JP2011036880A - Scarfing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scarfing device that can suppress reaching of stuck scarfing slag to a nozzle-forming block, even if the scarfing slag scattering from a molten pool sticks a shoe block when a lower face of a steel piece is scarfed. <P>SOLUTION: The scarfing device 4 for scarfing the lower face of a steel piece is characterized in that the device includes a shoe block 1 which is made to face the steel piece in scarfing the steel piece, a body 20 to which the shoe block is attached, and a nozzle-forming block which is mounted on the body and attached in contact to the lower face of the shoe block and which has the nozzle formed for jetting a scarfing gas, wherein an end on the nozzle side of the shoe block protrudes over the nozzle-side contact end 2a which comes in contact with the lower face of the shoe block in the nozzle-forming block. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a scarfing device that melts and removes surface defects of a steel piece after continuous casting.

  If rolling is performed with defects present on the surface of the steel slab after continuous casting, there may be product defects after rolling. For this reason, after preheating the surface of the steel slab with combustion gas, the scarfing that blows off the surface defects formed on the steel slab surface layer by spraying oxygen jet and utilizing the oxidation exothermic reaction of iron-oxygen is performed. (For example, refer to Patent Document 1).

FIG. 3 is a schematic cross-sectional view for explaining a conventional scarfing apparatus.
The scarfing device 14 has a shoe block 11, and the shoe block 11 is attached to the main body 20. Since this shoe block 11 is directly adjacent to the steel piece to be welded, its inside has a water cooling structure. Further, a crater forming block is attached to the main body 20, and this crater forming block forms a crater for blowing out the cutting gas, and has a first block 12 and a second block 13. ing.

  Further, the scarfing device 14 has a gas flow path 15 formed by the first and second blocks 12 and 13, and a crater from which the cutting gas is ejected is formed at the tip of the gas flow path 15. Is formed. This crater melts the steel piece surface by spraying a cutting gas containing a combustible gas and oxygen gas on the steel piece.

  The first block 12 is attached in contact with the lower surface of the shoe block 11, and the end portion on the crater side of the shoe block 11 is on the crater side that contacts the lower surface of the shoe block 11 in the first block 12. It is located so as not to overhang from the contact end 12a.

FIG. 4 is a view for explaining a steel piece slicing process using the scarfing apparatus shown in FIG. 3.
As shown in FIG. 4, combustible gas and oxygen gas are ejected from a crater formed at the tip of the gas flow path 15 of the scarfing device and ignited to form a heating flame so that the lower surface of the steel slab 16 is sufficiently covered. After heating to, the cutting starts. Next, when the molten pool 17a is generated on the lower surface of the steel slab 16 and the welding is confirmed, the cutting gas is ejected from the scarfing apparatus at a predetermined speed while the scarfing apparatus is fixed. It is moved by a transport roll (not shown) in the opposite direction, that is, in the direction of the arrow 21 shown in FIG. Thereby, the lower surface of the steel slab 16 is continuously welded.

JP 2000-15434 A (paragraphs 0019 to 0026)

  As shown in FIG. 4, when the bottom surface of the steel slab 16 is sliced by using a conventional scarfing device, the cutting noro 17 c scattered from the molten pool 17 a generated on the bottom surface of the steel slab 16 It adheres to the end portion on the crater side of the shoe block 11 closest to the welding surface. The cutting scraper 17b adhering to the end of the shoe block 11 accumulates along the first block 12, and the gas channel 15 may be blocked by the deposited cutting scraper 17b. As a result, the flow of the cutting gas ejected from the crater at the tip of the gas flow path 15 is disturbed, which causes quality deterioration such as tiger cutting on the cutting surface of the steel piece 16.

  In addition, since the cutting scraper 17b adhering to the vicinity of the tip of the gas flow path 15 blocks the crater portion, the cutting is interrupted at a relatively small number of treatments, and the cutting attached to the vicinity of the tip of the gas flow path 15 is performed. Maintenance is required to remove the cutting nose 17b adhering to the ends of the noro 17b and the shoe block 11. This increases the non-operating time of the scarfing device, leading to a reduction in processing capacity and an increase in maintenance costs.

  Further, the cutting edge 17c scattered from the molten pool 17a and adhering to the end portion of the shoe block 11 is transmitted to the first block 12 and deposited, whereby the end portion of the first block 12 is worn out. If the wear of the end of the first block 12 is severe, cracks or irregularities occur on the surface of the first block 12. These cracks and irregularities become a starting point for further attachment of the cutting blade 17c, and the new cutting blade 17c is attached to the attached cutting blade 17b, so that the cutting blade 17b attached to the vicinity of the tip of the gas flow path 15 is obtained. Will be further promoted. For this reason, the state management of the first block 12 becomes an important management problem of sticking, and frequent maintenance of the first block 12 is required.

  Therefore, the present invention can suppress the adhesion of the attached cutting surface to the crater forming block even if the cutting surface scattered from the molten pool adheres to the shoe block when the lower surface of the steel slab is cut. It is an object to provide a scarfing device.

  The inventors of the present invention investigated in detail the welding noro 17b attached to the scarfing device 14. As a result, it was found that the welding blade 17b attached only to the shoe block 11 easily peeled off, whereas the welding blade 17b deposited from the shoe block 11 to the first block 12 hardly peeled off. Further, it has been clarified that the reason why the cutting blade 17b transmitted to the first block 12 is difficult to peel is because the cutting blade 17b bites into the contact end 12a of the shoe block 11 and the first block 12. . Then, if a method for preventing the cutting end from biting into the contact end is studied, and the end of the shoe block protrudes beyond the contact end, the cutting cut attached to the shoe block is transmitted to the first block. I found it difficult.

  Further, the present inventors can easily remove the shoe block from the shoe block by the pressure of the cutting gas even if it is deposited and reaches the gas flow path if it is attached to only the shoe block, thereby inhibiting the gas flow. Confirmed that it will disappear.

  In order to prevent adhesion to the first block, the overhang is preferably 3 mm or more. On the other hand, when the overhang of the shoe block is applied to the gas flow line, the shoe block itself disturbs the gas flow. Therefore, it is preferable that the overhang of the shoe block does not reach the gas flow line.

  One aspect of the present invention is a scarfing device for cutting a lower surface of a steel piece, a shoe block that faces the steel piece when the steel piece is cut, a main body to which the shoe block is attached, A crater forming block that is attached to a main body and is in contact with the lower surface of the shoe block, and is formed with a crater that blows out a cutting gas, and an end of the shoe block on the crater side is The scarfing device is characterized in that it protrudes from the contact end on the crater side that contacts the lower surface of the shoe block in the crater forming block.

  Moreover, the scarfing apparatus which concerns on 1 aspect of this invention WHEREIN: It is preferable that the edge part by the side of the said crater of the said shoe block is located in the outer side of the cutting gas fluid ejected from the said crater.

  The scarfing device according to an aspect of the present invention may further include a smoothing unit that smoothes a gas flow formed in the crater forming block and formed in the crater that ejects the cutting gas. The outer edge of the cutting gas fluid may be defined by the smoothing portion.

  Moreover, the scarfing apparatus which concerns on 1 aspect of this invention WHEREIN: It is preferable that the length which the edge part by the side of the said crater of the said shoe block protrudes is 3 mm or more.

  By applying one aspect of the present invention, even when the cutting scrap scattered from the molten pool adheres to the shoe block when the lower surface of the steel slab is cut, the attached cutting scrap is attached to the crater forming block. It is possible to suppress transmission.

(A) is typical sectional drawing for demonstrating the scarfing apparatus by embodiment, (B) is sectional drawing to which the crater part of the scarfing apparatus shown to (A) was expanded. (A), (B) is a figure for demonstrating the cutting process of the steel piece using the scarfing apparatus shown in FIG. It is typical sectional drawing for demonstrating the conventional scarfing apparatus. It is a figure for demonstrating the cutting processing of the steel piece using the scarfing apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

  FIG. 1A is a schematic cross-sectional view for explaining a scarfing device according to an embodiment of the present invention, and FIG. 1B shows a crater portion of the scarfing device shown in FIG. It is expanded sectional drawing.

  As shown in FIG. 1A, the scarfing device 4 has a shoe block 1, and the shoe block 1 is attached to a main body 20. Since the shoe block 1 is directly adjacent to the steel piece to be welded, the inside thereof has a water cooling structure. Further, a crater forming block is attached to the main body 20, and this crater forming block forms a crater that blows out the cutting gas, and has a first block 2 and a second block 3. ing.

  Further, the scarfing device 4 has a gas flow path 5 formed by the first and second blocks 2 and 3, and a crater from which cutting gas is ejected is formed at the tip of the gas flow path 5. Is formed. This crater melts the steel piece surface by spraying a cutting gas containing a combustible gas and oxygen gas on the steel piece.

  The first block 2 is attached in contact with the lower surface of the shoe block 1, and the end portion on the crater side of the shoe block 1 is on the crater side that contacts the lower surface of the shoe block 1 in the first block 2. It is located so as to protrude from the contact end 2a.

  As shown in FIG. 1 (B), the length 10 at which the end portion on the crater side of the shoe block 1 protrudes, that is, the length between the end portion on the crater side of the shoe block 1 and the contact end 2a. The length 10 is preferably 3 mm or more.

  Further, the end portion on the crater side of the shoe block 1 is located outside the cutting gas fluid 9a ejected from the crater. That is, as shown in FIG. 1 (B), the outer edge on one side of the cutting gas fluid 9a ejected from the crater at the tip of the gas flow path 5 is indicated by a gas streamline 9 slightly widened. The cutting gas fluid 9 a is ejected inside the region indicated by the gas flow line 9. Therefore, it is preferable that the upper limit of the length 10 at which the end portion on the crater side of the shoe block 1 protrudes is a length that the end portion on the crater side of the shoe block 1 does not reach the gas flow line 9.

  The first block 2 of the crater forming block is formed with a smoothing portion 2b for smoothing the gas flow of the cutting gas, and the smoothing portion 2b is located in the vicinity of the crater for blowing out the cutting gas. . The smoothing portion 2b defines an outer edge on one side of the cutting gas fluid ejected from the crater at the tip of the gas flow path 5. That is, the gas stream line 9 shown in FIG. 1B is defined by the smoothing unit 2b. The gas flow line 9 is along a dotted line connecting the tip 5a of the gas flow path 5 and the tip 2c of the smoothing portion 2b.

  The smoothing portion 2 b is a portion that is recessed toward the shoe block 1 from the extension of the gas flow path 5. Note that the shape of the smoothing portion 2b is not limited to the shape shown in FIG. 1B, and other shapes can be used as long as the shape can smooth the gas flow.

2 (A) and 2 (B) are views for explaining a steel piece forging process using the scarfing apparatus shown in FIG.
As shown in FIG. 2 (A), flammable gas is ejected in the direction of the arrow from the crater formed at the tip of the gas flow path 5 of the scarfing device 4, and oxygen gas is ejected and ignited. After forming the heating flame and sufficiently heating the steel slab 6, the pressure of the oxygen gas ejected from the crater is increased to start the cutting. As the combustible gas, CO gas, natural gas, propane gas, or the like can be used.

  Next, when the molten pool 7a is generated on the lower surface of the steel slab 6 and the welding is confirmed, the cutting gas is ejected from the scarfing apparatus at a predetermined speed while the scarfing apparatus is fixed. It is moved by a transport roll (not shown) in the opposite direction, that is, in the direction of the arrow 21 shown in FIG. Thereby, the lower surface of the steel slab 6 is continuously welded. At this time, the steel piece 6 is moving along the adjacent shoe block 1.

  A part of the cutting noro 7c scattered from the molten pool 7a generated on the lower surface of the steel piece 6 when the lower surface of the steel piece 6 is subjected to the cutting is a cutting gas ejected from the crater at the tip of the gas flow path 5 The other part of the sprayed cutting blade 7c blown off by the slag adheres to the crater side end of the shoe block 1 closest to the surface of the steel piece 6 to be cut. As described above, the end portion on the crater side of the shoe block 1 protrudes from the contact end 2a that contacts the first block 2 of the crater forming block, and therefore, the welding scrap adhered to the end portion of the shoe block 1 It can suppress that 7b is transmitted to the 1st block 2. FIG. Then, by projecting the end portion of the shoe block 1 from the contact end 2a, the end portion of the shoe block 1 can be brought close to the cutting gas ejected from the crater. As a result, the end portion of the shoe block 1 adheres to the end portion of the shoe block 1. It is possible to blow away the dripping cutting with the cutting gas. Further, when the cutting scraper 7b adhering to the end of the shoe block 1 is accumulated and reaches the gas stream line 9 (see FIG. 1B), FIG. As shown in FIG. 2, the pressure from the cutting gas easily removes the shoe block 1 and does not obstruct the gas flow. Therefore, it is possible to suppress the gas flow path 5 from being blocked by the cutting blade adhering to the end portion of the shoe block 1. Therefore, it is possible to reduce the maintenance frequency for removing the cutting chips adhering to the vicinity of the front end of the gas flow path 15, and the cutting that is ejected from the crater at the front end of the gas flow path 5 even if a relatively large number of continuous treatments are performed. The gas flow is not disturbed, and it is possible to suppress the deterioration of quality such as tiger cutting on the surface of the steel slab 16 being cut.

  Further, by setting the length 10 between the end portion of the shoe block 1 and the contact end 2a to be 3 mm or more, the welding blade 7b adhering to the end portion of the shoe block 1 is transmitted to the first block 2 and is changed to the first block 2. It is possible to more effectively suppress the adhesion of the cutting chips to the one block 2.

  Further, by positioning the end of the shoe block 1 outside the cutting gas fluid ejected from the crater, that is, the overhang of the shoe block 1 does not reach the gas stream line 9, the end of the shoe block 1 is melted. The cutting process can be performed while preventing the flow of the cutting gas from being disturbed without interfering with the flow of the cutting gas.

  Further, by suppressing the welding blade 7b adhering to the end portion of the shoe block 1 from being transmitted to the first block 2, the removal operation of the adhesion blade is reduced. For this reason, the non-operating time of the scarfing device is reduced, leading to an improvement in processing capacity.

  In addition, since the inside of the shoe block 1 has a water cooling structure, when the steel slab is hot-cut, the function of the main body 20 can be buffered.

DESCRIPTION OF SYMBOLS 1,11 Shoe block 2,12 1st block 2a, 12a Contact end 2b Smoothing part 2c Tip of smoothing part 3,13 2nd block 4,14 Scarfing device 5,15 Gas flow path 5a Gas flow path No. 6,16 Steel slab 7a, 17a Melting pool 7b, 7c, 17b, 17c Nozzle cutting 9 Gas stream line 9a Cutting gas fluid 10 Length 20 over which the end of the crater side of the shoe block protrudes 20 Main body 21 Arrow

Claims (4)

In the scarfing device that cuts the lower surface of the steel piece,
A shoe block that opposes the steel piece when the steel piece is sliced;
A body to which the shoe block is attached;
A crater forming block attached to the main body, attached in contact with the lower surface of the shoe block, and formed with a crater for blowing out the cutting gas,
Comprising
A scarfing device, wherein an end of the shoe block on the crater side protrudes from a contact end on the crater side that contacts a lower surface of the shoe block in the crater forming block.   The scarfing apparatus according to claim 1, wherein an end portion of the shoe block on the crater side is located outside a cutting gas fluid ejected from the crater.   3. The scarfing apparatus according to claim 2, further comprising a smoothing portion that is formed in the crater forming block and smoothes a gas flow formed in the crater that ejects the cutting gas, and the cutting gas fluid The scarfing device is characterized in that an outer edge of the scarf is defined by the smoothing portion.   The scarfing device according to any one of claims 1 to 3, wherein a length over which the end portion on the crater side of the shoe block projects is 3 mm or more.

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