in Fig. 1.
~ U ₆ has a manifold 11 at the bottom and uses a piston 12 to set the supply range of O ₂ , gas, etc. according to the material surface, so the range other than the flawed part of the material is also shown in Figure 2. As shown, the entire surface was to be melt-cut at random. In FIG. 2, 1 is the material, 10 is the flaw in the material, and the shaded area is the area to be melted.

Therefore, when carrying out hot direct rolling of materials or charging hot pieces into a heating furnace using conventional cutting equipment, it is necessary to increase the cutting depth, especially to ensure the quality of the material. Therefore, the amount of melting in areas other than the flawed area directly leads to an increase in metal loss and a decrease in yield.

One way to reduce this yield loss is, for example, by combining a top surface partial melting device, a reversing machine, and a top surface partial melting device.

A melting start device is installed on both the upper and lower surfaces (4th
9) in the figure, a method in which partial melt cutting is performed at the location of the flaw in a short period of time on both the upper and lower surfaces at the same time.

A method has been proposed in which the width of the melting spark is constantly expanded from a narrow width (width: 50 to 100 mm) to a predetermined width at the location where the flaw occurs.

In this method, the partial melt cutting equipment is dispersed and a reversing machine is required, so the equipment becomes bulky, and the temperature of the hot rolled material decreases, so there are problems in terms of energy saving.

The above method is ideal as a cutting technique, but as will be described later, it is practically difficult to install equipment for partial cutting with a cutting start device on the bottom surface, The cutting equipment itself is too complicated to be practical.

The present invention solves these problems and prevents an increase in metal loss when carrying out hot direct rolling or hot charging into a heating furnace, making it possible to improve the yield of the material and simplifying the equipment. This makes it possible to carry out hot partial melt cutting.

That is, the present invention provides a method for cutting flaws on the surface of a high-temperature material by supplying O ₂ and gas from each of a plurality of nozzle units held in a hot cutting device. Preheating is started simultaneously from the location of the flaw, including the nozzle unit parts corresponding to other flaws, and after preheating is complete, while the high-temperature material is conveyed in the longitudinal direction, only the corresponding nozzle unit part is heated with O ₂ and gas for melting. squirt out,
The hot partial melting method is characterized by cutting to the tailmost end of each flaw, and O ₂ is removed from each of a plurality of nozzle units in the hot melting equipment to cut the flaw on the surface of the high-temperature material. In the method of melt cutting by supplying gas, the upper surface of the material is melted by a melting start device only at the nozzle unit part that corresponds to the same width range as the flaw at the location where the flaw occurs while conveying the high temperature material. and melt cutting to the tail end position of each flaw, while the lower surface of the material is machined from the first flaw position in the longitudinal direction from the end of the material, including the nozzle unit parts corresponding to other flaws. At the same time, start preheating,
After preheating, the high-temperature material is conveyed in the longitudinal direction, and O ₂ and gas are ejected from the corresponding nozzle unit to perform cutting up to the tail end of each flaw, and the upper and lower surfaces are simultaneously removed. This is a hot partial cutting method characterized by the following:

FIG. 3 shows an example of the configuration of peripheral equipment when the hot partial melting method according to the present invention is employed.

A material such as a slab or bloom is supplied by a blooming mill 21 or a continuous casting machine 22 . The supplied material is passed through a hot flaw detector 23 and a cutting pattern editing control device 24 using a technically known television method or induction heating method while remaining at a high temperature, as shown in FIG. In the illustrated example, information on the range of the flaws 10 to be melted is automatically sent to the fusing device 25 that can employ the hot partial melting method according to the present invention, and selectively and partially melts only the flaws of the material. By cutting, metal loss can be expected to be significantly reduced compared to the conventional method.

The material whose flaws have been automatically removed by the cutting device 25 that can employ the hot partial cutting method according to the present invention can be directly continuously rolled without using the continuous heating furnace 26 depending on the temperature state of the material. The raw material is supplied to the rolling mill 27, or processed by passing through a continuous heating furnace 26 to slightly raise the temperature before being supplied to the continuous rolling mill 27.

First, with reference to FIG. 4, a schematic example of the fusing device 25 will be explained when the hot partial fusing method according to the present invention is adopted in which fusing of the upper surface portion is started via a fusing start device.

A material 1 such as a slab or a bloom is supplied to a fusing apparatus main body 3 by conveyance rollers 2 . If conveyance force for the material being cut is required in addition to the conveyance roller 2, a front pinch roller 4 and a rear pinch roller 5 are installed on the front and rear surfaces of the cutting apparatus main body 3, and the front pinch roller 4 and the cutting A slag target and a smoke hood 6 are installed between the machine body 3 and the machine body 3 to treat slag generated during cutting and to collect smoke. The inside of the fusing device main body 3 is composed of a nozzle unit 7 for the top surface and one side, and a nozzle unit 8 for the bottom surface and one side, both of which are equipped with a start device 9 that can start fusing in a short time at the location where a flaw occurs. has been done.

The nozzle units 7 and 8 are operated vertically and on both sides using an air cylinder system which is generally known. An example of the start device 9 that can start cutting within a short time is an electrode wire device that generates an instantaneous high current value (according to the inventor's investigation, when the material is hot) by using an arc current at the position to be cut. There are methods such as generating 200 to 500 A (for cold conditions, 500 to 1000 A) and using that area as the ignition point.

Next, the nozzle unit 7 for the upper surface and one side surface and the nozzle unit 8 for the lower surface and one side surface will be described in detail with reference to FIG. O ₂ supply pipe so that O ₂ and gas etc. can be supplied to each single unit.
A gas pipe U ₀ and a gas pipe _UG are provided, and the upper and lower surfaces are supplied independently for each single unit according to a signal from the flaw inspection device, so that flaws can be selectively and partially removed. This FIG. 5 is a view seen in the direction of movement of the material 1, U ₀₁ to _{U 06} are O ₂ supply parts to the upper nozzle units I ₁ to I ₆ , and U _G1 to _{U G6} are gas supply parts. part, L ₀₁ is the O ₂ supply part to the side nozzle unit K ₁ paired with the top nozzle unit, L _G
1 is a gas supply part, B ₀₁ to _{B 06} are O ₂ supply parts to the bottom nozzle units J ₁ to _{J 6} , B _G1 to _{B G6} are gas supply parts, and R ₀₁ is paired with the bottom nozzle unit. The O ₂ supply section R _G1 to the side nozzle unit M1 is a gas supply section, and the number of each nozzle unit is appropriately selected depending on the width of the single unit and the width and thickness of the material to be threaded. .

Here, regarding the nozzle unit for the bottom surface, the bad environment around the installation location of the nozzle unit for the bottom surface (splashing water, scattered slag, etc. directly falling) and the fourth
Considering that the installation space is a bottleneck in connection with the smoke hood part as shown in 6 in the figure, there is no equipment that can start cutting within a short time at the location where the flaw occurs.

Next, FIGS. 6 to 10 show a specific example when the hot partial melting method of the present invention is carried out using the apparatus shown in FIG. 4.

FIG. 6 shows the occurrence of the flaw 10 on the upper surface of the material 1, and FIG. 7 shows the occurrence of the flaw 10 on the lower surface of the same material.
An example of a zero occurrence situation is shown, and L in FIG. 7 means the distance from the top end of the material to the flaw located within the shortest distance in the longitudinal direction of the material.

When the hot partial cutting method according to the present invention is applied to the materials shown in FIGS. 6 and 7, the results after the cutting are shown in FIGS. 8 and 9.
Here, Figure 8 shows the results of cutting the upper surface of the material, and Figure 9 shows the results of cutting the lower surface.The shaded area is the cutting area of the flaw, and the double hatched area is the cutting start area for the bottom surface. Since the machine does not have a starting device, excessive cutting will be required.

That is, when the hot partial cutting method according to the present invention is adopted, only the flaws are cut on the upper surface of the material, and the lower surface of the material is preheated at a position L from the top edge of the material as shown in FIG. However, at this time,
For the upper surface, a device is used to stop O ₂ and gas for cutting while preheating the lower surface, and to start cutting again for each nozzle unit after preheating the lower surface (see 9 in Figure 4). ) can be used in combination to automatically restart machining of only the corresponding nozzle unit.

Regarding the lower surface of the material, for the flawed part A in Fig. 7, we stopped cutting the corresponding nozzle unit at the tail end of the flawed part, and for the lower surface of the material, we cut the nozzle unit on the same material surface using the lower surface nozzle unit. Considering that it is desirable to preheat once in terms of processing capacity, preheating is performed at the same position as part A, and the tail end of part B is partially over-cut as shown by double diagonal lines in Fig. 9. Stop cutting of the corresponding nozzle unit at this point.

Therefore, if the hot partial cutting method according to the present invention is adopted, a device (see 9 in Fig. 4) that can start cutting the lower surface in a short period of time, where the environment around the installation site is adverse, can be installed. Hot partial melt cutting is possible without the need for

In addition, regarding the excessively machined part on the lower surface, if the condition of the flaw is as shown in Fig. 10, excessively machined will not occur.In particular, as in continuous casting slag, the flaw is located in the longitudinal direction of the slag. It is very effective to apply the hot partial cutting method according to the present invention to materials that are likely to be produced along the .

Furthermore, in the present invention, due to the limited installation space and technical difficulties as described above, a device (for example, a fourth
9 in the figure)) on both the upper and lower surfaces, the present invention provides a hot partial melt cutting method that can reduce metal loss during melt cutting. FIG. 11 shows an example of a schematic diagram of the cutting apparatus in this case. In Fig. 11, the melting start device 9 of Fig. 4 is not included.
The other device configurations are exactly the same as in FIG. 4.

In other words, with this method, only the nozzle unit part on the same width range that corresponds to the first flaw on either the upper or lower surface in the longitudinal direction of the material is preheated from the end of the material, and the preheating by the corresponding nozzle unit is completed. rear,
While conveying the high-temperature material in the longitudinal direction, hot partial melting is possible by ejecting O ₂ and gas for melting only at the corresponding nozzle unit part, and cutting until the very end of each flaw part. .

12 to 17 show specific examples of the hot partial melting method of the present invention carried out using the apparatus shown in FIG. 11.

FIG. 12 shows an example of the occurrence of scratches on the upper surface of the material, and FIG. 13 shows an example of the occurrence of scratches on the lower surface of the same material. L ₁ in FIG. 12 and L ₂ in FIG. 13 each mean the distance from the top end of the material to the flaw located within the shortest distance in the longitudinal direction of the material.

When the hot partial cutting method of the present invention is applied to the materials shown in FIGS. 12 and 13, the results after cutting are shown in FIGS. 14 and 15. Here, Fig. 14 shows the results of fusing the upper surface of the material, and Fig. 15 shows the fusing results of the lower surface. The shaded area is the flawed area of the flaw, and the double shaded area is the area of excessive fusing. It is.

That is, when the hot partial melting method according to the present invention is adopted, the number of preheating times for the same material is one time for the upper and lower surfaces of the material, and the position is one of the flaws occurring on the upper and lower surfaces of the material. In the examples shown in Figures 12 and 13, there is a relationship between L ₁ and L ₂ of L ₁ < L ₂ , so L on the top surface of the material is According to position ₁ , preheat the flaw with the fusing nozzle unit in the area corresponding to the flaw, and after preheating, discharge O ₂ and gas for fusing from the fusing nozzle unit in the corresponding area to start fusing. I will do it.

In other words, regarding the upper surface of the material, for part A in Figure 12, cutting of the corresponding nozzle unit is stopped at the tail of the flaw, and for part B, preheating is performed at the same position as part A to partially B
Cutting of the corresponding nozzle unit is stopped at the tail part of the part. Also, regarding the bottom surface of the material, see C in Figure 13.
As for parts and parts D, preheating is performed at the same position as part A to partially perform excessive machining, and the machining of the corresponding nozzle unit is stopped at each tail part.

Therefore, if the hot partial cutting method according to the present invention is adopted, the mechanism inside the main body of the cutting apparatus does not include a device that can start cutting within a short time at the location where the flaw occurs. It is extremely simplified and there are fewer occurrences of failures.

Furthermore, if the hot partial cutting method according to the present invention is adopted, even the partially excessively cut parts can be removed as shown in FIGS. 16 and 17 (Figures 16 and 17 show the top and bottom surfaces of the same material ), hot partial welding according to the present invention will not occur if the flaws are in the situation shown in (a), and the hot partial welding according to the present invention is particularly effective for materials where flaws are likely to occur along the longitudinal direction of the slab, such as continuous cast slabs. Adopting the cutting method is very effective.

As described above, according to the hot partial melting method according to the present invention, the following effects can be expected.

1. It is possible to improve the yield of the material by preventing an increase in metal loss when carrying out hot direct rolling of the material or hot charging into a heating furnace.

2. Because there is no complicated device installed on the bottom or both the top and bottom of the cutting machine to start cutting within a short time in a bad environment or where installation space is a bottleneck, there is almost no breakdown and it is practical. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the nozzle unit and manifold part of a conventional fusing device, Fig. 2 is a diagram showing the range of material fusing by the conventional method, and Fig. 3 is a diagram showing the hot partial fusing method according to the present invention. FIG. 4 is a schematic diagram showing an example of a cutting apparatus according to the present invention, and FIG. 5 is a block diagram of a nozzle unit of the cutting apparatus according to the present invention, and FIGS. The figures show a specific example when the hot partial melting method according to the present invention is adopted. Fig. 6 is a diagram showing the occurrence of flaws on the upper surface of a slab, and Fig. 7 is a diagram of the occurrence of flaws on the lower surface of the same slab. Figure 8 shows the results of cutting on the upper surface of the slab, and Figure 9 shows the results of cutting on the lower surface of the slab.
FIG. 0 is a diagram showing an example of a specific flaw occurrence situation when the hot partial melting method according to the present invention is employed and no excessive solvent portion is generated. Further, Fig. 11 is a schematic diagram showing an example of a fusing apparatus not equipped with a fusing start device according to the present invention, and Figs. A specific example is shown when the partial melt cutting method is adopted. Figure 12 is a diagram of the occurrence of scratches on the upper surface of the slab, Figure 13 is a diagram of the occurrence of scratches on the lower surface of the same slab, and Figure 14 is a diagram of the occurrence of scratches on the lower surface of the same slab. 15 shows the result of cutting the upper surface of the slab, FIG. 15 shows the result of cutting the lower surface of the slab, and FIGS. 16 and 17 show the excessively removed part when the cutting apparatus according to the present invention shown in FIG. 11 is used. FIG. 16 is a diagram showing a specific example of a flaw occurrence situation when no flaws occur, and FIG. 16 shows the top surface of the slab, and FIG. 17 shows the bottom surface of the slab. In the figure, 1 is the material, 2 is a conveyance roller, 3 is the cutting device main body, 4 is a front pinch roller, 5 is a rear pinch roller, 6 is a slag target and a smoke hood part, 7 is a nozzle for the top surface and one side, 8 is a nozzle for the lower surface and one side, 9 is a starting device, 10 is a flawed part, 11 is a manifold, 12 is a piston, 2
1 is a blooming rolling machine, 22 is a continuous casting machine, 23 is a hot flaw detector, 24 is a control device for editing a cutting pattern,
25 is a cutting device, 26 is a continuous heating furnace, 27 is a continuous rolling mill, and U is a nozzle unit.

Claims (1)

[Scope of Claims] 1. In a method for cutting a flaw on a surface of a high-temperature material by supplying O ₂ and gas from each of a plurality of nozzle units contained in a hot cutting device, Preheating is started at the same time from the first flaw location to the nozzle unit parts corresponding to other flaws, and after preheating is completed, while the high temperature material is conveyed in the longitudinal direction, only the corresponding nozzle unit parts are heated with O ₂ for melting. A hot partial melt cutting method characterized by blowing out gas and cutting to the tailmost end of each flaw. 2. In a method of cutting flaws on the surface of a high-temperature material by supplying O ₂ and gas from each of a plurality of nozzle units held in a hot cutting device, the upper surface of the material is cut while the high-temperature material is conveyed. Cutting is started via the cutting start device only on the part of the nozzle unit that corresponds to the same width range as the flaw at the location where the flaw occurs, and is cut to the tail end of each flaw. Preheating is started simultaneously from the first flaw position in the longitudinal direction, including the nozzle unit parts corresponding to other flaws, and after preheating is completed, the high temperature material is conveyed in the longitudinal direction while only the corresponding nozzle unit parts are melted. A hot partial melt cutting method characterized in that cutting O ₂ and gas are ejected to cut the tail end of each flaw, and the upper and lower surfaces are simultaneously cut.