KR20030054973A - Method for manufacturing the wire rod coil and apparatus for descaling the oxide scale of wire rods - Google Patents

Abstract

PURPOSE: A method for manufacturing wire rod coil and an apparatus for removing oxide film are provided to prevent environmental pollution according to pickling, increase efficiency of overall manufacturing process, improve productivity and remove oxide film more economically. CONSTITUTION: In an apparatus for removing oxide film formed on the surface of wire rod, the apparatus for removing oxide film comprises an uncoiler(90) for releasing wire rod coil so that the released wire rod coil is continuously supplied in a direction; a pre-straining die(110) arranged at the output side of the uncoiler(90) to apply strain to outer diameter of the wire rod transferred; a descaling chamber(120) on which a plural nozzles(121) are mounted in a wire rod length direction to remove oxide film on the surface of the wire rod, wherein the plural nozzles(121) spray ultra-high pressure water onto the surface of the wire rod entered into the descaling chamber(120) after passing through the pre-straining die(110); and a dryer(130) arranged at the input side of wire drawing machine(9) to dry the wire rod the oxide film formed on the surface of which is removed in the descaling chamber(120), wherein the pre-straining die(110) comprises a wire drawing die installed in such a way that the wire drawing die seals a wire rod entrance of the descaling chamber(120) and reduces outer diameter of the wire rod released from the uncoiler(90) as much as about 0.5 to 5%, wherein a support roller(122) is installed in the inner space of the descaling chamber(120) to prevent vibration during transferring of the wire rod moved in a direction and constantly maintain a gap between the nozzles(121) and wire rod, and wherein a wire drawing die type sealing die(129) for reducing outer diameter of the wire rod as much as less than 1% and applying strain to the outer diameter reduced wire rod so that a wire rod entrance of the chamber(120) through which the wire rod passes is sealed is installed between the descaling chamber(120) and dryer(130).

Description

Wire Rod Coil Manufacturing Method and Oxide Film Removal Equipment TECHNICAL FOR MANUFACTURING THE WIRE ROD COIL AND APPARATUS FOR DESCALING THE OXIDE SCALE OF WIRE RODS}

The present invention relates to a method and an apparatus for removing an oxide film in a process of manufacturing a small diameter wire drawn material using a hot rolled hot wire material, and more particularly, to increase the mechanical peelability of the oxide film during the production of the hot drawn wire material. After the phase transformation is completed in the cooling zone, the hot-cooled wire rod is manufactured by rapid cooling. Then, it is passed through the straining die, and the oxide layer on the surface is cracked. The oxide layer is removed using ultra-high pressure water, and then dried and wound up. Or wired directly to a fresh facility to prevent problems such as environmental pollution due to pickling, improve the efficiency of the overall manufacturing process, improve productivity, and significantly improve the cost of removing oxide film more economically. It relates to a coil manufacturing method and an oxide film removing device.

In general, the process of manufacturing a steel wire that is a base material of the drawing process is the upper and lower rolls (1a) is a continuous hot ball rolling mill (1) is heated (bloom) or billet (billet) as shown in FIG. The wire rod is gradually rolled to a predetermined diameter while passing through), and the wire rod of 1000 to 1100 ° C. that is rolled while passing through the ball mill 1 is continuously passed through the water cooling stand 2 to a predetermined temperature of about 700 to 900 ° C. After cooling to temperature, it is passed through a laying head 3 to form a loose coil.

Subsequently, the coil-shaped wire rod is slowly cooled by passing through the conveyor-shaped cooling table 4 or cooled to an appropriate temperature by compressed air, and then wound by a coil of coil type in the winder 5. It is manufactured through a series of continuous processes.

The surface of the high-temperature wire manufactured during such hot rolling and cooling processes is combined with oxygen in the air to form a dense oxide film having a thickness of several μm to several tens of μm.

On the other hand, the secondary process of processing the wire rod rolled in the hot wire with a small diameter as a base material is called a drawing process, as shown in Figure 2, by uncoiler 8 to unwind the wire coil to the drawing machine (9) After supplying, normally, the method of drawing by continuously passing the wire rod supplied from the said uncoiler 8 through the drawing machine 9 in which the die of a small diameter was built | induced is used at normal temperature.

In order to prevent the surface quality of the final product and the wear of the die installed in the drawing machine 9 in performing the wire drawing process, the oxide film generated on the surface of the wire rod, which is the base material, is removed and a lubricant is applied to the drawing machine (9). Must pass through the die. A method of removing an oxide film of a conventional wire rod for this purpose is mainly used by pickling method, which is a wire coil wound in a pickling tank 6 filled with a strong acidic solution such as nitric acid or hydrochloric acid. The oxide film is chemically peeled off by depositing the bundle and maintained for a predetermined time, and then, the wire rod bundle in which the oxide film has been peeled off is deposited in a water washing tank 7 filled with a predetermined amount of water, and the separated oxide film is washed with water and dried.

However, the above-described chemical pickling method requires a long time because the pickling process in the pickling tank 6 is a relatively slow reaction, and the air is contaminated by the pickling solution evaporated from the pickling tank 6 so as to deteriorate the surrounding operating environment. On the other hand, there were many problems due to the corrosion of the peripheral equipment. In addition, water pollution problems and increased production costs due to the continuous generation of waste acid are inevitable.

In addition, since the deposition time over a long time is required in the pickling tank 6 and the washing tank 7, the continuous operation of the coil bundle unit must be performed, thus acting as a big obstacle to the sequencing and automation of the drawing process.

On the other hand, various techniques have been proposed to improve the problems caused by chemical pickling as described above. For example, a method of peeling an oxide film by an electrolysis method using a neutral solution, and by installing a rolling mill in front of a pickling bath Some methods have been employed to improve pickling properties by adding strain reduction or adding strain to the surface by installing a leveler-type scale breaker, or by crushing the oxide film by shot blasting. There was a problem that the equipment is not complicated.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problems, in the drawing process including the step of manufacturing the steel wire and the step of removing the oxide film formed on the surface during hot rolling, in the cooling process after hot rolling of the wire A base material with excellent peelability is secured by securing an appropriate cooling rate, and a small amount of deformation is added while releasing the wire coil in place of the conventional pickling method for removing the oxide film before the drawing process to induce cracking of the oxide film and then continuously. By spraying ultra-high pressure water on the surface of the wire rod to remove the oxide film, it is possible to solve various problems such as environmental pollution due to chemical pickling, to improve the efficiency of the overall manufacturing process, and to improve the work productivity as well as more economically. Provided is a wire coil manufacturing method and an oxide film removing device by removing the oxide film. There is a purpose.

1 is a schematic view showing a manufacturing process of a conventional hot rolled wire coil,

2 is a schematic diagram showing a conventional oxide film removing process and a drawing process;

3 is a schematic view showing an example of a wire coil oxide film removing process of the present invention;

4 is a schematic view showing an example of a nozzle arrangement for removing an oxide film from a wire surface

5 is a schematic view showing the distance between the nozzle and the support roller, the spray angle and the nozzle and the material of the oxide film removing device according to the present invention,

Explanation of symbols on the main parts of the drawings

1 ..... rolling mill 2 ..... water cooler

3 ..... laying head 100 .... oxide removal device

110 .... prestraining die 120 .... descaling chamber

121 .... Nozzles 122 .... Support Rollers

129 .... Sealing die 130 .... Dryer

As a technical configuration for achieving the above object, the present invention,

Cooling in the cooling zone of the conveyor to improve the mechanical peelability of the iron oxide film formed on the surface of the high temperature wire rod in which phase transformation is completed after hot rolling;

Supplying the uncoiled wire rod from the wire coil wound up after being quenched into the descaling chamber to remove the oxide film on the wire rod surface as ultra high pressure water;

And feeding the wire rod from which the oxide film is removed from the descaling chamber into a dryer to dry the wire rod as a heat source, and then supplying the wire rod into a drawing machine to reduce the outer diameter of the dried wire rod. By providing an oxide film removing device.

Hereinafter, the present invention will be described in more detail.

The characteristics of the present invention will be described in more detail by dividing the cooling process after hot rolling and the oxide film removing process before the drawing process.

<Cooling method after hot rolling to improve peelability of oxide film>

In a typical wire rod rolling process, the cooling process is carried out by passing a high temperature wire rod, which has been rolled at about 1000 to 1100 ° C., through a water cooling stand 2, and quenching it at a temperature of about 900 to 600 ° C., followed by a loose coil. The roller is moved on the table and gradually cooled to induce phase transformation. The cooling rate at this time determines the material and microstructure of the product, so it is strictly managed by steel type and diameter.

In general, the effect of the cooling rate after the end of the phase transformation on the material is known to be insignificant, but greatly affects the peelability of the oxide film. Therefore, after the phase transformation is completed, the wire rod properly manages the cooling rate, thereby greatly improving the mechanical peelability of the oxide film.

That is, the surface of the wire rod during hot rolling and air-cooling combines with oxygen in the air to form an oxide film, which is mainly wistite (FeO). When the material is slowly cooled by the natural air cooling method, the thickness of the oxide film is gradually increased by being combined with oxygen in the air while being maintained for a relatively long time at a high temperature. magnetite, Fe3O4) and hematite (hematite, Fe2O3) will be transformed.

At this time, the bonding force between the oxide film and the base metal is increased during the phase transformation process of the oxide film, and the magnetite and hematite, which are transformed phases, have a dense structure and a high breakdown strength compared to the visite, which is a high temperature phase. Therefore, it is well known that pickling properties increase when the cooling rate is increased by spraying compressed air instead of natural air cooling.

While designing the present invention, such a rapid cooling method was found to have a great effect not only on pickling but also on mechanical oxide removal using high pressure water. In the case of rapid cooling, there is no increase in the thickness of the oxide film, and it suppresses the transformation into magnetite and hematite, thereby improving the peelability of the oxide film in the subsequent oxide film removing process, and the surface increases as the cooling rate increases. Oxide film is preferentially cooled and high temperature deviation occurs between the oxide film and the base metal, resulting in high tensile stress in the oxide film due to the difference in temperature and thermal expansion coefficient, resulting in many microcracks in the oxide film whose toughness is reduced by cooling. Therefore, such a microcrack acts as a factor to improve the peelability in the mechanical oxide film removal process.

The degree of growth inhibition of the oxide film, the degree of suppression of oxide phase transformation, and the occurrence of cracking are all dependent on the cooling rate, and the faster the cooling rate, the better the oxide film peelability. It is desirable to obtain a cooling rate of 5 ° C / sec or more.

Here, the temperature and the appropriate cooling rate to start the quench should consider not only the aspect of the oxide film peelability improvement but also the phase transformation behavior.

In the case of general low carbon steel wire rod, most of the phase transformation is completed at the initial stage of cooling, so that when the temperature is about 600 ° C. or less, there is no significant change in the material even when quenching. In addition, steels without phase transformation during cooling, such as stainless steels, do not change significantly even when quenched.

However, in the case of a material having a large hardenability due to the addition of a large amount of alloying elements, such as high carbon steel or high alloy steel, phase transformation may not be finished even if it is slowly cooled to about 600 ° C. In this case, in the case of rapid cooling, unchanged austenite is transformed into bainite or martensite, so that the material change such as the strength is greatly increased and the elongation is decreased, and thus the target material cannot be obtained. Therefore, in this case, it is preferable to perform quenching after the phase transformation is completely completed in consideration of the phase transformation behavior according to the cooling rate.

<Oxide removal process>

As described above, the hot rolled wire rod cooled by rapid cooling is completely removed by using the oxide film removing apparatus 100 according to the present invention, and then introduced into a drawing process.

The oxide film removing apparatus 100 of the present invention forms microcracks on the oxide film generated on the surface of the wire by adding a predetermined deformation to the wire that is continuously released from the uncoiler 90 and is conveyed in one direction. By completely removing the oxide film that is forcibly cracked by using, the apparatus 100 is the uncoiler 90 to unwind the wire coil and continuously supply in one direction, and the wire of the wire rod is disposed on the exit side of the uncoiler 90 A plurality of nozzles for spraying ultra-high pressure water to the surface of the pre-straining die (110) for adding a deformation to the outer diameter and the wire rod which is disposed on the exit side of the pre-straining die (110) and flows through the pre-straining die (110) A descaling chamber 120 for removing the oxide film on the surface of the wire rod by mounting a plurality of 121 in the wire length direction, and a wire in which the oxide film is removed from the descaling chamber 120. To dry the dryer consists of 130, which is disposed in the inlet of sinseongi 9. The winding machine 9 may be provided on the outlet side of the drawing machine 9 to wind a wire rod having a reduced outer diameter with a coil in the state where the oxide film is removed.

As described above, the method of peeling the oxide film formed on the wire rod surface running in one direction from the inside of the descaling chamber 120 as the high pressure water is used to remove the oxide film generated in the heating furnace during the normal hot rolling process or just before rolling. It is a technique used to install a descaler to descale using a high pressure water spray to remove the. In this case, the oxide film is relatively thick, porous, and thermal shock due to quenching acts in addition to the mechanical impact caused by high pressure water, so that the oxide film is easily removed even at a pressure of 300 bar or less.

However, at room temperature where hot rolling and cooling are completed, as in the case of the present invention, since the oxide film is relatively thin and dense, and there is no effect of thermal shock, the wire rod is applied under appropriate conditions only when spraying at least 1000 bar of ultra-high pressure water onto the wire surface. The oxide film on the surface can be pulverized and peeled off. At this time, the appropriate conditions depend on the properties of the oxide film, the pressure of the high pressure water, the flow rate per nozzle, the distance between the nozzle and the material, the high-pressure water collision angle, the conveying speed of the material.

That is, when the energy administered to the surface of the steel sheet by the ultra-high pressure water is greater than the bonding energy between the oxide film and the base metal, the oxide film can be easily peeled off, and when the administered energy is insufficient, the oxide film is not completely peeled off.

On the other hand, when the impact energy due to the ultra high pressure water is more than the binding energy, wire damage such as not only the oxide film formed on the wire surface but also the base metal may be formed.

Therefore, in the present invention, prestraining (pre-straining) immediately before the oxide film removal process using the ultra-high pressure water by installing a prestraining die 110 to change the outer diameter on the wire to be processed, the wire rod forcibly passing through By adding a predetermined outer diameter deformation to the surface of the surface, cracks are formed in the oxide film formed on the surface of the wire, and at the same time, work hardening is induced on the surface metal layer so that the base metal is not damaged even by ultra high pressure water.

Here, the pre-straining die 110 may use a conventional drawing die as it is, and the drawing through the diameter reduction is not intended, but the crack in the surface oxide film layer at the entrance side of the descaling chamber 120 and the surface layer portion of the base metal Since the purpose is to harden the process, it is preferable to have a draw hole having a diameter size of about 0.5 to 5% of the diameter reduction reduction with respect to the wire rod outer diameter supplied from the uncoiler (90). Of course, as the amount of deformation of the wire rod outer diameter passing through the prestraining die 110 increases, it is advantageous to the exfoliation of the oxide film, but wear of the prestraining die may increase because the lubricant is not applied.

The prestraining die 110 is coupled to the inlet side of the front surface of the descaling chamber 120 to add deformation to the surface of the wire material to create a crack in the oxide film and at the same time the external air through the inlet through which the wire is supplied. It serves to seal the inlet of the chamber 120 from the outside to block the inflow. In addition, since the outer diameter of the wire rod material at the entrance side to be operated may vary, the prestressing die 110 may be installed to be easily replaced at the entrance side front surface of the descaling chamber 120.

In addition, a nozzle 121 for injecting a high pressure stream of water to the outer surface of the wire rod that proceeds in one direction is transferred to the inner space of the descaling chamber 120 that is installed in succession to the prestraining die 11. A high pressure water pump for preventing vibration and making the water flow injected from the nozzle 121 and a support roller 122 for maintaining a constant gap between the nozzle 121 and the wire 121 123) and the like, wherein the chamber 120 has a rectangular box shape having inlets and outlets through which wires are drawn in and drawn out to prevent the scattering of ultra-high pressure water that strikes them so as to remove the oxide film formed on the wire surface. It is composed of, the bottom of the funnel-shaped collection tank is installed to discharge the residual water and oxide film residue.

The descaling chamber 20 has an ultra high pressure jet nozzle 121 and a support roller 122 arranged on the basis of a pass line of the wire rod passing through the prestraining die 110. , The arranging method is arranged in a spiral or zigzag at a distance such that the ultra-high pressure water injected from each nozzle 121 does not interfere with each other.

The nozzle 121 and the support roller 123 are installed in a sufficient number of at least three or more tanks so that the ultra-high pressure water sprayed from the nozzle 121 can cover the entire surface area of the wire rod, and at this time, each nozzle 121 is It is preferable to stagger each other in order to prevent interference with each other.

4 illustrates an example in which four nozzles of the fan type are alternately disposed at 90 ° intervals as an example of a preferred nozzle arrangement. Each nozzle 121 is connected to the high pressure water supply pipe 124, and the high pressure water supply pipe ( 124 is connected to the high pressure water pump 123 for generating ultra high pressure water.

Here, the nozzle 121 may use a full cone type fan and a fan type fan that spread in a conical shape.

Since the orifice of the nozzle 121 is a portion where the ultra-high pressure water of 1,000 bar or more is discharged at a supersonic speed for a long time, it is preferable to use a high-wear-resistant synthetic sapphire or synthetic diamond so as not to wear even when spraying high-pressure water for a long time.

The discharge pressure, the shape of the water flow, the spray angle of the nozzle, and the length of the water flow, that is, the distance between the nozzle and the material, determine the energy density, which is an important parameter in the oxide film peeling process.

If the nozzle angle θ of the nozzle 121 is large and the distance L between the nozzle 121 and the wire rod is long, it is advantageous to widen the collision area per nozzle 121, but if they are too large, the energy density per unit area Since decreases, the oxide film peeling ability is reduced.

The spray angle θ of each nozzle should be selected in consideration of the distance L between the installed nozzle 121 and the wire rod and the diameter d of the wire rod material to be worked on.

As shown in FIG. 5, when the distance between the wire center of the wire diameter d and the nozzle 121 is L, the maximum spray angle θ effective for peeling the oxide film is expressed by the following equation [1]. If the above angle is given, waste of energy occurs.

In addition, when the injection angle (θ) and the wire diameter (d) is determined, the optimum effective distance (L) between the material center and the nozzle tip is expressed by the following equation [2].

With regard to such a geometric nozzle shape and arrangement, the most important factor in removing the oxide film is the effective energy that acts to exfoliate the oxide film on the wire surface.

That is, when the effective energy is added above a certain upper limit value, not only oxide film removal but also damage of the base metal occurs, and when it is added below a certain lower limit value, the removal of the oxide film does not occur completely. When the number is added to the wire surface, it is possible to obtain a desirable surface property in which the oxide film is completely removed.

When the collision energy transmitted to the wire rod by the high pressure water discharged from one nozzle per unit time is e, the collision energy (e) is equal to the discharge pressure (P) of the high pressure water and the flow rate (Q) per nozzle as shown in Equation 3 below. Is represented by.

e = P Q

At this time, the area A in which the high pressure water collides per unit time is determined by the distance L between the nozzle and the wire rod, the injection angle θ, and the material feed rate v, which is represented by Equation 4 below.

A = πd v (180-θ) / 360

Therefore, when the energy density value transmitted per unit area of the wire rod from the nozzle is E, it is expressed by the following equation (5).

E = e / A = PQ / [πd v (180-θ) / 360]

After hot-rolled wire rods are quenched at a rate of 5 ° C./sec or more, as in the method of the present invention, they are passed through a prestraining die 110 to add 1 to 3% of a strain reduction, and then an oxide film is peeled off. The range of the appropriate energy density value (E) was presented as shown in Equation 6 below.

1,000 (kJ / m2) ≤ E ≤ 8,000 (kJ / m2)

Therefore, the energy density value determined by the pressure and flow rate of the high-pressure water pump 123, the spray angle of the nozzle, the distance between the material and the nozzle, and the conveying speed of the material based on the above-described energy density estimation equation and range are described above. By constructing the equipment to satisfy the range, satisfactory surface properties from which the oxide film is removed can be obtained.

In addition, it can be seen that in order to increase the feed rate for determining productivity from the above equation, it is necessary to increase the pressure and flow rate in proportion to this, or to reduce the distance L between the nozzle 121 and the material. However, when reducing the distance (L) between the nozzle 121 and the wire rod, the cross-sectional area in which one nozzle 121 can peel the oxide film is reduced, so the number of nozzles in the circumferential direction should be increased in proportion to this.

After the above-described process, the wire rod in which the oxide film is separated in the descaling chamber 120 passes through the sealing die 129 installed at the exit side of the chamber 120 and is subsequently installed to remove residual moisture from the surface. It is dried while passing through the dryer (130).

Sealing die 120 is installed between the chamber 120 and the dryer 130 is to reduce the wire outer diameter passing through the chamber 120 to a small amount of less than 1% by using a facility in the form of a drawing die. It is desirable to add strain to achieve a complete seal to the outlet of the chamber 120.

And, the dryer 130 is possible by a drying method such as a normal hot air or high-pressure air injection, by blowing high-pressure air to the wire rod side using a high-pressure air nozzle to blow out residual oxide film residues that may be buried on the surface desirable.

Hereinafter, the present invention will be described in more detail with reference to Examples.

<Example>

In the present embodiment, the low carbon steel containing 0.07% carbon, which is a representative material used for drawing, is finish-rolled at a rolling mill 1 at 1050 ° C. with a diameter of 5.5 mm, and then cooled at 800 ° C. by cooling with water in the water cooling stand 2. After the phase transformation was completed via the laying head 3, compressed air was blown and rapidly cooled to 200 ° C or lower at a rate of 20 ° C / sec, and then wound up in the winder 5.

The wire coil wound as described above is passed through the prestraining die 110 having an inner diameter of 5.4 mm to give a reduction of about 1.8%, and then enters into the descaling chamber 120 and passes through a nozzle installed therein. Ultra high pressure water was injected from (121) to investigate the degree of oxide film removal.

At this time, the discharge pressure of the high-pressure water for removing the oxide film is 2,000 bar, the oxide film at a speed of 10m per minute using a facility equipped with a fan-type nozzle with a flow rate of 2liter / min per nozzle, the injection angle (θ) of 20 ° Removal was carried out. In this case, the distance L between the nozzle 121 and the wire center is adjusted to be 15.8 mm using Equation 2.

Under these conditions, the theoretical energy density administered by one nozzle 121 per unit area is calculated based on [Equation 5] to be 5210.9 kJ / m 2, which satisfies the above-mentioned proper energy density range. Can be.

When the oxide film was removed under such conditions and facilities, a good surface from which the oxide film was completely removed was obtained. The result was freshly drawn to a small diameter of 0.5 mm through the drawing process. Could be manufactured.

According to the present invention as described above, first, the chemical pickling process requires a long time chemical reaction and is intermittently performed, while omitting the pickling process through the method of the present invention and improving the logistics flow by continuous line with the fresh equipment. It can shorten the inventory cost for pickling period, shorten the delivery time for the demand of new wires,

Second, through rapid quenching, micro cracks are formed on the surface oxide film and the oxide film growth is suppressed, while * phase transformation of the oxide film to magnetite and hematite is suppressed, thereby greatly improving the peelability of the oxide film, and improving the surface quality.

Third, by manufacturing the steel strip from which the oxide film is removed by the method of mechanically peeling the oxide film using ultra-high pressure water, it is possible to improve all environmental problems such as air pollution and equipment corrosion by the conventional chemical pickling method. .

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Claims (10)

Cooling in the cooling zone of the conveyor to improve the mechanical peelability of the iron oxide film formed on the surface of the high temperature wire rod in which phase transformation is completed after hot rolling; Supplying the uncoiled wire rod from the wire coil wound up after being quenched into the descaling chamber to remove the oxide film on the wire rod surface as ultra high pressure water; And supplying the wire rod from which the oxide film is removed from the descaling chamber into a dryer to dry the wire rod as a heat source, and then supplying the wire rod into the drawing machine to reduce the outer diameter of the dried wire rod. The method according to claim 1, wherein the cooling step cools the wire rod after the end of phase transformation during hot rolling to 200 ° C or less, and a cooling rate of at least 5 ° C / sec or more. The wire rod of claim 1 or 2, wherein the wire rod is formed at the front inlet of the descaling chamber to improve the peelability of the oxide film and to seal the inlet of the descaling chamber before removing the oxide film in the descaling chamber. Wire coil manufacturing method characterized in that it further comprises the step of reducing the reduction in the range. The method of claim 1, wherein the step of removing the oxide film includes ultra-high pressure water of 1000 bar or more through the nozzle such that the effective energy density (E) of the ultra high pressure water obtained by Equation 1) is within a range of 1000 to 8000 (kJ / m 2). Spray on the wire surface to remove the oxide film, Equation 1) is E = PQ / {π d v (180-θ) / 360} Where E is the effective energy density, Q is the flow rate per nozzle, θ is the spray angle of the nozzle, d is the diameter of the wire for drawing, and v is the feeding speed of the wire. The method of any one of claims 1 to 4, further comprising reducing the wire rod to less than 1% at the rear exit of the descaling chamber to seal the outlet of the chamber after removing the oxide film in the descaling chamber. Wire coil manufacturing method characterized in that. In the apparatus for removing the oxide film formed on the surface of the wire rod, An uncoiler 90 that unwinds the wire coil and continuously supplies it in one direction; A pre-straining die (110) for adding deformation to an outer diameter of the wire rod which is disposed on the exit side of the uncoiler (90); A descaling chamber 120 mounted with a plurality of nozzles 121 in a wire length direction to spray ultra-high pressure water to the surface of the wire rod flowing through the prestraining die 110 to remove the oxide film on the wire rod surface; And And a dryer (130) disposed at the inlet side of the drawing machine (9) to dry the wire rod from which the oxide film has been removed in the descaling chamber (120). 7. The drawing die according to claim 6, wherein the prestraining die 110 reduces the wire rod outer diameter supplied from the uncoiler 90 to about 0.5 to 5% to seal the wire inlet of the descaling chamber 120. An oxide film removing device, characterized in that configured. 8. The oxide film removing apparatus according to claim 6 or 7, wherein the nozzles (121) are arranged in a spiral or zigzag at a distance such that the ultra-high pressure water sprayed therefrom does not interfere with each other. The support roller of claim 6, wherein an inner space of the descaling chamber 120 prevents vibration during transfer of the wire rod which is moved in one direction and maintains a constant distance between the nozzle 121 and the wire rod. Oxide film removing apparatus characterized in that the installation 122 According to claim 6, Between the descaling chamber 120 and the dryer 130 for wire drawing to reduce the wire outer diameter to less than 1% to add a strain to seal the wire exit of the chamber 120 through which the wire passes through Line removing film, characterized in that for installing the die-type sealing die (120).