KR20110105790A - Hot sgafing apparatus and method of hot scafing steel slab - Google Patents

Abstract

The steel sheet cutting device of the present invention includes a cutting oxygen cylinder having a reference cylinder end portion and a following cylinder end portion, a reference side region into which the cutting oxygen cylinder is supplied, inserted from the following cylinder end portion; A slit nozzle having a piston for partitioning to the following side region to which the cutting oxygen is not supplied, a slit nozzle having a reference side nozzle end, and ejecting the cutting oxygen toward the steel piece from the reference side region of the cutting oxygen cylinder, and The control means for adjusting an insertion position is provided, and the said reference side nozzle edge part is arrange | positioned in the position outside of the reference side edge part of the said steel piece.

Description

HOT SGAFING APPARATUS AND METHOD OF HOT SCAFING STEEL SLAB}

TECHNICAL FIELD This invention relates to the grinding apparatus of a steel slab, and the grinding method of a steel strip. This grinding apparatus has a torch which injects oxygen into the surface of a steel piece.

This application claims priority based on Japanese Patent Application No. 2009-004409 for which it applied to Japan on January 13, 2009, and uses the content here.

In order to improve the quality by removing cracks, surface inclusions, pinholes and the like which are present in the vicinity of the surface of the cast piece produced by continuous casting or the like, a process of injecting oxygen into the steel piece by hot-melting the surface is used. This treatment which is melted by hot is also called Hot Scarfing. As shown in Fig. 4A, since four surfaces of the steel sheet are simultaneously melted by hot, the quality of the steel sheet can be improved at high speed, high efficiency and low cost.

Specifically, fuel gas and oxygen derived from liquefied petroleum gas or coke oven gas are injected into the hot slab, and the surface of the slab is further heated to high temperature by combustion of the fuel gas and oxygen. As a result, oxidative melting of the surface of the steel piece occurs and molten iron is generated. The fuel gas and oxygen used at this time are called preheated fuel gas and preheated oxygen. When the cutting oxygen is sprayed on the surface of the steel sheet from the molten oxygen nozzle, the molten iron and oxygen cause an oxidation reaction, and strong reaction heat is generated. Therefore, an oxidation reaction occurs continuously by continuously moving the molten oxygen nozzle and / or the steel slab, and the melting proceeds.

As shown in FIG. 6A, injection of the cutting oxygen is performed by blowing oxygen from the slit nozzle 5 provided in the torch 1.

By the way, the steel slab manufactured by continuous casting etc. has various widths. Therefore, the welding apparatus is designed so that steel pieces having various widths can be melted. That is, the grinding apparatus is designed to hot-drill four surfaces of the steel strip 10, for example, as shown in Fig. 4A. In detail, the upper surface grinding unit 20a which grinds the upper surface of the steel strip 10, and the lower surface grinding unit 20b which grinds the lower surface of the steel strip 10 (these grinding units are hereafter called optical surface grinding unit 20). May be used), and each of the upper and lower surfaces of the steel slab 10 _MAX having the maximum allowable width can be machined. The upper surface grinding unit 20a and the lower surface grinding unit 20b are respectively connected with the side surface machining unit 22 which grinds one side surface of the steel plate 10 from one edge part (reference side edge part 33). The upper surface machining unit 20a and the lower surface machining unit 20b can slide mutual positions in the width direction of the steel strip 10. When the steel slab 10 having a predetermined width is to be milled, the side surface grinding unit 22 which slides the upper surface grinding unit 20a and the lower surface grinding unit 20b to each other and is connected to the respective grinding units 20a and 20b, 22) is arranged in the position where the side surface of the steel piece 10 of the predetermined width can be melted. As a result, the upper surface machining unit 20a, the lower surface machining unit 20b, and the side surface machining units 22 and 22 optimize the positional relationship with the surface of the steel sheet, and can simultaneously cut the four surfaces of the steel sheet 10. .

Except in the case of steel sheet 10 _MAX having the maximum possible cutting width, for example, as is apparent from FIG. 4A, the cutting target is larger than the cutting possible width of the upper surface grinding unit 20a and the lower surface grinding unit 20b. The width side of the slab 10 is small. Therefore, the part corresponding to the part exceeding the width | variety of the steel slab 10 among the full widths of the upper surface grinding unit 20a and the lower surface grinding unit 20b is that a cutting oxygen, a preheating oxygen, a preheating fuel gas, and a shield fuel gas It is necessary to cope with eruption. The structure for that is demonstrated below with reference to FIGS. 6A-6D.

As shown in FIG. 6A, the torch 1 (a cutting unit) includes a torch unit 3 having a gas ejection nozzle such as a cutting oxygen slit nozzle 5, and a manifold coupled to the torch unit 3 ( Has 2). The manifold 2 includes the cylinders 4, 21b, 21c, 21d to which gas, such as cutting oxygen, is supplied. Hereinafter, with reference to FIGS. 6A-6D, the cutting oxygen cylinder 4 in the manifold 2 of the optical surface grinding unit 20 is demonstrated as an example.

6B, 6C, and 6D are cross-sectional views taken along lines B′-B ′, C′-C ′, and D′-D ′ of FIG. 6A, respectively. In the manifold 2 of the optical surface welding unit 20, the cutting oxygen cylinder 4 is formed as a cavity extended in the steel strip width direction. On the other hand, the slit nozzle 5 which blows off cutting oxygen is arrange | positioned at the torch unit 3. The slit nozzle 5 is provided over the full length of the torch unit 3 in the slab width direction. The cutting oxygen cylinder 4 and the torch unit 5 are connected by a plurality of connecting pipes 6 in parallel over the entire length of the steel strip width direction. When the cutting oxygen is supplied from one location of the cutting oxygen cylinder 4, the cutting oxygen is supplied to the entire steel piece width direction of the slit nozzle 5 via the plurality of connecting pipes 6.

As shown in FIG. 6B, the cutting oxygen cylinder 4 has a reference side end 31 and a following side end 32 that is an end on the opposite side (following side) from the reference side end 31. From the following side end 32, the piston 8 is inserted. The piston 8 is supported by the support 9, and by adjusting the insertion length of the support 9, the insertion position of the piston 8 in the cutting oxygen cylinder 4 can be changed in the slab width direction. have. The other end ((reference side end 31) of the cutting oxygen cylinder 4 is closed. Moreover, as shown in Fig. 4A, when the width of the steel strip 10 to be melted is determined, the steel strip The insertion position of the piston 8 is adjusted according to the width of the 10. Here, when cutting oxygen is supplied to the cutting oxygen cylinder 4, the reference side edge part 33 and the piston ( Cutting oxygen is supplied in the area | region between 8), and cutting oxygen is supplied to the slit nozzle 5. Cutting oxygen is supplied to the area | region between the piston 8 and the following side edge 34 of the cutting oxygen cylinder 4. By performing such a control, even if the width | variety of the steel piece 10 to be melt | dissolved, the cutting oxygen will be ejected only in the width range of the steel piece 10. As shown in FIG.

In the above description, the explanation has been made mainly on the cutting oxygen cylinder 4. However, the manifold 2 includes the preliminary fuel gas cylinder 21b, the preliminary oxygen cylinder 21c, and the shield fuel gas cylinder in addition to the cutting oxygen cylinder 4. It may have 21d or the like. As shown in Figs. 6C and 6D, all of the nuclear cylinders are connected to the respective cylinders by inserting the piston 8 from the following side end 34 and adjusting the position of the pistons, similarly to the cutting oxygen cylinder 4. The gas blowing from each of the nozzles can be limited in accordance with the width range of the steel slab 10.

Even if the temperature of the surface of the steel piece 10 which hot-processes is in a reddish state, except for the flat part of a corner part, the corner part corresponding to four corners of the steel piece 10 is low in temperature. Therefore, in the case where the oxygen injection conditions of the light-surface welding unit 20 are made uniform, the machining of corners having a low temperature may be insufficient. In Patent Literature 1, the molten oxygen cylinder is divided into three chambers: a reference chamber, a surface chamber, and a tracking chamber. The reference side chamber and the following side chamber are disposed so as to correspond to the width direction both ends of the steel strip 10, and the surface chamber is located between them. The cutting oxygen pressure of the reference side chamber and the following side chamber is set higher than that of the surface side chamber. Thereby, the oxygen flow volume (kinetic energy) which blows toward the corner part of the steel piece 10 can be made higher than the oxygen flow rate which blows toward the center part of a steel piece. Therefore, the amount of cut equivalent to the center part of a steel piece can also be ensured also in the corner part with low steel piece temperature. As a result, the steel strip 10 can be uniformly melted over the whole width direction. In this case, the cutting oxygen supply on the following side is formed of a pipe so as to allow oxygen to pass through in order to allow the inside of the support of the piston to be inserted into the cutting oxygen cylinder.

About the tracking side of the optical surface welding unit 20, the insertion position of the piston 8 of a cutting oxygen cylinder is adjusted according to the width | variety of the steel strip 10 (FIG. 4A). Thereby, the supply range of the oxygen supplied from the cutting oxygen cylinder 4 can be matched with the width | variety of the steel strip 10. As shown in FIG. Oxygen supplied to the cutting oxygen cylinder 4 is ejected via the connecting pipe 6 and the slit nozzle 5. By the way, as for the follower side, since the slit nozzle 5 is wider than the width end of the steel piece 10, it is supplied from the connecting pipe 6 near the piston 8 of the cutting oxygen cylinder 5. Oxygen gas spreads outward from the width end of the steel piece 10 in the slit nozzle 5. Therefore, the oxygen gas supply amount in the vicinity of the width | variety edge part of the steel piece 10 showed the tendency to decrease. Moreover, about the reference side 31 of a grinding unit, the side plate 27 is inserted in the edge part of the slit nozzle 5 so that cutting oxygen gas may not leak from the side surface of a torch.

In Patent Literature 2, the stop position of the piston is enlarged more than the width of the steel strip to discharge oxygen, thereby controlling the stop position. Thereby, the shortage of the oxygen gas supply amount of the width | variety of the slab width part in the following side is alleviated, and the effect that a residual amount of residual machining is reduced is acquired.

By using the method described in patent document 1 and patent document 2, it becomes possible to prevent generation | occurrence | production of the residual amount of the machining of the corner part of a steel slab in hot grinding, and the whole four sides of a steel slab can be melted without missing.

Japanese Patent Application Laid-open No. Hei 9-210320 Japanese Patent Application Laid-open No. 2006-102804

As described above, by using the methods described in Patent Documents 1 and 2, it is possible to prevent the generation of the residual amount of the corner portion of the steel sheet during hot grinding, and the entire four sides of the steel sheet can be melted without missing. However, even when the technique described in Patent Literature 1 or Patent Literature 2 is applied, sliver defects may occur continuously in the longitudinal direction due to a constant distance from the end in the vicinity of the width end of the cold rolled steel sheet. The sliver defect is one of the surface quality defects in the cold rolled steel sheet which hot-rolled steel sheets, such as a continuous casting cast piece, and cold-rolled, and is considered to be one of the reasons the alumina inclusions inherent in the vicinity of a steel piece surface. MEANS TO SOLVE THE PROBLEM As a result of investigating the cause of a sliver defect in detail, the present inventors found that the remaining amount of the steel piece corner part did not generate | occur | produce, although the related art described in patent document 1 and patent document 2, for example, the steel piece corner part is a plane other than that. Compared with the part, it turned out that the cutting amount by hot grinding is small. As a result, as shown in FIG. 6B, it turned out that the corner R becomes small in the steel piece corner part 12 after the grinding 42, and the rounding of a corner part is decreasing. And when the corner R of a steel piece corner part is too small, the corner part may be folded and folded on the steel plate surface at the time of subsequent rolling, and this is because of the sliver defect which generate | occur | produces continuously in the longitudinal direction by the distance from the edge part of a cold rolled sheet steel being constant. It was found to be the cause.

Conventionally, about the reference side of the optical surface welding unit 20, the width direction edge part of the slit nozzle which discharges a cutting oxygen was position-aligned in the position corresponded to the edge part of a steel piece. On the other hand, when the width direction edge part of a slit nozzle arrange | positions outward from the edge part of a steel piece, the cutting amount of a steel slab corner part increases, and as shown in FIG. 6A, the steel slab corner part 12 after the grinding 42 It can be seen that corner R can be largely held.

An object of the present invention is to provide a device for cutting steel pieces and a method for cutting steel pieces, which can prevent sliver defects occurring near the width end of a steel sheet.

This invention is made | formed based on the said knowledge, The summary is as follows.

(1) The 1st aspect of this invention is the reference side area | region where the cutting oxygen cylinder which has the reference side cylinder end part and the following side cylinder end part, and is inserted from the following side cylinder end part, and supplies the said cutting oxygen cylinder with the cutting oxygen supply And a slit nozzle having a piston for partitioning into the following side region to which the cutting oxygen is not supplied, a reference side nozzle end, and ejecting the cutting oxygen from the reference side region of the cutting oxygen cylinder toward the steel piece; It is provided with the control means for adjusting the insertion position of a piston, The said reference side nozzle edge part is the steel piece grinding apparatus arrange | positioned in the position outside from the reference side edge part of the said steel piece.

(2) In the grinding apparatus as described in said (1), the said piston may be arrange | positioned outside the following side edge part of the said steel piece.

(3) In the grinding apparatus as described in said (1) or (2), the said reference side area | region is divided into the reference side room and the center room, and the reference side partition board arrange | positioned in the position inside the said reference side edge part of the said steel piece; An extension portion extending from the piston toward the reference side cylinder end portion and an end portion of the extension portion, dividing the reference side area into the center room and the following side room, and being inside the following side end of the steel piece. It is further provided with the following side partition board arrange | positioned at the inside, and the cutting oxygen of pressure higher than the pressure in the said center chamber may be supplied to the said reference side room and the said following side room.

(4) A second aspect of the present invention is a method for grinding a steel sheet using a cutting device including a cutting oxygen cylinder, a piston inserted into the cutting oxygen cylinder, and a slit nozzle communicating with the cutting oxygen cylinder. And a step of supplying the cutting oxygen to the oxygen cylinder, and injecting the cutting oxygen into the steel piece through the slit nozzle disposed outside the reference side end portion of the steel piece.

(5) In the grinding method as described in said (4), you may further include the process of arrange | positioning the said piston outside the following side edge part of the said steel piece.

(6) In the method for grinding steel slabs according to (4) or (5), the reference side region is divided into the reference side chamber and the following side chamber by using a grinding apparatus in which the reference side region is divided into a reference side chamber, a center chamber, and a following side chamber. And supplying the cutting oxygen at a pressure higher than the pressure in the central chamber.

In this invention, the position of the reference side edge part of the slit nozzle which supplies the cutting oxygen to a steel slab optical surface is located outside of a steel piece rather than the width | variety edge part of a steel piece, so that the cutting amount of a steel piece corner part is increased, and the corner of the steel piece corner part after a grinding is carried out. It can hold R large. Thereby, reduction of the sliver defect generation after rolling can be implement | achieved.

It is sectional drawing of the grinding apparatus which concerns on 1st embodiment of this invention.
It is an expanded sectional view of the said grinding apparatus in the vicinity of the reference side edge part.
It is an expanded sectional view of the said grinding apparatus in the vicinity of the following side edge part.
It is sectional drawing of the grinding apparatus which concerns on 2nd Embodiment of this invention.
3A is a torch cross-sectional view of an example of a grinding apparatus used in the present invention.
3B is a cross sectional view of the torch, including a cross section of the connector;
3C is a cross-sectional view of the torch obtained along the line CC of FIG. 3B.
3D is a perspective view showing the reference side end portion of the slit 5 of the torch.
4A is a cross-sectional view of the grinding apparatus.
4B is an enlarged cross-sectional view of the vicinity of the reference side end portion of the grinding apparatus.
It is a figure which shows the cross section of the corner part vicinity of the steel piece which was melted by the grinding apparatus or the grinding method of this invention.
It is a figure which shows the cross section of the corner part vicinity of the steel piece which was melted by the conventional grinding apparatus or the grinding method.
6A is a sectional view of a torch of a conventional machining device.
6B is a cross-sectional view taken along line B′-B ′ of FIG. 6B.
FIG. 6C is a cross-sectional view taken along line C′-C ′ of FIG. 6B.
FIG. 6D is a cross-sectional view taken along the line D′-D ′ of FIG. 6B.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described with reference to FIGS. 1A-1C, FIG.

In FIG. 1A, the grinding apparatus 100a which concerns on 1st Embodiment of this invention is shown. The grinding apparatus 100a which hot-processes four surfaces of the steel strip 10 is a light-surface grinding unit 20 (upper surface grinding unit 20a, lower surface grinding unit 20b), and both side surface grinding units 22 and 22. As shown in FIG. Gas is blown out from the surface of the steel slab 10. As shown in FIG. 1A, one side side cutting unit 22 is fixed to the reference side 31a of the upper surface cutting unit 20a and the reference side 31b of the lower surface grinding unit 20b, respectively.

The light surface cutting unit 20 (upper surface cutting unit 20a and lower surface cutting unit 20b) includes a torch unit 3 having a gas blowing nozzle and a manifold 2 coupled to the torch unit 3. Have As illustrated in FIG. 4A, the manifold 2 includes a cutting oxygen cylinder 4, a preheated fuel gas cylinder 21b, a preheated oxygen cylinder 21c, a shield gas cylinder 21d, and the like. Regarding the cutting oxygen, as shown in FIGS. 3A to 3C, in the cutting oxygen cylinder 4, a plurality of connecting pipes 6 arranged in parallel in the width direction of the steel piece are disposed, and the tip of each connecting pipe 6 is arranged. It is connected to the slit nozzle 5 of this torch unit 3. The piston 8 is inserted into the cutting oxygen cylinder 4 from the following side 32 (following end 34 in FIG. 1A). The piston 8 is supported by the support tool 9 inserted from the following side end 34. The opposite side of the following side 32 is the reference side 31. By supplying gas to the in-cylinder region between the reference side end 33 and the piston 8, the slit nozzle 5 through a connecting pipe 6 disposed at a position between the reference side end 33 and the piston 8. ) Is supplied with cutting oxygen. Thereby, the cutting oxygen is blown out to the steel piece from the specific location of the slit nozzle 5 corresponding to the insertion position of the piston 8. By adjusting the insertion position of the piston 8 by the operation of the support 9 according to the width of the steel strip 10 to be melted, it is possible to eject oxygen to an unnecessary position even when the width of the steel strip 10 is small. It can prevent. The insertion position of the piston 8 is adjusted by a control part (not shown). The control device may be configured to acquire the positional information of the optical surface cutting unit 20 and operate the support tool 9 of the piston 8 based on the positional information. In addition, as shown in FIG. 3D, the side end portion of the slit nozzle 5 is blocked by the side plate 27 with respect to the reference side end portion 33 of the cutting unit, and the cutting oxygen leaks from the side surface of the torch. It is preventing.

About the position of the reference side edge part 33 of the slit nozzle 5 of the optical surface welding unit 20, as shown to FIG. 4A, FIG. 4B conventionally, in the cross section perpendicular | vertical to a steel slab longitudinal direction (a cutting progress direction). And the slit nozzle reference side edge portion 33 were arranged in the vertical direction (hereinafter referred to as the 'steel slab edge repair line 14') in the width direction end portion of the steel strip 10. As a result, compared with the other planar part, the steel piece corner part 12 reduces the amount of cuts by hot cutting. Therefore, as shown in FIG. 5B, it was found that the corner R of the steel sheet corner portion 12 is reduced, so that the rounding of the corner portion 12 is reduced. And when the corner R of the steel piece corner part 12 is too small, the corner part 12 may be folded and folded on the steel plate surface in the subsequent rolling, and this is a distance from the edge part of a cold rolled steel plate, and is longitudinal direction This causes sliver defects that occur continuously.

In the present invention, as shown in FIGS. 1A and 1B, the position of the reference side end portion 33 of the slit nozzle 5 is positioned outside the steel piece 10 than the width end 13 of the steel piece. That is, the slit nozzle reference side edge part 33 is arrange | positioned in the outer part of the steel piece 10 rather than the steel piece edge repair 14. By arranging the slit nozzle 5 of the light-surface cutting unit 20 at such a position and performing hot cutting, the cutting amount of the steel slab corner portion 12 is increased, and the corner R of the steel slab corner portion 12 after grinding is increased. I can greatly support it. In addition, FIG. 5A is a partial sectional view of the steel slab 10 before the grinding, using the grinding apparatus according to the present embodiment, in the vicinity of the steel slab corner portion 12 of the steel slab 41 before grinding and the steel slab 42 after grinding. Indicates. As shown in Fig. 5A, by providing rounding to the slab corner portion 12 after hot melting, it becomes possible to prevent troubles in which sliver defects occur at the slab corner portion equivalents in rolling.

When the distance between the slab end repair 14 and the slit nozzle reference side end 33 is G (see FIG. 1B), the position of the reference side end 33 of the slit nozzle 5 is the width end of the slab 10. If the outer side of the steel piece 10 is set to (13), and G is 10 mm or more, a preferable result can be obtained. More preferably, G is at least 15 mm.

In the torch unit 3 of the grinding unit, as shown in FIGS. 3B and 6A, not only the cutting oxygen slit nozzle 5 that ejects the cutting oxygen, but also the preheating fuel gas nozzle 7b and the preheating oxygen nozzle 7c. And shielded fuel gas nozzle 7d. In addition, in order to supply gas to these nozzles, the manifold 2 has the preheating fuel gas cylinder 21b, the preheating oxygen cylinder 21c, and the shield fuel gas cylinder 21d besides the cutting oxygen cylinder 4. . 6B to 6D show the arrangement in the steel piece width direction of each cylinder in the manifold 2. As apparent from Figs. 6B to 6D, on the reference side 31, the cutting oxygen cylinder 4, the preheating fuel gas cylinder 21b, the preheating oxygen cylinder 21c, and the shield fuel gas cylinder 21d have a steel strip width. It has an end at an equal position in the direction. In addition, the insertion position of the piston 8 is a position which is equal in the slab width direction in any of the cutting oxygen cylinder 4, the preheating fuel gas cylinder 21b, the preheating oxygen cylinder 21c, and the shield fuel gas cylinder 21d. Is placed on.

In the present invention, not only the cutting oxygen slit nozzle but also the preheated fuel gas nozzle 7b, the preheated oxygen nozzle 7c, and the shielded fuel gas nozzle 7d, the position of the reference side end of the nozzle is lower than the width end of the steel piece. It is preferable to locate it outside the steel piece. Thereby, the round piece corner part can obtain sufficient rounding compared with the case where the position of the reference side edge part is only located outside the steel piece rather than the width edge part of a steel piece. In a typical machining unit, as shown in FIGS. 3A to 3C and 6A to 6D, on the reference side 31, the cutting oxygen cylinder 4, the preheating fuel gas cylinder 21b, and the preheating oxygen cylinder 21c. The shield fuel gas cylinder 21d has an end portion at a position equivalent to the width of the steel strip. Therefore, by positioning the reference side end portion of the cutting oxygen slit nozzle outside the steel piece rather than the width end portion of the steel piece, the nozzle of the preheated fuel gas nozzle 7b, the preheated oxygen nozzle 7c, and the shielded fuel gas nozzle 7d may be The position of the reference side end portion can be positioned outside the steel piece rather than the width end of the steel piece.

Also about the slab corner part 12 located in the slit nozzle following side 33, by applying this invention, rounding can be made to the corner part 12 after melting, and the sliver defect after rolling can be reduced. About the following side of the cutting oxygen cylinder 4, the piston 8 is inserted from the edge part, and the position of the piston 8 is adjusted according to the width | variety of the steel piece which injects oxygen. By applying the present invention to both the reference side and the following side of the slit nozzle, rounding can be provided at the corner portions of both the reference side and the following side of the steel piece, so that both ends of the width after rolling can reduce sliver defects. .

Conventionally, as described in Patent Literature 2, it is possible to reduce the remaining amount of machining by improving the stop position of the piston. However, the sliver defect by the lack of rounding of the steel-clad corner part after the melting was generate | occur | produced. In the present invention, not only the cutting oxygen slit nozzle but also the preheated fuel gas nozzle 7b, the preheated oxygen nozzle 7c, and the shielded fuel gas nozzle 7d, the stop position of the piston is outside of the steel piece than the width end of the steel piece. It is preferable to locate at. Thereby, the round piece corner part can obtain sufficient rounding compared with the case where the position of the reference side edge part is only located outside the steel piece rather than the width edge part of a steel piece. As a result, the sliver defect after rolling can also be fully reduced also in the steel piece corner part of a following side. In a typical machining unit, as shown in FIGS. 3A to 3D and 6A to 6D, the arrangement position of the piston 8 is a cutting oxygen cylinder 4, a preheating fuel gas cylinder 21b, and a preheating oxygen cylinder. Both 21c and 21d of shield fuel gas cylinders are arrange | positioned in the same position in the steel piece width direction. Therefore, the piston position of the cutting oxygen slit nozzle is located outside the steel piece rather than the width end of the steel piece, so that the piston arrangement is also applied to the preheated fuel gas nozzle 7b, the preheated oxygen nozzle 7c, and the shielded fuel gas nozzle 7d. The position can be located outside the steel piece rather than the width end of the steel piece.

In FIG. 2, the grinding apparatus 100b which concerns on 2nd Embodiment of this invention is shown. As shown in FIG. 2, in this embodiment, the cutting oxygen cylinder 4 is divided into three regions (rooms) of the reference side region 36, the surface portion region 35, and the following side region 37. The reference side area | region 36 is arrange | positioned from the reference side edge part 33 of the cutting oxygen cylinder 4 in the width direction inner side. The following side region 37 is disposed at a portion in the width direction from the position of the piston 8. The surface portion region 35 is disposed between the reference side region 36 and the following side region 37. It is preferable to supply the cutting oxygen of the pressure higher than the surface area | region 35 to the reference side area | region 36 and the following side area | region 37. FIG.

Since the cutting oxygen of the pressure higher than the surface area | region area 35 is supplied to the reference | standard side area | region 36 and the following side area | region 37, the cutting amount with respect to the corner part 12 vicinity where the slab surface temperature at the time of grinding is low. (Measurement depth) can be made almost equal to the center width of the slab width. The machining oxygen is at a high pressure, for example, 3.2 kgf / cm 2, from the reference side region 36 and the following side region 37 of the cylinder 4, and a normal pressure, eg, from the central surface region 35. For example, it is supplied at 2.8 kgf / cm 2. Due to these pressure differences, a difference is observed in the cutting effect, and the cutting depth of the surface portion and the lower corner portion is roughly the same.

The reference side area | region 36 is 120 mm or more and 280 mm or less in width direction inner side from the reference side edge part 33 of the cutting oxygen cylinder 4, Preferably it is 160 mm or more and 240 mm or less, More preferably, about 200 mm Is placed in the position of. From the reference side edge part 33, 120 mm or more and 280 mm or less, Preferably it is 160 mm or more and 240 mm or less, More preferably, the partition plate 23 is provided in about 200 mm inside, and it partitions from the reference side edge part 33. Cutting oxygen is supplied to the reference side region 36 between the plates 23. The following side area | region 37 is arrange | positioned from the piston 8 position in the width direction inner side 120 mm or more and 280 mm or less, Preferably it is 160 mm or more and 240 mm or less, More preferably, it is arrange | positioned in the site of about 200 mm. From the piston 8, the 2nd piston (2nd partition plate) 24 is provided in the inside of about 120 mm or more and 280 mm or less, Preferably it is 160 mm or more and 240 mm or less, More preferably, about 200 mm, The piston 8 ), The cutting oxygen is supplied to the following side region 37 between the second piston (second partition plate) 24. The support 9 for inserting the piston 8 into the cutting oxygen cylinder is called a pipe 25, and the pipe surface of the support is between the piston 8 and the second piston (second partition plate) 24. The vent hole 26 may be provided in the chamber, and the machining oxygen of the following chamber 37 may be supplied through the inside of the pipe 25.

According to this invention, the reduction of the sliver defect generation after rolling can be implement | achieved. Therefore, the industrial applicability is great.

1: torch
2: manifold
3: torch unit
4: cutting oxygen cylinder
5: slit nozzle
6: connector
7: nozzle
7b: preheat fuel gas nozzle
7c: preheat oxygen nozzle
7d: shield fuel gas nozzle
8: piston
9: support
10: lecture
11: light surface
12: corner
13: width end
14: slab end repair
20: light face machining
20a: Upper face grinding unit
20b: Lower face grinding unit
21b: preheat fuel gas cylinder
21c: preheat oxygen cylinder
21d: shield fuel gas cylinder
22: side cutting unit
23: partition plate (first partition plate)
24: second piston (second partition plate)
25: pipe
26: vent hole
27: shroud
31: Reference side
32: following side
33: reference side end
34: following side end
35: cotton room
36: reference room
37: following room
41: steel sheet before grinding
42: slab after melting

Claims (6)

A cutting oxygen cylinder having a reference side cylinder end and a following side cylinder end;
A piston inserted from an end of the following side cylinder and partitioning the cutting oxygen cylinder into a reference side region to which cutting oxygen is supplied, and a following side region to which the cutting oxygen is not supplied;
A slit nozzle having a reference side nozzle end and ejecting the cutting oxygen toward a steel piece from the reference side region of the cutting oxygen cylinder;
And control means for adjusting the insertion position of the piston,
Said reference side nozzle edge part is arrange | positioned at the position outside of the reference side edge part of the said steel piece, The steel sheet machining apparatus. The steel sheet machining apparatus according to claim 1, wherein the piston is disposed at a position outside of the following side end portion of the steel sheet. The reference side partition plate of Claim 1 or 2 which divides the said reference side area | region into a reference side room and a center room, and is arrange | positioned in the position inside of the said reference side edge part of the said steel piece,
An extension part extending from the piston toward the reference cylinder end;
It is provided at the edge part of the said extension part, Comprising: The following side partition board which divides the said reference side area | region into the said center room and a following side room, and is arrange | positioned inside the said following side edge part of the said steel piece further,
A machining apparatus for a steel slab, wherein the cutting oxygen having a pressure higher than the pressure in the center chamber is supplied to the reference side chamber and the following side chamber. It is a grinding method of the steel piece using the grinding apparatus provided with the grinding oxygen cylinder, the piston inserted in the said grinding oxygen cylinder, and the slit nozzle which communicates with the said grinding oxygen cylinder,
Supplying cutting oxygen to the cutting oxygen cylinder;
And a step of injecting the cutting oxygen into a steel piece through the slit nozzle disposed outside the reference side end portion of the steel piece. The method for machining a steel piece according to claim 4, further comprising a step of arranging the piston outside the following side end portion of the steel piece. The said reference side area | region is the grinding method of the steel piece using the grinding apparatus divided into the reference side room, the center room, and the following side room,
And a step of supplying the cutting oxygen having a pressure higher than the pressure in the center chamber to the reference side chamber and the following side chamber.

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