JP6350456B2 - Hot-rolled steel descaling method and descaling apparatus, hot-rolled steel material manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a descaling method and descaling apparatus for hot-rolled steel, and a hot-rolled steel manufacturing method and manufacturing apparatus.

  In a line for rolling hot-rolled steel, rolling is generally performed after removing a scale (oxide film) generated when the steel is heated. The primary scale generated in the heating furnace is thicker than the secondary scale generated outside the heating furnace after the removal of the primary scale, and if rolling is performed with the primary scale remaining, there is a problem that scale flaws are generated. .

  In addition, since the scale is generated not only on the upper and lower surfaces of the steel material, but also on the side surface, if the scale on the side surface of the steel material is not removed, for example, scale wrinkles may occur when rolling with a roll. In addition, even when rolling is not performed with a roll, when the scale is rolled with a horizontal roll, the scale generated on the side surface of the steel material peels around the rolling mill and adheres to, for example, the lower surface of the steel material during subsequent rolling. As a result, scale wrinkles may occur.

  Many methods for removing the scale on the steel surface have been proposed so far. For example, Patent Document 1 proposes a descaling method in which a descaling header is installed above and below the rolling line to remove the scale on the upper and lower surfaces of the steel. Has been. Moreover, in patent document 2, in order to remove the scale produced | generated on the steel material side surface, the descaling method which repeatedly injects high pressure water to a steel material side surface linearly is proposed.

  Patent Document 3 proposes a descaling method in which a scale is removed by pressing a brush roll against a steel material side surface. And in patent document 4, the descaling apparatus which removes the scale of a steel material side surface by inclining the several descaling nozzle of the width direction both ends among the descaling nozzles installed in the upper direction and the downward direction to the width direction inner side. Has been proposed.

JP 2002-102915 A Japanese Patent Laid-Open No. 10-137834 JP-A-8-197130 JP 2008-221328 A

  Here, since the descaling method proposed in Patent Document 1 descals only the upper and lower surfaces of the steel material, as described above, when the side surface of the steel material is rolled with a cocoon roll, a scale cocoon is generated, Even if it is not rolled, there was a problem that the scale peeled off from the side surface adhered to the lower surface of the steel material and scale flaws were generated.

  Moreover, since the descaling method proposed by patent document 2 injects linear high pressure water, the range which can be descaled per unit time is narrow, and the descaling speed is slow. Therefore, in order to remove all the scales on the side of the steel material, it is necessary to slow down the steel conveying speed in accordance with the descaling speed. However, there is a problem that the temperature control becomes difficult and material variations occur.

  Further, in the descaling method proposed in Patent Document 3, when the scale on the side surface of the steel material is removed by the brush roll, the brush roll is clogged by the scale or the brush is worn, so that the desired capability is obtained. There was a problem that could not be demonstrated.

  And, as shown in FIG. 4A, the descaling device 101 proposed in Patent Document 4 has a smaller amount of descaling water injected on the side surface of the steel material S1 than the upper surface or the lower surface of the steel material S1. When a scale equivalent to the upper surface or the lower surface is also generated on the side surface, there is a problem that the scale on the side surface remains and scale wrinkles occur.

  Further, as shown in FIG. 4A, the descaling apparatus 101 proposed in Patent Document 4 basically assumes that the scale of the narrow steel material S1 is removed. The plurality of attached descaling nozzles are divided into a descaling nozzle 132a for descaling the upper surface of the steel material S1 and a descaling nozzle 132b for descaling the side surface of the steel material S1.

  Therefore, in this descaling apparatus 101, when descaling a wide steel material S2 as shown in FIG. 4B, the amount of descaling water injected on the side surface of the steel material S2 is small, and the scale of the side surface of the steel material S2 is small. There was a problem that it remained more easily. Furthermore, when the descaling device 101 descals the wide steel material S2 as shown in the figure, the descaling water jetted from the descaling nozzle 132b is converted into descaling water jetted from the descaling nozzle 132a. When they are joined, there is a problem that temperature variation occurs in the width direction of the steel material S2 and the material varies.

  The present invention has been made in view of the above, and a descaling method and descaling of a hot rolled steel material that can reliably remove the scale on the side surface of the steel material and ensure a high-quality steel material with less scale defects. An object is to provide an apparatus, a method for manufacturing a hot rolled steel material, and a manufacturing apparatus.

  In order to solve the above-described problems and achieve the object, a hot-rolled steel material descaling method according to the present invention is a hot-rolled steel material descaling method that removes the scale generated during the heat treatment of the steel material before rolling. An upper descaling header for the upper surface and a descaling header for the lower surface are installed in the width direction of the steel material, and nozzles attached to the upper descaling header for the upper surface and the descaling header for the lower surface, respectively, Injecting descaling water on the lower surface, and a side descaling header is installed on either the upper surface descaling header or the lower surface descaling header, and from the nozzle attached to the side descaling header, The descaling water is sprayed on the side surface of the steel material, and the upper surface deske The descaling water is sprayed from the nozzles of the side descaling header so as not to overlap the spraying area of the descaling water sprayed from the nozzles of the ring header and the descaling header for the lower surface. To do.

  Further, in the above-described invention, the method for descaling hot-rolled steel according to the present invention is the method according to the present invention, in which the descaling water is injected from the nozzle of the descaling header for the side surface onto the side surface of the steel material and then rolled. The descaling water is jetted at a predetermined angle with respect to the upper surface of the steel material in a direction opposite to the conveying direction of the steel material.

  In order to solve the above-described problems and achieve the object, the hot-rolled steel descaling apparatus according to the present invention is a hot-rolled steel descaling apparatus that removes the scale generated during the heat treatment of the steel before rolling. An upper surface descaling header and a lower surface descaling header, which are installed in the width direction of the steel material, and nozzles for injecting descaling water onto the upper and lower surfaces of the steel material, respectively, and the upper surface descaling header Or a descaling header for a side surface installed on one of the descaling headers for the bottom surface, and a nozzle for injecting the descaling water on the side surface of the steel material, and the nozzle of the descaling header for the side surface , Nozzles of the descaling header for the upper surface and noses of the descaling header for the lower surface So as not to overlap with the injection region of the descaling water sprayed from, characterized in that injecting the descaling water.

  Further, in the above-described invention, the hot-rolled steel descaling apparatus according to the present invention includes a plurality of nozzles of the upper surface descaling header and a nozzle of the lower surface descaling header arranged in the width direction of the steel material, and Injecting the descaling water toward the upstream side in the conveyance direction of the steel material, and on the side surface of the upper surface descaling header or the side surface of the lower surface descaling header, the outermost nozzle in the upper surface descaling header or The side-side descaling header is provided with a header position adjusting means that is installed at a predetermined distance in the width direction of the steel material from the outermost nozzle in the bottom surface descaling header and protrudes in the length direction of the steel material. Is installed at the tip of the header position adjusting means, and the side decalin Nozzle headers, characterized by injecting the descaling water toward the upstream side or downstream side in the transport direction of the steel material.

  Further, in the above-described invention, the hot-rolled steel descaling apparatus according to the present invention includes a plurality of nozzles of the upper surface descaling header and a nozzle of the lower surface descaling header arranged in the width direction of the steel material, and The descaling water is sprayed toward the upstream side in the conveying direction of the steel material, and the descaling header for the side surface is disposed under the top surface descaling header or above the bottom surface descaling header. The outermost nozzle in the scaling header or the outermost nozzle in the lower-side descaling header is installed at a predetermined distance in the width direction of the steel material, and the nozzle of the side descaling header is in the conveying direction of the steel material The descaling water is jetted toward the downstream side of .

  In order to solve the above-described problems and achieve the object, a method for producing a hot-rolled steel according to the present invention is characterized in that descaling is performed using the descaling method described above.

  In order to solve the above-described problems and achieve the object, a hot-rolled steel manufacturing apparatus according to the present invention includes the aforementioned descaling apparatus.

  According to the present invention, the descaling water sprayed from the nozzles for the upper surface, the lower surface, and the side surface does not collide with each other on the path until the steel material collides, thereby reducing the descaling capability. Can be prevented. Therefore, it is possible to reliably remove the scale on the side surface of the steel material and secure a high-quality steel material with less scale wrinkles.

FIG. 1A is a plan view schematically showing a state in which descaling water ejected from the lower-side descaling nozzle collides with descaling water ejected from the side-side descaling nozzle in the descaling apparatus. is there. FIG. 1B schematically shows a state in which the descaling water ejected from the upper-side descaling nozzle and the lower-side descaling nozzle collides with the descaling water ejected from the side descaling nozzle in the descaling apparatus. FIG. FIG. 2 is a plan view schematically showing the configuration of the descaling apparatus according to the first embodiment of the present invention. FIG. 3 is a plan view schematically showing the configuration of the descaling apparatus according to the second embodiment of the present invention. FIG. 4A is a plan view schematically showing a state in which a narrow steel material is descaled by the descaling apparatus proposed in Patent Document 4. FIG. FIG. 4B is a plan view schematically showing a state in which a wide steel material is descaled by the descaling apparatus proposed in Patent Document 4.

  Hereinafter, embodiments of a descaling apparatus for hot rolled steel according to the present invention and a descaling method thereof will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[First Embodiment]
The descaling apparatus according to the present invention removes the scale generated during the heat treatment of steel before rolling. The descaling device is installed, for example, on the outlet side of the heating furnace, the inlet side and the outlet side of the roughing mill in a hot rolling line for manufacturing hot rolled steel materials (hot rolled steel strip, thick plate, strip steel, etc.). .

  Here, with respect to the upper and lower surfaces of the steel material after the heat treatment, descaling has been conventionally performed by injecting descaling water (high pressure water) (for example, Patent Document 1). When descaling the side surface, for example, a configuration shown in FIGS. 1A and 1B is assumed.

  As shown in FIGS. 1A and 1B, the descaling apparatus 101A includes a bottom descaling header 111A to which a plurality of bottom descaling nozzles 112A (hereinafter simply referred to as nozzles 112A) are attached, and a plurality of side surface descaling. A side scaling descaling header 121A to which a nozzle 122A (hereinafter simply referred to as nozzle 122A) is attached; a top scaling descaling header 131A to which a plurality of top scaling descaling nozzles 132A (hereinafter simply referred to as nozzle 132A) are attached; It has. Further, in the descaling apparatus 101A, a side descaling header 121A is installed on the bottom descaling header 111A.

  Here, in the descaling of the steel material S1, as shown in FIG. 1A, in order to avoid the improvement of the descaling capability and the removal of the removed scale on the upper surface of the steel material S1, the conveyance direction is increased. In general, descaling water is jetted toward the upstream side. Also, as shown in the figure, by installing the side descaling header 121A on the bottom descaling header 111A, it is possible to reduce the equipment cost compared to the case where the side descaling header 121A is separately installed. .

  However, when the steel material S1 having a small width is descaled by such a descaling apparatus 101A, as shown in FIG. 1B, a part of the nozzle 112A for the lower surface and a part of the nozzle 132A for the upper surface are made of the steel material S1. And the descaling water from the protruding nozzles 112A and 132A does not hit the steel material S1.

  Then, as shown in FIG. 1B, the descaling water jetted from the protruding nozzles 112A and 132A collides with the descaling water jetted from the side nozzle 122A, and the jet pressure of the nozzle 122A decreases. End up. Thereby, the descaling capability with respect to steel material side surface Sa falls, a scale remains, and a scale flaw may generate | occur | produce in a subsequent rolling process.

  Therefore, the descaling apparatus 1 according to the first embodiment of the present invention is configured as shown in FIG. 2 in order to solve such a problem. Hereinafter, the configuration of the descaling apparatus 1 will be described in detail. Note that the descaling header for the upper surface and the nozzle thereof in the descaling apparatus 1 are the same as those of the descaling apparatus 101A (see FIG. 1B), and are not shown in FIG.

  The descaling apparatus 1 includes an upper surface descaling header, an upper surface descaling nozzle (hereinafter simply referred to as a nozzle), a lower surface descaling header 11, and a lower surface descaling nozzle 12 (hereinafter simply referred to as nozzle 12). A side descaling header 21, a side descaling nozzle 22 (hereinafter simply referred to as a nozzle 22), and a header position adjusting means 23.

  The upper-side descaling header (not shown) is installed above the steel material S1 and is installed in the width direction of the steel material S1 in the same manner as the upper-surface descaling header 131A (see FIG. 1B). Moreover, a plurality of nozzles are attached to the descaling header for the upper surface in the downward direction, that is, toward the upper surface of the steel material S1, so that the descaling water can be sprayed onto the upper surface of the steel material S1.

  A plurality of nozzles (not shown) for the upper surface are arranged at a predetermined pitch in the width direction of the steel material S1 at the lower part of the descaling header for the upper surface, similarly to the nozzle 132A (see FIG. 1B). Further, the nozzle is installed at a predetermined angle of attack on the upstream side of the transport direction with respect to the upper surface of the steel material S1, and is inclined at a predetermined angle in the direction opposite to the transport direction of the steel material S1 so as to eject the descaling water. It is configured. Moreover, the injection area | region of the descaling water injected from this nozzle inclines with the predetermined | prescribed twist angle with respect to the conveyance direction of steel material S1. In the upper surface nozzle, the angle of attack indicates the angle of the nozzle with respect to the upper surface of the steel material S1, and the twist angle indicates the angle of the descaling water injection region with respect to the length direction of the steel material S1.

  As shown in FIG. 2, the lower-side descaling header 11 is installed below the steel material S <b> 1 and is installed in the width direction of the steel material S <b> 1. A plurality of nozzles 12 are attached to the lower surface descaling header 11 in the upward direction, that is, toward the lower surface of the steel material S1, so that descaling water can be sprayed onto the lower surface of the steel material S1 in a spray form. .

As shown in FIG. 2, a plurality of lower surface nozzles 12 are arranged at a predetermined pitch in the width direction of the steel material S <b> 1 at the upper portion of the lower surface descaling header 11. The nozzle 12 is installed at a predetermined angle of attack (not shown) on the upstream side of the transport direction with respect to the lower surface of the steel material S1, and is tilted by a predetermined angle in the direction opposite to the transport direction of the steel material S1. Inject. Further, as shown in FIG. 2, the spray area of the descaling water sprayed from the nozzle 12 is inclined with a predetermined twist angle θ _{1 with} respect to the conveying direction of the steel material S1. Note that in the nozzle 12 for the lower surface, the angle of attack and shows the angle of the nozzle 12 with respect to the lower surface of the steel material S1, the twisted angle theta ₁ shows the angle of the injection region of the descaling water to the length direction of the steel material S1 .

  The side descaling headers 21 are installed on both sides in the width direction of the steel material S1. In FIG. 2, only the side-side descaling header 21 installed on one side in the width direction of the steel material S1 is illustrated.

  The side descaling header 21 is installed in the thickness direction of the steel material S1 in the same manner as the side descaling header 121A (see FIG. 1B). Similarly to the nozzle 122A (see FIG. 1B), a plurality of nozzles 22 are attached to the side descaling header 21 in the lateral direction, that is, toward the steel material side surface Sa, and descaling water is supplied to the steel material side surface Sa. It is configured so that it can be sprayed.

A plurality of side surface nozzles 22 are arranged at a predetermined pitch in the thickness direction of the steel material S1 on the side surface of the side surface descaling header 21 in the same manner as the nozzle 122A (see FIG. 1B). In addition, as shown in FIG. 2, the nozzle 22 is installed at a predetermined angle of attack θ ₂ on the upstream side in the transport direction with respect to the side surface of the steel material S1, and has a predetermined angle in the direction opposite to the transport direction of the steel material S1. Tilt and spray descaling water. Moreover, the injection area | region of the descaling water injected from this nozzle 22 inclines with the predetermined | prescribed twist angle (illustration omitted) with respect to the width direction of steel materials S1. Incidentally, in the nozzle 22 for side indicates the angle of the nozzle with respect to the normal direction of the steel material side Sa and the angle of attack theta _2, the twisted angle indicates an angle of the injection region of the descaling water to the thickness direction of the steel material S1 ing.

  Here, in order to avoid the collision of the descaling water as described above (see FIGS. 1A and 1B), the descaling apparatus 1 includes a nozzle 22 for the side surface as shown in FIG. The descaling water is sprayed so as not to overlap with the spray area of the descaling water sprayed from the lower surface nozzle 12 (not shown).

  That is, as shown in FIG. 2, the descaling apparatus 1 is a position on the side surface of the bottom descaling header 11 that is a predetermined distance away from the outermost nozzle 12 in the bottom descaling header 11 in the width direction of the steel material S <b> 1. In addition, a header position adjusting means 23 protruding in the length direction of the steel material S1, that is, the upstream side in the transport direction is installed. The side descaling header 21 is installed at the tip of the header position adjusting means 23, and the nozzle 22 injects descaling water toward the upstream side in the transport direction of the steel material S1 (the direction opposite to the transport direction). Is configured to do.

  As described above, in the descaling apparatus 1, the lower surface nozzle 12 and the side surface nozzle 22 each eject the descaling water in the same direction, but the nozzle 12 is provided with the header position adjusting means 23. And the nozzle 22 are installed at positions distant from each other in the conveying direction of the steel material S1, and the spray areas of the descaling water of both nozzles do not overlap. Note that the specific length of the header position adjusting means 23, that is, the position on the upstream side in the conveying direction of the steel material S1, where the side descaling header 21 is installed is determined by, for example, the descaling water by the nozzle 12 for the lower surface. This can be determined experimentally from the injection region, the assumed width of the steel material S1, and the like.

  The descaling apparatus 1 having the above-described configuration is installed by shifting the side descaling header 21 to the upstream side in the transport direction with respect to the nozzle 12 for the lower surface via the header position adjusting unit 23. By preventing the descaling water sprayed from the nozzle 12 and the side nozzle 22 from colliding with each other on the path until the steel material S1 is collided, it is possible to prevent the descaling ability from being lowered. Therefore, according to the descaling apparatus 1, the scale of the steel material side surface Sa can be surely removed, and the high-quality steel material S1 with less scale wrinkles can be secured.

  Although not shown in FIG. 2, the descaling water sprayed from the top nozzle and the side nozzle 22 by installing the side descaling header 21 at the tip of the header position adjusting means 23, respectively. However, they do not collide with each other on the path until they collide with the steel material S1.

[Second Embodiment]
In the descaling apparatus 1 according to the first embodiment described above, by using the header position adjusting means 23, the side descaling header 21 is shifted from the nozzle 12 for the lower surface in the upstream in the transport direction. The descaling water from each nozzle is prevented from colliding, but other configurations such as shown in FIG. Hereinafter, the configuration of the descaling apparatus 1A according to the second embodiment of the present invention will be described in detail. In FIG. 3 also, the top-side descaling header and its nozzle are not shown.

  As shown in FIG. 3, the descaling apparatus 1A includes an upper surface descaling header, an upper surface descaling nozzle, a lower surface descaling header 11, a nozzle 12, a side surface descaling header 21A, and a side surface descaling header. The scaling nozzle 22A (hereinafter simply referred to as the nozzle 22A) is the same as the descaling apparatus 1 described above, but differs in that the header position adjusting means 23 is not provided.

  As shown in FIG. 3, the side descaling header 21 </ b> A in the present embodiment is predetermined in the width direction of the steel material S <b> 1 from the outermost nozzle 12 in the bottom descaling header 11 at the top. It is installed at a distance. And the nozzle 22A in this embodiment is comprised so that descaling water may be injected toward the downstream (same direction as a conveyance direction) of the conveyance direction of steel materials S1.

  As described above, in the descaling apparatus 1A, the side nozzle 22A is installed on the lower surface descaling header 11, but the nozzle 22A is in a direction different from the injection direction of the lower surface nozzle 12, that is, conveying the steel material S1. The descaling water is jetted downstream in the direction (the same direction as the transport direction). Thereby, the spray area | regions of the descaling water of both nozzles do not overlap.

  In the descaling apparatus 1A having the above-described configuration, the descaling water is jetted in different directions between the lower surface nozzle 12 and the side surface nozzle 22A so that they do not collide with each other on the path until they collide with the steel material S1. By doing so, a decrease in descaling capability can be prevented. Therefore, the scale of the steel material side surface Sa can be surely removed, and the high-quality steel material S1 with less scale wrinkles can be secured. Furthermore, according to the descaling apparatus 1A, the side surface descaling header 21A is installed on the bottom surface descaling header 11, so that the equipment cost can be reduced.

  Although not shown in FIG. 3, by configuring the side descaling header 21 </ b> A as described above, the descaling water sprayed from the top nozzle and the side nozzle 22 </ b> A is also used for the steel material S <b> 1. Will not collide with each other on the path until they collide with each other. Further, for example, the same effect can be achieved by installing the side descaling header 21A on the top descaling header and adopting the above-described configuration.

  Further, since the descaling device 1A injects the descaling water from the side nozzle 22A in the same direction as the conveying direction of the steel material S1, the scale removed from the steel material side surface Sa is placed on the upper surface of the steel material S1 again. Is also envisaged. Therefore, it is preferable to descale the upper surface of the steel material S1 again after descaling the upper and lower surfaces of the steel material S1 and the steel material side surface Sa in the descaling apparatus 1A assuming such a situation. In this case, the descaling apparatus 1A is opposite to the conveying direction of the steel material S1 with respect to the upper surface of the steel material S1 until it is rolled after jetting the descaling water from the side nozzle 22A to the steel material side surface Sa. The descaling water is sprayed at a predetermined angle in the direction. Thereby, the scale mounted again on the steel material S1 upper surface can be removed, and possibility that it will become a scale flaw in a subsequent rolling process can be reduced.

  In addition, as a method of descaling the upper surface of the steel material S1 again, a method of descaling by separately providing a descaling device for descaling the upper surface on the downstream side in the transport direction of the descaling device 1A, or hot rolled steel material A method of performing descaling again on the downstream side in the transport direction of the descaling apparatus 1A by using existing equipment such as a mill descaling apparatus installed before and after the rolling mill of No. 1 is included.

  Hereinafter, the present invention will be described more specifically with reference to examples. In this example, the descaling of the steel material surface was performed based on the method according to the present invention and the prior art, and the effects were compared.

  Specifically, in this example, a steel material having a width of 2.1 m, a length of 4 m, and a thickness of 250 mm heated in a heating furnace was descaled and then rolled to a thickness of 150 mm using only a horizontal roll. Then, the scale on the surface of the steel material was removed by shot blasting after rolling, and a depth gauge was used to determine how many scale ridges having a depth of 1 mm or more by being pushed into the steel material per 1 m of the steel material length. In the present example, a descaling device capable of descaling a steel material having a width of 2.5 m at the maximum was used, and the descaling of a steel material having a width of 0.4 m smaller than the maximum width was performed.

The descaling conditions for the upper and lower surfaces of the steel material are as follows: in each of the examples and comparative examples, the angle of attack 15 ° upstream of the nozzle conveyance direction, the twist angle 10 ° of each nozzle, the injection pressure of descaling water 15 MPa, the steel material The linear distance from the nozzle to the nozzle was 155 mm, the amount of water per 1 m of the steel material was 0.9 m ³ / min, and the conveying speed of the steel material was 1 m / s.

  The descaling conditions for the steel material side were changed for each of the examples and comparative examples. Table 1 shows the descaling conditions and the descaling results for the steel material side surfaces in the examples and comparative examples. In Table 1, the descaling of the steel material side surface is partially abbreviated as “side face deske”, and the descaling of the upper surface of the steel material is indicated as “upper face deske”.

In Example 1, assuming the configuration of the first embodiment (see FIG. 2), the side-side descaling header is installed on the bottom-side descaling header via the header position adjusting means, and the side-side descaling header is provided. Was installed 300 mm away from the upstream side in the transport direction. Further, with respect to the side nozzle, the angle of attack to the upstream side in the transport direction was 15 °, the twist angle was 10 °, and the amount of water was 0.9 m ³ / min per 1 m width of the steel material. And in Example 1, after descaling the steel material side surface, the upper surface of the steel material was descaled again. As a result, the number of scale creases per 1 m length of the steel material in Example 1 was 0.8, and the generation of scale creases could be greatly reduced.

In Example 2, assuming the modified example of the configuration of the second embodiment (see FIG. 3), the side-side descaling header is installed in the top-side descaling header. Further, with respect to the nozzle for the side surface, the angle of attack to the downstream side in the conveying direction was −15 °, the twist angle was 10 °, and the water amount was 0.9 m ³ / min per 1 m width of the steel material. As a result, the number of scale wrinkles per 1 m length of the steel material in Example 2 was 1.3, and the generation of scale wrinkles could be greatly reduced.

In Example 3, assuming the configuration of the above-described second embodiment (see FIG. 3), the side-side descaling header was installed in the bottom-side descaling header. Further, with respect to the nozzle for the side surface, the angle of attack to the downstream side in the transport direction is −10 °, the twist angle is 10 °, and the water amount is 0.9 m ³ / min per 1 m width of the steel material. As a result, the number of scale wrinkles per 1 m length of the steel material in Example 3 was 1.1, and the generation of scale wrinkles could be greatly reduced.

In Example 4, assuming that the configuration of the second embodiment (see FIG. 3) is modified, the side-side descaling header is installed in the top-side descaling header. Further, with respect to the nozzle for the side surface, the angle of attack to the downstream side in the conveying direction was −15 °, the twist angle was 10 °, and the water amount was 0.9 m ³ / min per 1 m width of the steel material. And in Example 4, after descaling the steel material side surface, the upper surface of the steel material was descaled again. As a result, the number of scale wrinkles per 1 m of steel material length in Example 4 was 0.5, and generation of scale wrinkles could be further reduced as compared with Example 2.

In Example 5, assuming the configuration of the above-described second embodiment (see FIG. 3), the side-side descaling header was installed in the bottom-side descaling header. Further, with respect to the nozzle for the side surface, the angle of attack to the downstream side in the transport direction is −10 °, the twist angle is 10 °, and the water amount is 0.9 m ³ / min per 1 m width of the steel material. And in Example 5, after descaling the steel material side surface, the upper surface of the steel material was descaled again. As a result, the number of scale creases per 1 m length of the steel material in Example 5 was 0.3, and generation of scale creases could be further reduced as compared with Example 3.

  In Comparative Example 1, the descaling of the steel material side surface was not performed, the descaling was performed only on the upper and lower surfaces, and then rolling was performed. In Comparative Example 1, since the descaling of the steel material side surface itself was not performed, a large amount of scale fell from the steel material side surface to the periphery of the rolling mill in the first pass of rolling. As a result, the number of scale ridges per 1 m of steel length in Comparative Example 1 was 18.

In Comparative Example 2, assuming the configuration of the descaling apparatus 101A (see FIGS. 1A and 1B), the side descaling header is installed in the bottom descaling header. Further, with respect to the side nozzle, the angle of attack to the upstream side in the transport direction was 15 °, the twist angle was 10 °, and the amount of water was 0.9 m ³ / min per 1 m width of the steel material. In Comparative Example 2, since the side nozzle is directed upstream in the steel conveying direction in the same manner as the top nozzle, the side descaling water and the bottom descaling water collide before reaching the steel. did. Thereby, since the rolling was performed with the scale remaining on the side surface of the steel material, a large amount of scale dropped from the side surface of the steel material to the periphery of the rolling mill in the first pass of rolling. As a result, the number of scale ridges per 1 m of steel material in Comparative Example 2 was 11.

In Comparative Example 3, assuming the configuration of the descaling apparatus 101 (see FIGS. 4A and 4B) proposed in Patent Document 4 above, 750 from the center of the width among the descaling nozzle for the upper surface and the descaling nozzle for the lower surface. The nozzle at ˜1200 mm was sprayed with an inclination of 15 ° toward the center in the width direction. Therefore, the amount of water sprayed on the side surface of the steel material was only 0.09 m ³ / min in terms of the amount of water per meter. For this reason, rolling was performed with the scale remaining on the side surface of the steel material, so that a large amount of scale fell from the side surface of the steel material to the periphery of the rolling mill in the first pass of rolling. As a result, the number of scale ridges per 1 m of the steel material in Comparative Example 3 was 7.

  From the above results, in the descaling apparatus and descaling method according to the present invention, the number of scale rods each having a depth of 1 mm or more per 1 m of steel length is about one, and the scale is compared with the prior art. It can be seen that the generation of soot can be effectively prevented.

  As described above, the hot-rolled steel material descaling method and descaling apparatus, the hot-rolled steel material manufacturing method and the manufacturing apparatus according to the present invention have been specifically described with reference to embodiments and examples for carrying out the invention. The gist of the invention is not limited to these descriptions, but should be broadly interpreted based on the description of the scope of claims. Needless to say, various changes and modifications based on these descriptions are also included in the spirit of the present invention.

  For example, in the descaling apparatus 1 described above, the header position adjusting means 23 is installed on the bottom descaling header 11 so as to protrude upstream in the transport direction, as shown in FIG. You may install in the descaling header 11 for lower surfaces so that it may protrude downstream. In this case, the descaling water is jetted toward the downstream side in the conveying direction of the steel material S1 by the nozzle 22 installed at the tip of the header position adjusting means 23.

  Further, in the descaling apparatus 1 described above, the header position adjusting means 23 is installed in the lower surface descaling header 11 as shown in FIG. 2, but it may be installed in the upper surface descaling header, for example. Absent. In this case, the header position adjusting means 23 is installed on the side surface of the top descaling header at a position away from the outermost nozzle in the top descaling header by a predetermined distance in the width direction of the steel material S1. And the descaling header 21 for side surfaces and the nozzle 22 are installed in the descaling header for upper surface via the header position adjustment means 23, and descaling water is injected toward the upstream or downstream side of the conveyance direction of steel S1. .

  Further, in the descaling apparatus 1A described above, it is preferable that the upper surface of the steel material S1 is descaled after the upper and lower surfaces of the steel material S1 and the steel material side surface Sa are descaled. After descaling the upper and lower surfaces and the steel material side surface Sa, the upper surface of the steel material S1 may be descaled again by another descaling device, a mill descaling device, or the like. Thereby, even if it is a case where a scale has rested on steel material S1 upper surface after descaling upper and lower surfaces and steel material side surface Sa of steel material S1, it can remove reliably.

  In addition, the descaling method using the descaling devices 1 and 1A and the descaling devices 1 and 1A described above is performed by using a hot rolled steel manufacturing apparatus including the descaling devices 1 and 1A and the descaling method. The present invention can also be applied to a method of manufacturing a hot rolled steel material that performs scaling.

1, 1A, 101, 101A Descaling device 11, 111A Descaling header for lower surface 12, 112A Descaling nozzle for lower surface (nozzle)
21, 121A Side scaling header 22, 122A Side scaling nozzle (nozzle)
23 Header position adjusting means 131, 131A Descaling header for upper surface 132A Descaling nozzle for upper surface (nozzle)
132a, 132b Descaling nozzle S1, S2 Steel material Sa Steel material side surface θ ₁ twist angle θ ₂ angle of attack

Claims (7)

A method for descaling hot rolled steel that removes the scale generated during the heat treatment of the steel before rolling,
A descaling header for the upper surface and a descaling header for the lower surface are installed in the width direction of the steel material, and descaling is performed on the upper and lower surfaces of the steel material from nozzles respectively attached to the descaling header for the upper surface and the descaling header for the lower surface. While jetting water,
A descaling header for a side surface is installed on either the descaling header for the upper surface or the descaling header for the lower surface, and the descaling water is sprayed to the side surface of the steel material from a nozzle attached to the descaling header for the side surface. And
The descaling water is sprayed from the nozzles of the side descaling header so as not to overlap with the spray areas of the descaling water sprayed from the nozzles of the top descaling header and the bottom descaling header. A method for descaling hot rolled steel. After spraying the descaling water from the nozzle of the side descaling header to the side surface of the steel material and before rolling, from the nozzle attached to the descaling header for the top surface to the top surface of the steel material Te, descaling method of hot rolling steel according to claim 1, characterized in that injecting the pre Symbol descaling water again. A hot-rolled steel descaling device that removes the scale generated during the heat treatment of the steel before rolling,
A top-side descaling header and a bottom-side descaling header, which are installed in the width direction of the steel material, and nozzles for injecting descaling water onto the top and bottom surfaces of the steel material, respectively;
A side descaling header installed on either the top surface descaling header or the bottom surface descaling header, to which a nozzle for injecting the descaling water is attached to the side surface of the steel material,
The nozzle of the side descaling header is sprayed with the descaling water so as not to overlap the spray area of the descaling water sprayed from the nozzle of the top descaling header and the nozzle of the bottom descaling header. A hot-rolled steel descaling apparatus characterized by: A plurality of nozzles for the descaling header for the upper surface and nozzles for the descaling header for the lower surface are arranged in the width direction of the steel material, and spray the descaling water toward the upstream side in the transport direction of the steel material,
Predetermined in the width direction of the steel material from the outermost nozzle in the upper surface descaling header or the outermost nozzle in the lower surface descaling header on the side surface of the upper surface descaling header or the lower surface descaling header Provided with a header position adjusting means that is installed at a distance apart and protrudes in the length direction of the steel material;
The side descaling header is installed at the tip of the header position adjusting means,
The hot-rolled steel descaling apparatus according to claim 3, wherein the nozzle of the descaling header for the side surface injects the descaling water toward an upstream side or a downstream side in a conveyance direction of the steel material. . A plurality of nozzles for the descaling header for the upper surface and nozzles for the descaling header for the lower surface are arranged in the width direction of the steel material, and spray the descaling water toward the upstream side in the transport direction of the steel material,
The side-side descaling header is the outermost nozzle in the upper surface descaling header or the outermost nozzle in the lower surface descaling header at the lower part of the upper surface descaling header or the upper part of the lower surface descaling header. Is installed at a position away from the steel material by a predetermined distance in the width direction,
The hot-rolled steel descaling apparatus according to claim 3, wherein the nozzle of the side descaling header sprays the descaling water toward the downstream side in the transport direction of the steel material.   Descaling is performed using the descaling method of Claim 1 or Claim 2, The manufacturing method of the hot-rolled steel materials characterized by the above-mentioned.   A hot-rolled steel manufacturing apparatus comprising the descaling apparatus according to any one of claims 3 to 5.

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