KR20190086991A - Repair method for scarping unit - Google Patents

Abstract

The present invention relates to a method for repairing a scarfing unit for removing bubble defects or impurities generated on a surface of a slab in a steelworks slab correction process. More particularly, the present invention relates to a method for repairing a scarfing unit comprising the steps of: collecting used scarfing units, removing surface impurities of the used scarfing units, and disassembling the used scarfing units into parts; fusion-welding a restoration base material to a damaged part of the disassembled scarfing unit parts by using a brazing method; and cutting, polishing, and reassembling the brazed scarfing unit into the same form as a standard form of scarfing unit.

Description

Repair method for scarping unit "

More particularly, the present invention relates to a method for repairing a scarf unit that removes bubble defects or impurities generated on the surface of a slab in a steelworks slab correction process. More specifically, The brazed scarfing unit is then cut and polished in the same manner as the standard scarfing unit parts, and then the brazed scarfing unit is cut and polished The present invention relates to a scarfing unit repair method for reassembling.

In the manufacture and finishing of metal workpieces such as elongate steel slabs, billets and bar stocks, cracks (e.g., cracks) in rolling or casting processes bottom or side of the workpiece to remove surface defects such as cracks, seams, slag inclusions, surface oxides, and mechanical defects. And relative movement between the steel workpiece and the steel workpiece.

One type of known scarping device is an upper portion, a lower portion, and a lower portion disposed along the end portion and width of the workpiece to simultaneously scour each side of the workpiece through the scarfing device provided and through the scarfing devices. And an opposite side scarping unit.

In addition, the top, side, and bottom scarfing units of the scarfing device, respectively, are configured and arranged to receive and disperse both oxygen and fuel gas into a block assembly or opposing top and bottom preheat blocks provided as part of each such scarfing unit Gt; manifold < / RTI > and a head assembly.

Also, each of the upper and lower preheating blocks are spaced from each other to form an oxygen scarf therebetween, which allows the thermochemical scarping process to occur while the oxygen passes through the slots and heads toward the workpiece.

In addition, the lower preheating block typically maintains an oxidizing reaction on the surface of the workpiece and is subjected to an aspiration, i.e., to the oxygen flow for the purpose of shielding the oxygen flow from mixing with atmospheric air which reduces the effectiveness of the thermochemical scarping process. And a fuel gas passage having a discharge opening positioned adjacent to the oxygen slot formed by the upper and lower preheating blocks for discharging the fuel gas adjacent thereto.

That is, when the general scarifying unit having the above-described configuration is used for a certain period of time, solids are adhered to the surface of the scarifying unit, a part thereof is burned, and flow channels formed therein are damaged to flow oxygen, gas, The scarfing unit is repaired and reused because it is expensive.

The following is a representative prior art technique for repairing the scarping unit.

Korean Patent Registration No. 10-1492820 relates to a method of maintaining a sho-block of a scarfing device, comprising: a first step of removing foreign substances on a surface of a shoe block; A second step of removing the skid of the shoe block; A third step of mapping the surface of the shoe block; A fourth step of heat treating the surface of the shoe block; A fifth step of welding and growing the surface of the shoe block; A sixth step of uniformly machining a surface of the shoe block to form a skid insertion groove; A seventh step of chemically treating the shoe block; An eighth step of mounting a new skid in a skid insertion groove of the shoe block; A ninth step of inspecting the airtight state by supplying liquid or gas to the inside of the shoe block; And a tenth step of polishing the surface of the shoe block.

In addition, the shoe block maintenance method according to the related art realizes the effect of improving the efficiency of the scraping operation of the slab by replacing the damaged and deformed skid of the shoe block included in the scarping unit. However, There is a limit to how to repair parts of a damaged scarifying unit and to suggest a method for reusing the parts of the scarifying unit. Accordingly, there is a need for continuous research and development to solve the problem.

Korean Registered Patent No. 10-1492820 (Feb. Korean Registered Patent No. 10-1478531 (December 26, 2014) Korean Patent Registration No. 00-1478532 (Dec. 26, 2014)

The present invention relates to a scarfing unit repairing method. The scarfing unit conventionally used is merely a visual discrimination. The scarfing unit determines whether the scarfing unit is to be repaired It is impossible to confirm the degree of damage of the flow path formed inside the scarifying unit and the degree of cracking of the internal part of the scarifying unit so that the determination as to whether or not the repair has been made can not be accurately determined and the durability of the scarifying unit is not ensured ;

Particularly, since the repair method of the scarifying unit is processed by a general welding method using a welding rod, the precision of the welding part is lowered, and the problem of oxygen and gas spraying using the scarifying unit that has been repaired is not smooth, And to provide a solution to this problem.

The present invention has been made to solve the above-

A sanding step of removing impurities on the surface of the scarifying unit; A disassembling step of disassembling each part of the scarifying unit subjected to the sanding process; A primary machining step of cutting off a burned portion of each part of the scarifying unit subjected to the decomposition process; A brazing jig step of inserting a filler between the burned portion of each component of the scarifying unit subjected to the primary machining process and the restoration base material and fixing the same using a jig; A brazing process for brazing each part of the scraping unit processed by the brazing jig; A secondary machining step of cutting and polishing each part of the brazing-processed scarifying unit in the same shape as the standard shape of each part; And a checking step of processing pressure inspection and leakage inspection using gas or water after assembling each part of the scarifying unit subjected to the secondary machining process.

The scarfing unit repairing method according to the present invention as described above disassembles the scarifying unit subjected to the sanding process in the disassembling process so that the mass of each component of the scarifying unit is compared with each component of the scarifying unit before being used, The repairability of the scarfing unit can be clearly confirmed and the durability of the repaired scarfing unit can be ensured. Effect can be obtained;

Since the restoration base material can be welded to the burned portion by the brazing method, it is possible to secure more excellent accuracy of the welded portion as compared with the repaired scarping unit by the general welding method using the welding rod, It is possible to obtain an effect that the injection of oxygen and gas used can be secured to a degree equivalent to that of a new product.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view showing a scarfing unit repaired by a scarfing unit repairing method according to a preferred embodiment of the present invention. Fig.
2 is a block diagram of a process sequence showing a process sequence of a scarifying unit repair method according to a preferred embodiment of the present invention.
3 is a block diagram of a process sequence showing a process sequence of a scarifying unit repairing method according to another preferred embodiment of the present invention.

The present invention relates to a method for repairing a scarifying unit for removing bubble defects or impurities generated on the surface of a slab in a steelworks slab correction process, comprising: a sanding step (S100) for removing impurities on the surface of the scarifying unit; A decomposition step (S200) of decomposing each component of the scarifying unit subjected to the sanding process (S100); A primary machining step (S300) of cutting the burned portion of each component of the scarifying unit subjected to the decomposition process (S200); A brazing jig step (S400) of inserting a filler between the burned portion of each component of the scarifying unit subjected to the primary machining process (S300) and the restoration base material and fixing the same using a jig; A brazing process (S500) for brazing each component of the scarifying unit processed in the brazing jig process (S400); A secondary machining step (S600) of cutting and polishing each part of the scarifying unit processed in the brazing step (S500) in the same shape as the standard shape of each part; (S700) for assembling the parts of the scarifying unit subjected to the secondary machining process (S600) and then performing a pressure inspection and a leakage inspection using gas or water (S700) ≪ / RTI >

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.

First, the scarifying unit, which is repaired by the repairing method according to the present invention, is connected to a scarifying unit to generate a flame by using oxygen and gas, and removes bubble defects or impurities generated on the surface of the slab by using the flame Device.

The scarping device may also be constituted by a general component for the scarping process and is provided with a plurality of scarfing units continuously aligned outside a certain portion of the scarfing slab, The entire slab surface moved in the longitudinal direction can be scarcely processed.

At this time, the scarping device includes an oxygen supply device and a gas supply device capable of supplying oxygen and gas to the scarifying unit, a cooling water supply device for supplying cooling water for cooling the scarring unit generating the flame, The cooling water recovery device for recovering the cooling water may further be included.

The oxygen supply device, the gas supply device, the cooling water supply device, and the cooling water recovery device may be those well known in the art.

The scarfing unit may be composed of various components and preferably includes a head block 10, an upper block 30 and a lower block 40 and a shoe block 50 as shown in FIG. 1, Each of the head block 10, the upper block 30 and the lower block 40 is configured to be divided into a plurality of blocks for improvement of its function and structural change, 10, an upper block 30, or a lower block 40, as shown in FIG.

A portion of the head block 10, the upper block 30 or the lower block 40 where the fastening relationship between the head block 10 and the lower block 40 is established is provided between the head block 10 and the upper block 30 The upper block 30 or the lower block 40 can be improved in function and structural change can be achieved by further including the upper block 20 and the upper block 20. [

Hereinafter, the present invention will be described in more detail with respect to the head block 10, the upper block 30, the lower block 40, and the upper base 20, which may be included in the scarping unit, The carping unit repair method will be described in detail as follows.

Specifically, the scarifying unit repairing method according to the present invention includes a sanding step S100, a decomposition step S200, a primary machining step S300, a brazing jig step S400, a brazing step S500, The secondary machine is composed of the process (S600) and the inspection process (S700).

That is, the sanding process (S100) is a process of removing impurities on the surface of the scarfing unit. The sanding process (S100) removes impurities adhering to the surface of the scarfing unit, And the scarfing unit surface can be visually checked for a burned state.

At this time, the sanding step (S100) may be performed using a polishing machine equipped with a polishing pad, or may be performed by a sand blasting method in which sand particles (sand) having particulate property are sprayed by compressed air.

The decomposition process (S200) is a process of disassembling the components of the scarifying unit subjected to the sanding process (S100). The decomposition process (S200) includes the steps of: , The lower block (40) and the upper base (20).

That is, the scarping unit disassembled in the disassembling process (S200) can be divided into parts such as the head block 10, the upper block 30, the lower block 40 and the upper base 20, The processes after the decomposition process (S200) are separately processed so that the respective components are repaired.

In addition, each of the parts disassembled in the disassembling process (S200) may have different burnout degrees depending on the use environment of the scarfing unit, and the parts having a high degree of burnout may be discarded without processing the repair processes after the disassembling process (S200) Can be disposed of and recycled as a material for the manufacture of a new scarifying unit.

That is, since the parts of the scarifying unit are generally made of a copper material, the parts of the scarifying unit to be disposed of can be melted and then recycled as a melt for manufacturing a new scarifying unit.

At this time, a person skilled in the art can appropriately set a classification criterion of scaping unit parts classified as repair or disposal after the disassembling process (S200). However, in one embodiment, the mass of parts of the corresponding scarping unit And comparing the masses of the corresponding scarcings unit parts that have been disassembled.

More specifically, in general, the scarfing unit has a state exposed to high temperature and continuously flows oxygen, gas, and cooling water through the oxygen flow path, the gas flow path, and the cooling water flow path formed therein. The outer portions are burned off by the impurities of the components, and the flow paths are worn out, so that a portion of the flow path is lost or worn. As a result, the mass of each component becomes smaller than the mass of components before being used.

On the other hand, in the present invention, the mass of each component of the scarifying unit subjected to the decomposition process (S200) is compared with the mass of each component before being used, so that the weight loss is much larger than the weight before use of each component of the scarifying unit It is possible to process the following primary machining step (S300) for only the non-scarcing unit parts.

That is, since a significant amount of impurities are adhered to the surface of the scarifying unit before the sanding process (S100), when the mass of the used scarping unit is compared with the mass of the scarping unit before being used, The mass loss of the actually used scarping unit can not be precisely known due to the mass of the impurities; Since the scaping unit prior to the decomposition process (S200) is also in a state where a plurality of components are coupled to each other, if the mass loss of the entire scarfing unit is insufficient even if only the degree of burnout of only the specific scarfing unit component is large, It is difficult to process the following primary machining process (S300). Therefore, after the decomposition process (S200) in which impurities are removed from the surface of each component and decomposed, the repair target scarfing unit and the waste scouting unit .

Further, the comparison between the mass of each component of the scarifying unit subjected to the decomposition process (S200) and the mass of each component of the scarifying unit before use may be appropriately selected according to the judgment of a person skilled in the art, I will not.

Further, the primary machining step (S300) is a process of cutting the burned portion of each component of the scarifying unit subjected to the decomposition process (S200), wherein the portion corresponding to the outside of each component of the scarping unit, The gas passage, or the cooling water passage formed in the step (b).

That is, the primary machining step (S300) is a preprocessing process for removing the burned portions of each part of the scarifying unit from each part and newly restoring the burned part in the brazing step (S500).

At this time, the primary machining step (S300) may be performed using an appropriate cutting tool such as a cutter, a grinder, a drill, or the like according to a burned portion of each part of the scarfing unit. In one embodiment, In the case where the inner diameter of the gas passage, the cooling water passage, or the like is enlarged or a section is partially burned, the inner surface of the oil passage can be cut using a cutting tool such as a drill.

In addition, the brazing jig process (S400) is a process of inserting a fugitive material between a burned portion of each component of the scarifying unit subjected to the primary machining process (S300) and the restoration base member, This is a step of fixing the restoration base material having the shape before burning to the burned portion of each part of the scorped unit which is burned together with the fusing material.

That is, in the brazing-jig step (S400), the scraped surface of the scarfing unit, which has been processed in the primary machining step (S300), is sequentially laminated with the fleck material and the restoration base material, It is a process to fix the refractory material and the restoration base material with a jig so that it can be fixed to the cut-out portion.

At this time, the restoration base material is processed to have the same shape as the standard shape (production form) of each part before use, and has a different shape depending on the burned part of each part of the scarping unit, It is made of the same material as each part.

In one embodiment, if the outer part of the scarfing unit part is burned, the restoration base material is fixed to the burned part using the restoration base material having the same or larger state as the outer part, If a part of the flow path of the scarfing unit part is a burned part, it can be fixed to the burned part of the flow path by using a restoration base material which can block the burned flow path or form an internal part of the flow path.

The scarifier may be made of a suitable material depending on the material of each part of the scarifying unit, and each part of the scarring unit to be repaired may be made of copper The above-mentioned excipient may be composed of a material containing silver (Ag).

If the scaffold unit is made of copper and the filler material of the brazing jig process (S400) is made of silver (Ag), the silver material is excellent in thermal conductivity, It is possible to reduce the temperature difference between the burned material heated by the heat and the burned portion of each part of the scarifying unit and the restoration base material in the step (S500), and as a result, the physical properties of the welded portion can be improved.

In addition, since the melting point of silver is higher than that of a lead-based filler used in a general welding method, the use of a silver-based filler improves the heat resistance against the high heat applied in the brazing process (S500) It is possible to obtain an effect that the durability of the welded portion is improved and as a result the tensile strength of the repair portion of each part of the scarifying unit that is repaired can be improved.

It will be appreciated that the jig used in the brazing jig process (S400) can be of any appropriate shape depending on the shape of the respective parts of the scarring unit to be repaired or the position and shape of the burned part.

Further, the brazing process S500 is a process of brazing each component of the scarifying unit subjected to the brazing jig process (S400). The brazing process S500 is a process of brazing the components of the scarifying unit, Process.

That is, in the brazing process (S500), each component of the scarifying unit processed in the Brazing Jig process (S400) is received in a brazing furnace capable of applying a predetermined heat, and then heat-treated for a predetermined time, This is a process in which the component is not dissolved but the sparkling material is melted and the restoration base material is fused to the burned portion of each component of the scarifying unit.

If the components of the scarifying unit to be repaired are made of a copper material, various types of metal materials can be used as long as they have a melting point of 450 DEG C or higher, preferably silver (Ag) An alloy containing silver (Ag) as a main component may be used.

More preferably, when each component of the scarifying unit is made of a copper material, and when the scarifier is made of a silver material, the heating temperature of the brazing furnace is treated at a temperature of 700 to 1,050 ° C., The brazing process (S500) using the brazing furnace may be performed for 2 to 12 hours to bond the restoration base material to the burned portions of the respective parts of the scarifying unit.

In addition, the brazing may be preheated for 1 to 3 hours before being heated to 700 to 1,050 ° C., and may be preheated for 3 to 5 hours after being heated for 2 to 12 hours within a temperature range of 700 to 1,050 ° C. The cooling process can be done with brazing.

That is, the brazing process (S500) as described above is restored to the damaged portion of each part of the scarifying unit without deteriorating the deformability and physical properties of each part of the scarifying unit and the repairing base material, It is possible to realize an effect that the base material can be fused and an effect that the fused portion can be precisely bonded can be realized.

Further, the brazing of the brazing step S500 may be controlled by a specific pressure or may be in a vacuum state to increase the efficiency of the brazing step S500. The vacuum pressure of the brazing furnace may be appropriately adjusted according to the judgment of a person skilled in the art have.

In addition, the secondary machining step S600 is a step of cutting and polishing each part of the scarifying unit processed in the brazing step S500 in the same shape as the standard shape of each part, And a step of cutting and polishing the surface of the restoration base material and the fused portion of the scarfing unit.

That is, the secondary machining step S600 may be performed in the same manner as the standard shape of each part of the scarifying unit before the first use of the cooled scarfing unit after the brazing process (S500) As a process of machining, it can be processed with a suitable cutting tool such as a cutter, a grinder, a drill or the like.

In one embodiment, the restoration portion of each component of the scarifying unit is a flow path for flowing oxygen, gas, or cooling water. In the brazing jig process (S400), after the restoration base material is inserted into the flow path, S500, the worker uses a cutting tool, such as a drill having an outer diameter equal to the inner diameter of the standard type flow path, to connect the flow path having the same inner diameter as the standard flow path to the restoring portion As shown in FIG.

The inspection process (S700) is a process of processing pressure inspection and leakage inspection using gas or water after assembling the parts of the scarifying unit processed in the secondary machining process (S600), wherein the secondary machine And assembling each part of the scarifying unit in which the burned part is restored through the machining step (S600) to make a scarfing unit, and then, it is confirmed whether the complete repair has been performed.

At this time, the restored and reassembled scarfing unit can use a fluid such as gas or water instead of oxygen, gas and cooling water to confirm the flow state of oxygen, gas and cooling water.

Particularly, in the inspection process (S700), the injection state of the oxygen and gas injected after flowing through the oxygen flow path and the gas flow path is checked, and the pressure of the oxygen and the gas It is necessary to check whether the restoration portion is damaged again if it is applied and to check whether the oxygen, gas or cooling water leakage occurs at the joint portion of each part of the assembled scarping unit, And leakage inspection.

In connection with the above, the present invention processes a cleaning process for cleaning each part of the scarfing unit processed in the secondary machining process (S600), and performs a cleaning process for cleaning each part of the scarfing unit processed in the secondary machining process (S600) The foreign matter adhering to the surface and the flow path of the gas can be removed.

That is, the cleaning process may be performed in various ways according to the judgment of a person skilled in the art, and preferably, the process may be performed by an ultrasonic cleaning process (S650) for removing foreign matter by using an ultrasonic cleaning device.

At this time, since the ultrasonic cleaning step S650 can remove foreign substances on the surfaces and the flow paths of the parts of the scarifying unit processed by the secondary machining process (S600) using ultrasonic waves, It is possible to minimize the damage of each part of the scarifying unit that has been repaired due to the physical force.

In addition, each component of the scarifying unit processed in the ultrasonic cleaning process S650 as described above can be completed in the scarifying unit repair process according to the present invention by processing the inspection process S700.

The following is a preferred embodiment of repairing the scarifying unit by the scarping unit repairing method according to the present invention.

1. Sanding Process

The scaffolding unit used in the steelworks is dressed and sand blasted with sand to remove impurities adhering to the surface of the scarifying unit.

2. Decomposition Process

The scalloping unit of the sanding-fixed copper material is disassembled and separated into parts such as a head block, an upper block and a lower block and a shoe block.

3. Primary Machining Process

The burned portion of each of the parts subjected to the decomposition process is cut using a cutting tool.

4. Brazing jig process

(Ag) material is inserted between the cutting face of each part of the scarifying unit subjected to the primary machining process and the restoration base material (original state of the part in the initial design), and then the scarfing unit And the restoration base material is fixed on the cutting surface of each part of FIG.

5. Brazing process

The brazing furnace preheated at a temperature of 400 DEG C was operated at a temperature of 1,000 DEG C for 6 hours and the brazing furnace was cooled to cool each part of the scarifying unit And the restoration base material is fused to the burned portion.

6. Second Machining Process

After naturally cooling each part of the brazing-processed scarifying unit, each part of the cooled scarifying unit is cut and polished in the same shape as the standard shape of each part.

7. Ultrasonic Cleaning Process

Each part of the scarifying unit subjected to the secondary machining process is inserted into the ultrasonic cleaner, and ultrasonic waves are applied to remove foreign substances on the surfaces and the flow paths of the respective parts of the scarifying unit.

8. Inspection process

After assembling the parts of the scarifying unit subjected to the ultrasonic cleaning process, water is supplied to the oxygen flow path, the gas flow path and the cooling water flow path, respectively, to perform pressure inspection and leakage inspection.

At this time, the water supplied to the oxygen flow path, the gas flow path and the cooling water flow path is processed by the pressure of the same condition as when the actual scarping unit is mounted on the scarfing device, and flows through the oxygen flow path and the gas flow path, Check the spraying state of the water, and check whether the water is leaked through the joint part and the restoration part of each part of the scarifying unit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It is possible to carry out various changes in the present invention.

10: head block 20: upper base
30: upper block 40: lower block
50: Shublock
S100: Sanding process S200: Decomposition process
S300: primary machining step S400: brazing jig process
S500: Brazing process S600: Secondary machining process
S650: Ultrasonic cleaning process S700: Inspection process

Claims (4)

A sanding step (S100) for removing impurities on the surface of the scarifying unit;
A decomposition step (S200) of decomposing each component of the scarifying unit subjected to the sanding process (S100);
A primary machining step (S300) of cutting the burned portion of each component of the scarifying unit subjected to the decomposition process (S200);
A brazing jig step (S400) of inserting a filler between the burned portion of each component of the scarifying unit subjected to the primary machining process (S300) and the restoration base material and fixing the same using a jig;
A brazing process (S500) for brazing each component of the scarifying unit processed in the brazing jig process (S400);
A secondary machining step (S600) of cutting and polishing each part of the scarifying unit processed in the brazing step (S500) in the same shape as the standard shape of each part;
(S700) of assembling each part of the scarifying unit processed in the secondary machining step (S600) and then performing a pressure inspection and a leakage inspection using gas or water (S700) Scorping unit repair method.
The method according to claim 1,
Wherein each part of the scarfing unit is made of a copper material,
Wherein the scaffold of the brazing jig step (S400) is made of a material containing silver (Ag).
3. The method of claim 2,
The brazing process (S500)
Wherein the brazing jig process (S400) is configured to treat each component of the scarifying unit in a brazing furnace at a temperature of 700 to 1,050 占 폚 for 2 to 12 hours.
The method according to claim 1,
Each part of the scarifying unit processed in the secondary machining step (S600)
Wherein the ultrasonic cleaning process (S650) for removing the foreign substance by using the ultrasonic cleaning device is further performed and then the inspection process (S700) is performed.

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