KR20130064613A - Apparatus and method for treating surface of hot rolled strip - Google Patents

Abstract

PURPOSE: A device and a method for treating a surface of a steel sheet are provided to manage a surface roughness of a steel sheet by passing a steel sheet in which a scale is removed through a skin pass mill and a polishing brush unit. CONSTITUTION: A device for treating a surface of a steel sheet comprises a scale breaker(300), a slurry injection unit(400), a skin pass mill(700), and a polishing brush unit(800). The scale breaker is provided on a transfer path of a steel sheet. The slurry injection unit removes a scale in a downstream side of the scale breaker. The skin pass mill is provided to a downstream side of the slurry injection unit. The polishing brush unit is provided to a downstream side of the skin pass mill.

Description

Apparatus and method for treating surface of hot rolled strip}

The present invention relates to the surface treatment of steel sheets, in particular the steel sheet, which enables the removal of scale and the surface roughness management generated on the surface of the hot rolled steel sheet, and more particularly, the scale of the steel sheet, in particular hot rolled steel sheet, such as non-oriented electrical steel sheet It can be effectively removed through braking and slurry blasting, and in particular, the scaled steel sheet is passed through the skin pass mill and the polishing brush to realize the surface roughness management of the steel sheet. It relates to a surface treatment apparatus and method for hot-rolled steel sheet improved.

Hot-rolled steel sheets of carbon steel, high-strength steel, silicon-added steel for electric motors or stainless steel at high temperatures (particularly steel strips), in particular, the surface of non-oriented electrical steel sheets of 3.5% or less of hot-rolled Si at a high temperature of several to several tens of micrometers. A scale layer is created.

On the other hand, Figure 1 shows a facility for removing the scale generated on the surface of such a hot rolled steel sheet.

That is, as shown in FIG. 1, the pickling facility for removing a conventionally known scale generates a crack (cracks) on the scale of the steel sheet surface by using the scale breaker 10, and then pickling bath 40. ) And the scale was removed while passing through the washing tank (50) step by step.

Although the pickling bath 40 is not separated by a separate reference numeral, it may be composed of a plurality of unit pickling tanks, and in the pickling bath, the surface of the hot-rolled steel sheet passing through it using a high temperature strong acid such as hydrochloric acid or sulfuric acid is mainly used. The scale was chemically removed.

In this case, reference numeral 10 in FIG. 1 denotes a payoff reel, 20 denotes a welding machine, and 60 denotes a tension reel, and the water washing tank 50 is not specifically illustrated, but may be divided into a brush and a rinse cleaning step.

However, the existing descaling method based on pickling as shown in FIG. 1 increases the length of equipment according to the use of a plurality of pickling tanks and washing tanks, inhibits the working environment due to generation of acid vapors, causes environmental hazards due to waste acid treatment, and There have been various problems such as an increase in auxiliary facilities due to recovery and acid resistance facilities, a difference in scale removal capability according to steel grades, and a poor quality of the steel sheet stayed in the acid solution tank and the water washing tank when the line is stopped.

In addition, although schematically illustrated in FIG. 1, in the case of the existing pickling equipment, the length of the equipment of the pickling tank 40 and the washing tank 50 reaches approximately 100 M, and thus, the hot rolling of the pickling tank and the washing tank when the line stops. The steel sheet had poor surface quality due to excessive acid treatment. In addition, the installation space was considerable.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 2002-275666 or 2002-371314, etc., in order to replace the descaling of pickling, a shot ball, grit, or the like of metal is used. There is also a method of removing the scale of the steel plate surface by colliding with the steel plate surface.

However, such a physical removal method is also mostly parallel with the pickling process as a pretreatment step of the pickling process for improving the pickling efficiency, and is particularly difficult to apply to a hard pickling steel grade such as a grain-oriented electrical steel sheet.

In addition, there is known a method for removing scale through injection of high pressure water as in Japanese Patent Laid-Open No. 2004-074178, and a method for spraying ice particles as in US Pat. No. 6,328,631. The descaling performance was insufficient or difficult to use.

In addition, related facilities or processing methods for continuously linking physical scale removal with a rolling process or a plating process have been proposed in Japanese Patent Laid-Open No. 2003-064461 or US Pat. No. 6,088,895.

For example, Japanese Unexamined Patent Publication No. 2003-064461 suggests a tension leveler or a short blasting method as an auxiliary means for pickling, and in the case of US Patent No. 6,088,895, the surface roughness is 0.3 μm or less. Stainless steel cold rolled steel for adjustment is the object. However, in the case of the actual stainless steel sheet, it is difficult to effectively perform descaling effectively only by the method proposed in the US patent.

For example, the surface layer scale of the steel sheet promotes crack expansion in the scale breaker, removes the scale in the blasting step of the slurry (polishing slurry), and then passes through the skin pass mill and the polishing brush step to remove the scale, as well as the surface roughness. No technique has been proposed that implements control of.

The present invention has been proposed in order to solve the above-mentioned conventional problems, and an object thereof is to effectively remove the scales of steel sheets, especially hot rolled steel sheets, for example, non-oriented electrical steel sheets, by braking, slurry blasting, etc. The removed steel sheet is passed through the skin pass mill and the polishing brush means to realize the surface roughness management of the steel sheet, thereby providing an apparatus and method for surface treatment of a hot rolled steel sheet which is ultimately environmentally friendly and improves the surface quality of the steel sheet. Is in.

As a technical aspect for achieving the above object, the present invention, a scale breaker provided on the transfer path of the steel sheet;

A slurry spray unit provided to remove the scale on the downstream side of the scale breaker;

A skin pass mill provided downstream of the slurry spray unit; And

Polishing brush means provided downstream of the skin pass mill;

It provides a surface treatment apparatus of a steel sheet configured to include.

Preferably, it further comprises a brush means provided between the slurry injection unit and the skin pass mill.

More preferably, the polishing brush means comprises a plurality of polishing brush rolls.

More preferably, the slurry injection unit, the housing disposed in the chamber corresponding to the traveling path of the steel sheet; and the high pressure water injection means provided in the housing; and the abrasive provided in the housing to one side of the high pressure water injection means Input means; And slurry spraying means provided to spray the polishing slurry mixed with the high pressure water and the abrasive on the lower portion of the housing to the steel sheet.

More preferably, the high pressure water injection means, the high pressure water supply port is assembled to the upper portion of the device housing is supplied with high pressure water; And a high pressure water nozzle assembled to the high pressure water supply port and provided to spray the high pressure water in the housing.

In this case, the abrasive input means, including the abrasive input pipe connected to the housing, the abrasive is configured to be sucked into the housing by the negative pressure formed by the high-pressure water injection in the housing.

Preferably, the slurry injection means, the injection hole is assembled to the lower portion of the housing; and the injection portion, the depression formed by mixing the high pressure water and the abrasive to discharge; And a slurry injection hole provided in the slit structure through the injection hole from the depression.

More preferably, the mixing means further includes a mixing means provided to induce mixing of the high-pressure water injected into the housing and the introduced abrasive, wherein the abrasive has a specific gravity higher than that of metal, silicon oxide, silicon carbide, aluminum oxide, glass, and the like. It is formed of one of ceramics.

In addition, as another technical aspect, the present invention provides a scale for controlling roughness while passing the steel sheet through a scale breaker to promote cracking of the scale on the surface of the steel sheet, and spraying a slurry mixed with water and abrasive to remove the scale on the steel sheet surface. Removing step; And

A surface roughness control step of controlling the surface roughness by passing the descaled steel sheet through a skin pass mill and an abrasive brush roll;

It provides a surface treatment method of a steel sheet configured to include.

Preferably, the surface treatment apparatus of the said steel plate is used.

In addition, the solution of the said subject does not enumerate all the features of this invention. Various features of the present invention and its advantages and effects will be understood in more detail with reference to the following specific embodiments.

According to the present invention, it is possible to physically and effectively remove the scale of a steel sheet, in particular, a hot rolled hot rolled steel sheet, such as a non-oriented electrical steel sheet, by braking, slurry blasting, etc. By passing through the brush, the surface roughness of the steel sheet is precisely managed and the quality thereof is ultimately eco-friendly and provides the effect of improving the surface quality of the steel sheet.

Therefore, the present invention can omit or drastically reduce acid vapor generation, acid recovery and waste acid treatment processes generated in the existing pickling process, and according to the shortening of the equipment length, reduction of manufacturing cost, and processing of demand It provides various effects such as surface roughness adjustment and surface quality improvement.

1 is a schematic diagram showing a descaling process of a steel sheet through conventional pickling.
Figure 2 is an overall configuration diagram showing a surface treatment apparatus of the steel sheet through the scale and roughness management according to the present invention
3 and 4 is a block diagram and an exploded view showing a slurry spray unit of the present invention device
5 is a schematic diagram showing a state of recycling the slurry slurry of the present invention slurry injection unit

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

First, in FIG. 2, the whole structure of the surface treatment apparatus 1 of the steel plate which concerns on this invention is shown.

That is, as shown in FIG. 2, the surface treatment apparatus 100 of the steel plate of this invention is basically the scale breaker 300 provided on the conveyance path | route of a steel plate, and is demonstrated in detail in FIGS. The slurry spray unit 400 provided to remove the scale on the downstream side of the scale breaker 300, the skin pass mill 700 provided on the downstream side of the slurry spray unit, and the polishing provided on the downstream side of the skin pass mill. Including the brush means 800 may be provided as an example of the configuration.

Of course, as shown in FIG. 2, the steel sheet is basically released from the pay-off reel 110, and the line and trailing steel sheets 102 are welded by the welder 200, and finally, the steel sheet 102 is surface-treated by passing through the constituent means. ) Is wound on the tension reel 120.

More preferably, in the case of the device of the present invention, as shown in Figure 2, the brush means for removing the residual slurry between the slurry spray unit 400 and the skin pass mill 700, that is, brush roll is More is provided.

At this time, as shown in Figure 2, in the apparatus of the present invention, the brush roll 600 and the polishing brush means 800, that is, the polishing brush roll is a brush roll 602 and the polishing brush roll 802 through which the steel sheet passes These may include chambers 610 and 810 arranged above and below the steel sheet in a suitable pattern.

However, in the following description of the present embodiment, the brush means 600 and the polishing brush means 800 are weakly described as the brush roll 600 and the polishing brush roll 800, respectively.

Therefore, in the case of the surface treatment apparatus 100 of the steel sheet of the present invention shown in Figure 2, the scale of the non-oriented electrical steel sheet that requires more control (control) of surface roughness than hot rolled hot rolled steel sheet, for example, oriented electrical steel sheet It removes continuously and controls the surface roughness so that the surface quality may be optimal. As an example, the welder 200 and the scale breaker 300 are sequentially arranged between the pay-off reel 110 and the tension reel 120. ), Slurry spraying unit 400, brush roll 600, skin pass mill 700 and the polishing brush roll 800 is arranged to pass through the steel sheet, thereby effectively scaling the surface of the steel sheet without using an existing acid solution To make it removable.

In particular, the removal of the residual scale or slurry after the descaling is carried out through the brush roll 600, the steel sheet impact of the slurry containing the abrasive for such descaling, and the steel sheet having a rough surface after brushing is primarily The surface roughness is controlled using the skin pass mill, and finally, the polishing brush roll 800 is used to improve the surface quality of the steel sheet.

That is, the surface treatment apparatus 1 and the method of the steel sheet of the present invention shown in Figure 2, the hot-rolled steel sheet, in particular, the non-oriented electrical steel sheet of 3.5% or less of Si in the scale breaker 300 to bend under constant tension This causes the surface layer portion scale layer of the steel sheet to crack or promote cracking, and then the surface of the non-oriented electrical steel sheet having a scale layer containing a slurry ('S' in FIGS. 3 and 5) containing an abrasive having a predetermined particle diameter. Remove the scale by spraying at high pressure and high speed evenly in the width direction.

Next, in the case of the present invention, the slurry sprayed on the steel sheet for descaling is removed using the brush roll 600.

Then, in order to adjust the rough surface of the steel sheet subjected to the descaling step, that is, to control the surface roughness, the surface roughness of the steel sheet surface is controlled by first passing through the skin pass mill 700 having the rolling roll 702. The fine surface roughness of the surface of the steel sheet is continuously adjusted using the polishing brush roll 800 in succession.

That is, when the surface treatment step of the steel sheet according to the present invention is summarized, as shown in Figure 2, the steel sheet is passed through the scale breaker to promote cracking of the scale on the surface of the steel sheet, by spraying a slurry mixed with water and abrasives Descaling step to control the roughness while removing the scale of the steel sheet surface. The surface roughness control step of controlling the surface roughness by passing the descaled steel sheet through the skin pass mill and the polishing brush roll.

Of course, both the scale removal step and the surface roughness control step as described above may be to use the surface treatment apparatus 100 of the steel sheet according to the present invention shown in Figs.

In the case of the present invention as described above, although the descaling efficiency and surface roughness are improved than using a pickling bath, the length of the entire apparatus 100 (equipment) is 1/2 to 2/3 of the total length of the existing apparatus. This is due to the use of slurry spraying (blasting) and surface management in the first and second stages without the use of acid solutions.

On the other hand, as described above, in the case of a steel sheet, for example, non-oriented electrical steel sheet 102, a plurality of cracks are generated in the scale layer formed on the surface of the steel sheet while passing through the scale breaker 300.

Therefore, in the case of the scale breaker 300, the greater the elongation rate and the amount of bending work, the greater the amount of cracks generated, and thus, the scale layer on which the cracks are induced is slurry sprayed by the steel sheet described in detail with reference to FIGS. When passing through the unit 400, it is easily removed.

On the other hand, the scale breaker 300 in the present invention device 100 of Figure 2, although not shown separately in the drawing by a separate reference numeral, a tension bridle roll (tension bridle roll) that can give tension and elongation It consists of an anti-camber roll, a leveler roll, a bending roll, and the like, and the anti-camber roll and the leveler roll straighten the shape of the steel sheet.

At this time, the elongation and bending amount of the scale breaker 300 in the present invention device is preferably controlled to 1.0 ~ 4% and 30 ~ 70mm, respectively.

In addition, the slurry spraying speed and the spraying amount in the slurry (i.e., polishing slurry in which water and abrasive are mixed) for removing the scale in which the crack is formed in the scale breaker step, which will be described in detail below, are 70 to 70, respectively. It is preferable to adjust the range of 90 m / sec, and 1000 ~ 1400 kg / min, through which the surface roughness of the steel sheet in the descaling step is preferably in the range of 4 ~ 7㎛.

Next, as shown in FIG. 2, the steel sheet from which the residual slurry ('S' in FIGS. 3 and 5) and the scale (SC in FIG. 3) are removed from the brush roll 600 through the slurry spraying step is a skin pass mill 700 sequentially arranged. ), And the surface roughness of the steel sheet is adjusted to the range of 2.0 to 4.0 µm in the range of 5% or less of the rolling reduction, and finally, using a polishing brush roll 800 having a roughness of # 100 to # 240, The final surface roughness of the surface is controlled to be in the range of 0.5 to 1.5 µm.

That is, in the case of the apparatus of the present invention, since the steel sheet passes through the skin pad mill 700 and the polishing brush roll 800 for controlling the surface roughness of the steel sheet again, the steel sheet passes through the slurry spraying step. Since the surface roughness does not have to be operated so that the final 0.5 ~ 1.5㎛ range, it is possible to reduce the slurry injection pressure or the injection amount, which is as shown in Figure 7, broken abrasive abrasive sprayed on the steel sheet (Figs. The amount of C) can also be reduced, and the load on the plant, ie, to increase the pressure or flow, can be reduced.

Accordingly, in the case of the surface treatment apparatus 100 of the steel sheet of the present invention, the surface roughness according to slurry injection for scale removal as well as scale removal is controlled in the next step, so that the steel sheet having an optimum surface roughness, in particular, It is to enable the production of non-oriented electrical steel sheet.

Next, FIGS. 2 to 5 show in detail the slurry spray unit 400 for finally removing the scale on the surface of the steel sheet in the surface treatment apparatus 100 of the steel sheet of the present invention.

That is, as shown in Figure 2, the slurry spray unit 400 of the present invention, a plurality of chambers 402 through which the steel sheet passes therein may be provided in a suitable arrangement on the upper, lower side of the steel sheet.

Of course, the unit slurry injection unit 400 is a high pressure injection of water in the housing 410 through the abrasive supply line (L2) and high pressure water supply line (L1), the abrasive (C) to form a negative pressure space Slurry (S) mixed with high-pressure water (water) and abrasive (C) having a bead (grain) structure of a predetermined particle size through the injection hole of the housing through the injection port of the housing as shown in FIG. The high pressure and high speed are sprayed on the surface of the steel sheet 102, so that the abrasive can effectively remove the scale layer, and in particular, the roughness management of the surface of the steel sheet.

Therefore, the slurry injection unit 400 of the surface treatment apparatus of the steel sheet of the present invention will be described in detail based on the following FIGS. 3 to 5.

Basically, the slurry injection unit 400 of the present invention, as shown in Figures 3 and 4, the housing 410 is disposed corresponding to the traveling path of the steel sheet inside the chamber 402 of the box-shape described above And, the high pressure water injection means 430 provided in the housing, the abrasive input means 450 provided in the housing to one side of the high pressure water injection means, and a polishing slurry in which the high pressure water and the abrasive is mixed in the lower portion of the housing ( S) may be configured to include a slurry spraying means 470 provided to spray the steel sheet.

Therefore, when the abrasive C and the high pressure water, that is, the high pressure water W are inclined to the upper side and one side of the housing, the negative pressure space T is formed in the space inside the housing according to the high pressure water injection. The abrasive supply to the negative pressure space is smoothly performed without any external power application, so that the mixing of water and abrasive in the mixing zone (MT) is very dense, resulting in a very uniform distribution of water and abrasive. (S) is evenly sprayed on the surface of the steel sheet 102 through the injection means 470, which is to increase the scalability.

The slurry spray unit 400 of the present invention does not need the existing pickling tank (40 in FIG. 1), which simplifies the size of the equipment, and enables sufficient removal of the scale even when the steel sheet 102 is advanced at high speed. And average surface roughness Ra of the steel plate after descaling are managed uniformly to 1-1.5 micrometers.

Therefore, the surface treatment apparatus 1 of the steel sheet of the present invention not only secures the scale removal efficiency but also makes the surface roughness of the steel sheet after the scale removal appropriate, so that the processing characteristics, cold rolling, plating, etc. required by the demand for the steel sheet are required. It is possible to cope with various conditions of the surface roughness required in the subsequent process of.

On the other hand, such a slurry, that is, the abrasive included in the polishing slurry (S) to remove the scale layer by collision (C in Figs. 3, 5) is preferably provided as an abrasive having a specific gravity smaller than the metal, for example For example, it may be provided as silicon oxide, silicon carbide, aluminum oxide, glass, ceramic, or the like. Preferably, glass or ceramic beads having a uniform particle size are used.

The glass or ceramic beads of such an abrasive preferably have a particle diameter of about 10 to 400 m. For example, when the diameter of the abrasive is 10 μm or less, it is so fine that the effect of removing the scale layer on the surface of the steel sheet is insignificant. On the contrary, when the particle size of the abrasive is 400 μm or more, the scale removal efficiency is increased and the roughness deviation of the surface of the steel sheet is increased. Generated and undesirable.

On the other hand, it is preferable that the high-pressure water injection pressure injected from the inside of the housing 410 is also adjusted uniformly. Assuming that the glass beads having a particle diameter of 10 to 400 μm as described above, the high-pressure water injection pressure is 100 to 500 The range of bars is adequate. For example, when the pressure of the high-pressure water W is 100 bar or less, the slurry spraying pressure is small and the scale removal efficiency is insufficient. On the contrary, when the pressure of the high pressure water W is 500 bar or more, the steel plate impact pressure of the abrasive is high, and the surface roughness Ra of the surface of the steel sheet varies. Will be generated.

At this time, as described above, it is preferable to adjust the slurry injection speed and the injection amount in the range of 70 ~ 90 m / sec and 1000 ~ 1400 kg / min, respectively, wherein the surface roughness of the steel sheet is adjusted to 4 ~ 7㎛ range It is.

That is, outside the range of the slurry spraying speed and the spraying amount, the steel sheet surface collision force of the abrasive is small or excessively high, and the steel sheet, in particular, non-oriented through the next skin pass mill 700 and the polishing brush roll 800 It may be difficult to control the surface roughness of the electrical steel sheet in the range of 0.5 ~ 1.5㎛.

On the other hand, as shown in Figure 3 and 4, the housing 410 of the slurry spray unit 400 of the present invention, the high-pressure water injection means 430, abrasive injection means 450 and slurry injection means 470 Each of the first to third housings 412, 414, 416, which are associated or assembled, wherein the second housing is formed to be inclined, and the first and third housings are provided in a straight line as a whole.

And, as shown in Figure 3, the nozzle 434 of the high-pressure water injection means 430 is positioned at the point where the horizontal line CT2 meets the center vertical line CT1 of the second housing 414 to which the abrasive supply means 450 is connected. It is advantageous to ingress through the suction of abrasive.

That is, if the high-pressure water jet nozzle is too down or above, it may interfere with the inflow of the abrasive into the negative pressure space (T) or may cause a problem that the negative pressure space is too wide.

3 and 4, the high pressure water injection means 430 of the slurry injection unit 400 of the present invention is assembled to the first housing 412 side of the device housing 410, the high pressure water The high pressure water supply port 432 to which the supply pipe 436 is connected, and the high pressure water assembled at the lower end of the high pressure water supply port 432 to spray the inside of the housing to form negative pressure and increase water and abrasive mixing characteristics. Injection nozzle 434.

Therefore, in the case of the slurry injection unit 400 of the present invention, it is not limited to supplying the high pressure water to the interior of the housing 410, but adopting a double injection method of injecting the high pressure water from the interior of the housing 410. Therefore, the high pressure water injection pressure facilitates suction injection of the abrasive into the housing without external pressurization, and the high pressure water spray facilitates mixing of the abrasive, ie, glass beads or ceramic beads and water (high pressure water) (W). .

At this time, the high pressure water supply port 432 may be assembled to the housing and the high pressure water injection port 436 by passing through the lock cap 411 of the upper part of the device housing.

Meanwhile, in FIG. 3, reference numeral 'T' denotes a negative pressure space as a space directly under which high pressure water is injected, and reference numeral 'MT' denotes a mixing space in which the high pressure water W and the abrasive C are mixed.

Next, as shown in Figures 3 and 4, the abrasive input means 450 of the present invention, the abrasive input pipe 452 connected to the second housing 414 integrally formed to be inclined on one side of the housing 410. The abrasive C is thus smoothly sucked into the housing by the negative pressure formed by the injection of high pressure water inside the housing.

Next, as shown in FIGS. 3 and 4, the slurry spraying means 470 of the present invention is assembled inside the third housing 416 opened to the lower portion of the housing 410, and the set bolt 482 is disposed. Slurry injection hole 472, which is a cylindrical body fixed through, a concave depression 474 for additionally mixing high pressure water and abrasive material in the injection hole to discharge in a uniform distribution, and a slit structure through the injection hole from the depression It includes a slurry injection hole 476 provided to.

Accordingly, the slurry S in which the high pressure water and the abrasive are mixed in the mixing space MT is collected at the depression 474 concave toward the center of the injection hole 472 and is moved to the outside through the slurry injection hole 476 of the slit structure. It is injected at high pressure and high speed, and the slurry injected by the injection hole of the slit is sprayed while spreading with a length.

At this time, as shown in Figure 4, it is preferable to form a cutout 478 of a predetermined angle (Θ) on both sides of the lower portion of the injection hole 476 of the slit structure, such a cutout 478 is injected The slurry (slurry stream) S spreads more widely, making it possible to remove the scale of the steel sheet (SC in FIG. 3) more smoothly and in a larger area.

Actually, as shown in Figure 2, the slurry injection unit 400 of the present invention is arranged in a plurality of steel sheet width and length direction of the unit housings, the sprayed slurry is sprayed to overlap a portion.

At this time, the angle of the incision is preferably about 15 to 30 °, excessively narrow or wide angle causes a problem of less effect of the incision or slurry is dispersed. 3 and 4, reference numeral 480 is a fixing ring.

Next, in FIG. 3 and FIG. 4, a mixing means 490 may be installed to further induce mixing of the high pressure water injected into the housing and the introduced abrasive. For example, the mixing means 490 may be provided as a structure for densely connecting the cross bars to the circular frame, as shown in FIG. 4, and preferably, the two mixing means 490 are alternately provided with cross bars. will be.

Therefore, as shown in FIG. 3, the slurry S passing through the mixing space MT is further mixed with water and abrasive while passing through the mixing means 490 that is a lattice frame, which is abrasive in the slurry S sprayed onto the steel sheet. As a result, as shown in FIG. 3, when the slurry S (stream) is sprayed onto the steel sheet and collided with it, the abrasive has an even distribution and collides evenly with the surface of the steel sheet, which makes the roughness of the steel sheet uniform. will be.

Next, in FIG. 5, the slurry S used in the slurry spray unit 400 of the present invention described above, in particular, the reuse of the abrasive and the treatment of the scale SC peeled off the steel sheet and the broken abrasive (glass beads) It is shown.

That is, as shown in Figures 2 and 5, the high pressure water supply pipe 436 and the abrasive input pipe 452 of the slurry injection unit 400 arranged in the chamber 402, respectively, and the high pressure water supply line (L1) and The abrasive feed line L2 is connected.

At this time, as shown in Figure 5, the lower side of the chamber 402 is provided with a collecting hopper 510 for collecting the water and the abrasive and the peeled scale of the sprayed slurry, the collection hopper is a pump (PP) and the valve (V) The collected scale SC and the used abrasive C are introduced into the separation tank 516 linked to the cyclone 512 and linked to the lower portion of the cyclone 512.

Through the screen (unsigned) in the separation tank, the water is collected in the water reservoir 438 below, the water reservoir 438 is connected to the high-pressure water supply means 430 through the line (L1), abrasive (C ) Is supplied to the abrasive supply hopper 456 connected to the input pipe 452 of the abrasive input means 450 and the supply line (L2), the transfer equipment 454 for supplying a new abrasive is disposed on the upper side of the supply hopper At the bottom of the hopper, a screw feeder 458 for quantitative dispensing of the abrasive is operated.

On the other hand, in the separation tank 516, suspended scales and broken abrasives, etc. are introduced into the processing tank 514 through the overflow, where the abrasives such as scales and broken glass beads are separated from the magnet separator 518 and separated from the abrasives. It is scaled.

Thus, as shown in Figure 5, the slurry spray unit 400 of the present invention, through the associated abrasive and water and scale reprocessing and supply circulation facilities, to enable the treatment of the scale and damaged abrasive or recycling of the abrasive. .

At this time, although not shown with a separate sign in Figure 5, the recycled abrasive collected in the separation tank may be supplied to the abrasive supply hopper 456 in a dried state through a dryer (dashed line).

On the other hand, when the embodiment through the surface treatment apparatus 100 of the steel sheet of the present invention described so far as an example.

(Example 1)

The non-oriented electrical steel sheet (thickness 2.3 mm x width 1200 mm) containing 3.0 to 3.3% of Si, 0.3 to 0.5% of Mn, and 0.2 to 0.6% of Al was subjected to the following line speed of 50mpm using the apparatus of FIG. As a result of continuous sheet-flowing under the processing conditions as shown in the table, the residual scale was similar to the conventional pickling treatment, and the residual scale was less than 0.3%, and the average surface roughness of 0.3 to 1.2 µm level (0.9 to 1.3 µm for the pickling steel sheet) was obtained. The glossiness of the surface was also excellent.

division Treatment condition Scale breaker Elongation 1.2%, bending amount 50mm Slurry blasting Abrasive (glass bead, 100㎛), slurry spraying pressure 600Bar, slurry spraying angle 15 ° Slurry spraying unit and steel plate 300mm Skin pass mill Average roughness of the roll was 1.2 μm, rolling reduction 3.0% Abrasive brush 4 pairs of brush rolls (2 pairs of front rolls: # 120, 2 pairs of rear rolls: # 180), roll rpm 1000 rpm

(Example 2)

A non-oriented electrical steel sheet (thickness 2.3 mm x width 1200 mm) containing Si 2.0 to 2.9%, Mn 0.3 to 0.5%, and Al 0.2 to 0.6%, using the present invention of FIG. As a result of continuous sheet-flowing under the same conditions, compared with the conventional pickling treatment, the residual scale obtained a similar level of less than 0.2%, the average surface roughness of the steel sheet 0.3 ~ 1.0 ㎛ level (0.9 ~ 1.3 ㎛ for pickling steel sheet) The surface glossiness was also excellent.

division Treatment condition Scale breaker Elongation 1.2%, bending amount 50mm Slurry blasting Abrasive (glass beads, 100㎛), slurry spraying pressure 500Bar, slurry spraying angle 15 ° gap between slurry spraying unit and steel plate 300mm Skin pass mill Average roughness of the roll was 1.2 μm, rolling reduction 2.0% Abrasive brush 4 pairs of brush rolls (2 pairs of front rolls: # 120, 2 pairs of rear rolls: # 180), roll rpm 1000 rpm

(Example 3)

A non-oriented electrical steel sheet (thickness 2.3 mm x width 1200 mm) containing Si 1.0 to 1.9%, Mn 0.3 to 0.5%, and Al 0.2 to 0.6% was used at the speed of 50mpm using the apparatus of FIG. As a result of continuous sheet-flowing under the same conditions, the residual scale had a similar level of less than 0.15%, and an average surface roughness of 0.3 to 0.8 µm (0.9 to 1.3 µm for pickling steel). The surface glossiness was also excellent.

division Treatment condition Scale breaker Elongation 1.2%, bending amount 50mm Slurry blasting Abrasive (glass bead, 100㎛), slurry spraying pressure 400Bar, slurry spraying angle 15 ° gap between slurry spraying unit and steel plate 300mm Skin pass mill Average roughness of the roll is 1.2 μm, rolling reduction 1.0% Abrasive brush 4 pairs of brush rolls (2 pairs of front rolls: # 120, 2 pairs of rear rolls: # 180), roll rpm 1000 rpm

100 .... surface treatment unit of steel plate 300 .... scale breaker
400 .. slurry injection unit 410 .... housing
430 .... High pressure water injection means 450 .... Abrasive injection means
470 .... slurry injection means 490 .... mixing means
C ... abrasives (glass beads) S .... slurries (water + abrasives)
PP ... pump V ... valve

Claims (10)

A scale breaker 300 provided on a conveying path of the steel sheet;
A slurry spray unit 400 provided to remove the scale on the downstream side of the scale breaker 300;
A skin pass mill 700 provided downstream of the slurry spray unit; And
Polishing brush means 800 provided downstream of the skin pass mill;
Surface treatment apparatus of the steel plate comprising a. The method of claim 1,
Brush means 600 provided between the slurry injection unit and the skin pass mill;
Surface treatment apparatus of the steel sheet further comprising. The method of claim 1,
And the polishing brush means (800) comprises a plurality of polishing brush rolls (802). The method of claim 1,
The slurry injection unit 400, the housing 410 is disposed in the chamber 402 corresponding to the traveling path of the steel sheet;
High pressure water injection means (430) provided in the housing;
An abrasive input means 450 provided in one side of the high pressure water injection means; And
Slurry spraying means (470) provided to spray the slurry mixed with the high pressure water and the abrasive on the lower portion of the housing on a steel sheet;
Surface treatment apparatus of the steel plate comprising a. 5. The method of claim 4,
The high pressure water injection means 430, the high pressure water supply port 432 is assembled to the upper portion of the device housing is supplied with high pressure water; And
A high pressure water nozzle 434 assembled to the high pressure water supply port 432 so as to spray high pressure water in the housing;
Surface treatment apparatus for a steel sheet comprising a. 5. The method of claim 4,
The abrasive injection means 450, including the abrasive injection pipe 452 connected to the housing 410, the abrasive (C) is configured to be sucked into the housing by the negative pressure formed by the injection of high pressure water in the housing Surface treatment apparatus of the steel plate characterized by the above-mentioned. 5. The method of claim 4,
The slurry injection means 470, the injection hole 472 is assembled to the lower portion of the housing;
A depression 474 formed at the injection hole so that the high pressure water and the abrasive are mixed and discharged; And
A slurry injection hole 476 provided in a slit structure through the injection hole from the depression portion;
Surface treatment apparatus for a steel sheet comprising a. 5. The method of claim 4,
And mixing means 490 provided to induce mixing of the high-pressure water injected into the housing and the introduced abrasive.
The abrasive has a specific gravity greater than that of metal, the surface treatment apparatus of a steel sheet, characterized in that formed of one of silicon oxide, silicon carbide, aluminum oxide, glass and ceramic. A scale removing step of passing the steel sheet through a scale breaker to promote cracking of the scale on the surface of the steel sheet, and spraying a slurry mixed with water and abrasive to at least remove the scale of the steel sheet surface; And
A surface roughness control step of controlling the surface roughness by passing the descaled steel sheet through a skin pass mill and an abrasive brush roll;
Surface treatment method of the steel sheet comprising a. 10. The method of claim 9,
The surface treatment apparatus of the steel plate is used, The surface treatment apparatus (100) of any one of Claims 1-8 is used.

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