KR100419624B1 - Apparatus and method for preventing the growth of oxide layers on coil - Google Patents

Abstract

The present invention relates to an oxide film growth suppression apparatus and method for suppressing the growth of an oxide film generated in a coil wound after hot rolling and stored in a coil yard.

The present invention provides an apparatus for suppressing the growth of an oxide film generated in a wound coil, comprising: a cover for covering at least both sides of the coil, and an oxide film growth suppression apparatus for a coil cooled in a state where the coil is coated; Provide a method.

According to the present invention, since the cover covering at least both sides of the coil is provided, both sides of the coil are cooled in a state of being disconnected from the outside air, and the ingress of the inside air is prevented, so that the growth of the oxide film at the particularly edge of the coil is prevented. It is possible to suppress the formation of a thick oxide film at the edge with respect to the widthwise center part. As a result, the coil is thinly uniform in the width direction of the oxide film as a whole, and the pickling treatment time for selecting and removing the oxide film is greatly reduced to improve the conveyance speed of the rolled material in the pickling treatment, thereby improving the overall production efficiency. It is possible to improve and to reduce the consumption cost of pickling used.

Description

Apparatus and method for inhibiting oxide film growth of coils {APPARATUS AND METHOD FOR PREVENTING THE GROWTH OF OXIDE LAYERS ON COIL}

The present invention relates to an oxide film growth suppression apparatus and method for suppressing the growth of an oxide film generated in a coil wound after hot rolling and stored in a coil yard.

In general, coils wound after hot rolling and carried in coil yards in the form of coils are stored in one or multiple stages on the loading stand in the longitudinal or transverse direction as shown in FIGS. 13A and 13B. It is cooled by ventilation or forced ventilation. The time required for cooling these coils varies depending on the summer season and winter season, but on average it takes about 110 hours in summer and 80 hours in winter.

At this time, since the coil is left in the atmosphere of oxidation at high temperature and cooled for a long time, an oxide film grows on the surface of the coil for a long time, and air (oxygen) invades between the edges of both sides of the coil from the edges of the coil to the coil width direction. As a result, the growth of the oxide film appears in a state where the thickness is greatly changed.

Fig. 14 shows the result of measuring the relationship between the growth thickness of the oxide film and the distance from the edge of the coil. In FIG. 14, the oxide film grows to about 8 μm in thickness during hot rolling, and then the oxide film grows to 18 μm when the wide gap is close to the edge part depending on the gap (GAP) of the steel sheet layer. The 50mm inner side grows up to 15 µm in the portion, the 300mm inner side grows up to 9 µm in the edge portion, and the central portion of the 470mm inner portion grows up to 8.5 µm in the edge portion and grows greatly differently in the coil width direction. That is, in the coil-shaped strip, the thickness of the oxide film at the center is about 8.5 占 퐉, whereas the edge portion is 18 占 퐉, and the oxide film is formed more than twice as thick.

As described above, the coil stored in the coil yard is cooled and removed from the pickling line, and then sent to a plating line for each use to commercialize the coil. At this time, since the pickling line is operated at a speed capable of removing the maximum oxide film thickness of about 18 μm from the coil edge portion, the center portion of the steel plate width has a problem that excess acid wash occurs more than necessary and the processing speed is slowed, so that productivity is not improved. There is also a problem in that a large amount of pickling liquid is removed to remove the oxide film grown in the coil yard.

The present invention has been invented to solve the conventional problems as described above, by reducing the growth of about 18㎛ of the oxide film generated in the strip stored in the coil state to shorten the pickling time and to prevent the loss of iron to be oxidized and removed, and An object of the present invention is to provide an apparatus and method for inhibiting oxide film growth of an improved coil to prevent loss of pickling liquid.

1 is a front view of an oxide film growth suppression apparatus of a coil according to a first embodiment of the present invention;

2 is a side view of FIG. 1;

3 is an exploded perspective view of the oxide film growth suppression apparatus of the coil;

4 is a graph showing the thickness of the oxide film in the width direction of the coil in the first embodiment;

5 is a front view of an oxide film growth suppression apparatus of a coil in accordance with a second embodiment of the present invention;

6 is a side view of FIG. 5;

7 is a graph showing the thickness of the oxide film of the width direction of the coil in the second embodiment;

8 is a graph showing a temperature with respect to a coil cooling time;

9 is a front view of an oxide film growth suppression apparatus of a coil according to a third embodiment of the present invention;

10 is a side view of FIG. 9;

11 is a front view of an oxide film growth suppression apparatus of a coil according to a fourth embodiment of the present invention;

12 is a side view of FIG. 11;

13 a) and b) are schematic views showing a storage state of a general coil;

14 is a graph showing the thickness of the oxide film in the width direction of a coil in a conventional storage state.

Explanation of symbols on the main parts of the drawings

11,12 ..... COVER 13 ..... L type bolt

17 ..... Eyring 19,20 ..... Insulation

35,36 ..... 42 ..... gas supply line

43 ..... 51 gas exhaust furnace

52 ..... lid 63,64 .... insulation

C ...... coil

In order to achieve the above object, the present invention, in the apparatus for suppressing the growth of the oxide film generated in the wound coil, provided with a cover covering at least both sides of the coil, the cover is provided in the hollow portion of the coil By providing an oxide film growth suppression apparatus of the coil, characterized in that the supply passage and the discharge passage for providing an inert gas of the.

And this invention has the structure which provided the heat insulating material in the close_contact | adherence surface with a coil to the said cover | cover.

In addition, the cover is installed in a cooling water passage to further cool the cover.

The cover has a configuration in which an inert gas supply passage and a discharge passage into the hollow portion of the coil are provided.

In addition, the present invention, in order to achieve the above object, in the method of suppressing the growth of the oxide film generated in the coil wound, the cover of at least both sides of the coil by a cover, and inert in the hollow portion of the coil The present invention provides a method for inhibiting oxide film growth of a coil, wherein the coil is supplied and discharged, converted into a non-oxidizing atmosphere, and cooled.

In the above method, the present invention is to cool while insulating the close contact between the cover and the coil.

In addition, the cooling water flows through the cooling water passage provided in the cover to cool.

Then, the inert gas is supplied to and discharged from the hollow portion of the coil to cool.

Hereinafter, the configuration of the present invention in detail with reference to the accompanying drawings.

In FIG. 1, the oxide film growth suppression apparatus 10 according to the first embodiment of the present invention has a coil side cover 11 formed on both sides of the coil in the same or greater size than the side shape of the coil C. (12) And the coupling between the coil side cover 11 and the cover 12 by coupling the coil between the coil side cover 11 and the cover 12 is composed of.

The coil side covers 11 and 12 may have the same symmetrical structure as shown in FIG. 3, and are formed by adhering elastic heat-resistant materials 19 and 20 to one side thereof, and The sphere consists of an eyering (17) 18 provided at two inner portions of the side covers (11) and (12) of the coil, and an L bolt (13) and a nut (14) inserted into and passed through the eyerings (17) and (18). It is. These two couplers can be installed at any symmetrical position of the holes 15 and 16 of the coil side covers 11 and 12, and any suitable means other than bolts and nuts can be used.

Meanwhile, the present invention may have a second embodiment as shown in FIGS. 5 and 6. The coolable oxide film growth suppression apparatus 30 according to the second embodiment of the present invention includes a pair of cap-type covers 31 and 32 covering the entire side of the coil C, and the cover 33 Cooling pipe connection part is provided in the center of the (32), and the gas supply pipe (42) is connected to one side cover (31) by connecting the gas supply pipe (41) for cooling, and the gas discharge pipe (44) on the other cover (32). To connect the gas discharge passage 43.

In addition, each of the caps 31 and 32 is configured to have a cooling water channel 35 and 36 embedded therein, and the inlets 37 and 38 and the outlet 39 of the cooling water channel 35 and 36 ( 40) is connected to a water supply system and a drain system.

Here, the cooling gas flowing into the coil through the cooling gas supply pipe 41 of the one side cover 31 and discharged to the outside through the discharge path 43 of the other cover 32 scatters the oxidation atmosphere. In order to substitute the chemical atmosphere, an inert gas such as nitrogen gas or argon gas can be forcedly flowed by a pump at room temperature as necessary. In addition, the coolant flowing into the coolant flow channels 35 and 36 through the inlets 37 and 38 of the respective caps 31 and 32, and the coolant flowing out through the outlets 39 and 40 to the outside is pumped. It can be configured to. In addition, the cap-shaped cover (31, 32) covering both sides of the coil may be formed of a coolant distribution channel (35) (36) between them by a double plate of iron plate, it is configured to sandwich them on both sides of the coil respectively. If necessary, the outer side of each other may be pressed by a connecting bolt (not shown) or the like as necessary.

9 and 10 show an oxide film growth suppression apparatus 50 according to a third embodiment of the present invention. This oxide film growth suppression apparatus 50 is comprised in the container shape which can accommodate and take out high temperature coil C as it is. 9 and 10, the cylindrical oxide film growth suppression apparatus 50 with a lid is fitted to the cylindrical cup-shaped main body 51 slightly larger than the outer shape of the coil and the opening of the cylindrical cup-shaped main body 51. It is composed of a lid 52 of the cap.

The oxide film growth suppression apparatus 50 supports the coil 51 in a state in which the coil C is supported by an L-shaped fork of a forklift (not shown) when the coil C arrives at the coil yard at a high temperature. C), the main body 51 and the coil are placed on the mounting base 21, and then the L-shaped fork is removed, and the cap 52 is capped with the main body 51. The coil C is air-blocked by the entire body 51 and the lid 52 and naturally cooled together with the body 51 and the lid 52 of the oxide film growth suppression apparatus 50.

11 and 12 show an oxide film growth suppression apparatus 60 according to a fourth embodiment of the present invention. The oxide film growth suppression apparatus 60 is almost similar to that of the third embodiment. 11 and 12, the oxide film growth suppression apparatus 60 of the fourth embodiment is fitted with a cylindrical cup-shaped main body 61 slightly larger than the outer shape of the coil and an opening of the cylindrical cup-shaped main body 61. It consists of the cap 62 of the cap which can be. The heat insulating materials 63 and 64 are attached to the outer surfaces of the main body 61 and the lid 62, respectively.

The oxide film growth suppression apparatus 60 supports the main body 61 in a state in which the coil C is supported by an L-shaped fork of a forklift (not shown) when the coil C arrives at the coil yard at a high temperature. C), the main body 61 and the coil are placed on the mounting base 21, and then the L-shaped fork is removed and the cap 62 is capped on the main body 61. The coil C is naturally cooled in a state in which air is blocked by the entire main body 61 and the lid 62 and kept warm by the heat insulating materials 63 and 64.

Hereinafter, the operation and effects related to the first to fourth embodiments of the present invention will be described in detail.

(Example 1)

The oxide film growth suppression apparatus 10 of the first embodiment shown in FIGS. 1 to 3 covers both sides of the coil C wound in the winding machine of the hot rolling facility as covers 11 to cover the coil C. Mount it. The side cover 11 of the coil is a portion of the elastic heat-resistant material 19 is pressed on the edge surface of the coil (C) to block the gap between the plate edge of the coil edge and there is no air intrusion between the plate surface from the edge interval so that near the edge of the steel sheet It is possible to prevent the formation of a thick oxide film in the. The coil C is placed in the coil yard with this device mounted and allowed to cool naturally.

FIG. 4 is a diagram showing the result of measuring the relationship between the growth thickness of the oxide film and the distance from the coil edge of the coil in which the natural cooling is completed with the oxide film growth suppression apparatus 10 of the first embodiment mounted. . As shown in Fig. 4, the growth thickness of the oxide film in the edge portion in the coil yard is reduced to about 9 µm in total in addition to the growth amount during finishing rolling, so that the growth thickness of the entire oxide film in the coil C width direction is reduced. The effect of homogenizing was obtained.

(Example 2)

Meanwhile, in the oxide film suppressing apparatus 30 according to the second embodiment of the present invention shown in FIGS. 5 and 6, when the high temperature coil C is placed on the coil yard, the cover 31 is formed on the side of the coil C. 32) to be mounted on. Since the pair of cap-shaped covers 31 and 32 cover and seal the entire side surface of the coil C, the entire side surface except the outer circumferential surface of the coil C is in a state where air is blocked. In this state, an inert cooling gas flows into the hole of the coil C to form a non-oxidizing atmosphere, and the coil is cooled from the inside, and at the same time, coolant flows through the cap-shaped covers 31 and 32 to cool the coil from the edge. .

Fig. 7 shows the result of measuring the relationship between the growth thickness of the oxide film and the distance from the edge of the coil plate with respect to the coil having been cooled in the state where the oxide film suppressing device 30 of the second embodiment is mounted. As shown in Fig. 7, the growth thickness of the oxide film generated in the coil yard was reduced to about 9 µm in total in addition to the growth amount during finishing rolling in the entire coil width of the coil and was substantially constant throughout the width of the coil C. A uniform thickness effect can be obtained. As a result, when removing the oxide film from the pickling line in the coil C as in Example 1, there is no unnecessary removal of the portion other than the oxide film, that is, the base material, thereby reducing the pickling liquid and improving the productivity.

8 shows the measurement results of the cooling time between the case according to the second embodiment of the present invention and the case of normal natural air cooling. The cooling time was shortened by nearly 20% compared to natural air cooling, resulting in the effect of increasing the coil circulation efficiency in the coil yard.

(Example 3)

In the oxide film growth suppression apparatus 50 according to the third embodiment of the present invention, when the coil C arrives at the coil yard at a high temperature, the coil 51 is supported by the main body 51 while supporting the coil with an L-shaped fork. After placing on the mounting bracket 21 fitted in C), remove the L-shaped fork and cover the cap 52 on the cap. The coil C is air-blocked by the entire body and the lid 52 and is naturally cooled together with the body 51 and the lid 52 of the oxide film growth suppression apparatus 50. The entire thickness of the coil is cut off from the oxidation atmosphere, and the oxide film growth thickness at the end of cooling can be suppressed to a uniform value in the width direction of about 9 μm as in the case of Example 1 shown in FIG. In addition, since the high temperature coil C is gradually cooled for a long time, the effect of increasing the ductility of the coiled steel sheet can be obtained by the loosening effect.

(Example 4)

When the oxide film growth suppression apparatus 60 according to the fourth embodiment of the present invention is used, the cooling time is longer by the heat insulating materials 63 and 64 than in the third embodiment, so that the ductility of the coil steel sheet due to slow cooling is increased. Can be obtained. The other effect is the same as that of Example 3.

As described in detail in the various embodiments described above, according to the oxide film growth suppression apparatus of the coil of the present invention, first, since a cover covering at least both sides of the coil is provided, both sides of the coil are cooled in a state of being disconnected from the outside air. Intrusion of air inside is prevented, so that the growth of the oxide film at the edge of the coil is suppressed, and it is possible to prevent the formation of a thick oxide film at the edge with respect to the central portion in the width direction. As a result, the coil is thinly uniform in the width direction of the oxide film as a whole, and the pickling treatment time for selecting and removing the oxide film is greatly reduced to improve the conveyance speed of the rolled material in the pickling treatment, thereby improving the overall production efficiency. It is possible to improve and to reduce the consumption cost of pickling used.

Second, because the cover is installed in close contact with the coil in the cover, it prevents local rapid cooling of the coil and prevents the intrusion of air into the inside, thereby forming a thick oxide film at the edge of the widthwise center part. It is possible to prevent it, and it is possible to make an oxide film as a whole thin and to equalize in the width direction.

Third, since the cooling water passage is installed in the cover, the coil is forcedly cooled by the cooling water in a state where both sides are disconnected from the outside air, and the cooling time can be shortened to improve the circulation efficiency of the coil in the coil yard.

Fourth, since the inlet gas supply and discharge paths are installed in the hollow part of the coil in the cover, the coil is disconnected from the outside air at both sides, and the inert gas is supplied into the hollow part to prevent air from entering the inside. It is possible to reliably suppress the growth of the oxide film of the rolled material by replacing the oxidation atmosphere of the non-oxidation atmosphere.

Fifth, since at least both sides of the coil wound after rolling were cooled by the cover, the intrusion of air into the coil was prevented, and the growth of the thick oxide film at the edge of the coil was restrained, so that the center of the width direction was restrained. It is possible to prevent the formation of a thick oxide film at the edge. As a result, the overall thickness of the oxide film can be made uniform in the width direction of the coil.

Sixth, by cooling while insulating the close contact between the cover and the coil, local rapid cooling of the coil is prevented, and air intrusion is surely prevented to prevent the formation of a thick oxide film at the edge in the center of the width direction. It is possible to make the oxide film overall thin and uniform in the width direction.

Seventh, because the cooling water is distributed through the cooling water passage installed in the cover, the coil is forcedly cooled by the cooling water while both sides are disconnected from the outside air, and the cooling time is shortened to improve the circulation effect of the coil in the coil yard. It is possible to let.

Eighth, since inert gas is supplied to and discharged from the hollow part of the coil to cool the coil, both sides of the coil are disconnected from the outside air and inert gas is supplied to the hollow part, thereby preventing the intrusion of air into the interior. Is substituted with a non-oxidizing atmosphere, it is possible to reliably suppress the growth of the oxide film of the rolled material.

Claims (8)

In the apparatus for suppressing the growth of the oxide film generated in the wound coil, A cover for covering at least both sides of the coil is provided, and the cover is provided with an oxide film growth suppression device, characterized in that the supply passage and the exhaust passage for providing an inert gas into the hollow portion of the coil. The coil oxide film growth suppression apparatus according to claim 1, wherein the cover is provided with a heat insulating material in close contact with the coil. The coil oxide film growth suppression apparatus according to claim 1, wherein the cover is provided with a cooling water passage. delete In the method of suppressing the growth of the oxide film generated in the wound coil, At least both sides of the coil are covered with a cover, and an inert gas is supplied to and discharged into the hollow portion of the coil to convert to a non-oxidizing atmosphere to cool the oxide film. The method of inhibiting oxide film growth of a coil according to claim 5, wherein the coil is cooled while adiabaticly in contact with the cover between the coil and the coil. 6. The method of inhibiting oxide film growth of a coil according to claim 5, wherein the cooling water is circulated through the cooling water passage provided in the cover. delete