Title of the invention : Apparatus for removing foreign matter from roll surface, method for removing foreign matter from roll surface, and method for manufacturing steel strip
Technical field
[0001]
The present disclosure relates to a roll surface foreign matter removing device, a roll surface foreign matter removing method, and a steel strip manufacturing method.
Background technology
[0002]
Rolls for transporting steel strips are provided in heating furnaces such as continuous annealing furnaces in the steel plate manufacturing process. Various treatments are required for the surfaces of such rolls. For example, in Japanese Patent No. 3932947, foreign matter adhering to a transport roll in a heat treatment furnace is removed by a foreign matter scraping means that brings a part of a thin member into surface contact with the roll, and the roll surface is cleaned. technique is described.
[0003]
In addition, Japanese Patent Application Laid-Open No. 2002-120153 describes a technique of plastically deforming the surface layer by performing shot peening on the welded portion of the shroud, which is a structural member in the reactor pressure vessel. Specifically, by striking particles such as steel balls against the surface layer of the weld, the tensile residual stress remaining in the surface layer is converted into compressive residual stress.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0004]
Japanese Patent No. 3932947 relates to foreign matter scraping means in a roll surface conditioning device that is exposed to a high temperature environment in a heat treatment furnace for a long time. Foreign matter adhering to the roll is removed. Since foreign matter is removed during sheet threading, there is a problem that the removed foreign matter adheres to the steel sheet and causes flaws.
[0005]
In addition, in Japanese Patent No. 3932947, no consideration is given to periodic repairs and maintenance performed on the transport rolls while the heating furnace is stopped. For example, no consideration is given to the removal of foreign matter for recovering the surface roughness of the transport roll. Moreover, even if the technique disclosed in Japanese Patent No. 3932947 is applied to periodic repairs, the foreign matter scraping means removes the foreign matter adhering to the roll surface, and rather flattens the roll surface.
[0006]
Further, if the technique of JP-A-2002-120153 is applied to the removal of foreign matter from the transport roll, the shape of the surface is deformed by striking the surface of the transport roll with particles, and compressive residual stress is generated on the surface. It is possible to let However, Japanese Patent Application Laid-Open No. 2002-120153 does not consider effectively removing foreign matter from the surface of the transport roll. For this reason, even if particles are hit onto the surface of the transport roll using the technique disclosed in Japanese Patent Laid-Open No. 2002-120153, it is difficult to effectively remove the foreign substances on the roll surface.
[0007]
Further, in the case of Japanese Patent Application Laid-Open No. 2002-120153, since the particles are hit so as to promote the deformation of the surface shape of the transport roll, the shape of the hit roll surface is changed to the original shape before the foreign matter adheres. There is a high possibility that it will be deformed significantly to the extent that it will not restore its shape. For this reason, there is a concern that the steel strip may be conveyed improperly due to the influence of the conveying rolls that are greatly deformed after the particles are struck.
[0008]
Therefore, the present disclosure has been made in view of the above problems. Another object of the present invention is to provide an apparatus for removing foreign matter from a roll surface, a method for removing foreign matter from a roll surface, and a method for manufacturing a steel strip.
Means to solve problems
[0009]
In order to solve the above problems, according to one aspect of the present disclosure, an injection section that injects a blast material onto the surface of a roll that conveys a steel strip in a heating furnace, and a recovery section that recovers the blast material. and a pressing part for pressing the blasting part toward the surface of the roll.
[0010]
In order to solve the above problems, according to another aspect of the present disclosure, a step of pressing a blasting section of the apparatus for removing foreign matter from the roll surface against the roll surface, ejecting a projection material from within the blasting section, and recovering the blast material in the blasting section.
[0011]
In order to solve the above problems, according to another aspect of the present disclosure, a step of removing foreign matter on the surface of a roll provided in a heating furnace by the method for removing foreign matter on the surface of the roll; and passing the steel strip through a heating furnace for heat treatment.
Effect of the invention
[0012]
As described above, according to the present disclosure, an apparatus for removing foreign matter on a roll surface, a method for removing foreign matter on a roll surface, and a method for removing foreign matter on a roll surface, which can easily remove foreign matter on the surface of a transport roll provided in a heating furnace. and a method for manufacturing a steel strip.
Brief description of the drawing
[0013]
1] Fig. 1 is a schematic diagram showing a configuration example of part of an operating line provided with a heating furnace according to an embodiment of the present disclosure. [Fig.
[Fig. 2] Fig. 2 is a schematic diagram showing a configuration example of a part of an operation line provided with a heating furnace according to the present embodiment.
3 is a schematic diagram showing a configuration example of a device for removing foreign matter from a roll surface according to the present embodiment; FIG.
4 is a top view showing a configuration example of the device for removing foreign matter from the roll surface according to the present embodiment; FIG.
5 is a schematic diagram for explaining a configuration example of a blasting section according to the present embodiment; FIG.
6 is a schematic diagram for explaining the projection angle of the projection material when foreign matter is removed by the blasting section according to the present embodiment; FIG.
7A is a schematic diagram of a roll surface for explaining how foreign substances are removed by the blasting section according to the present embodiment. FIG.
7B is a schematic diagram of a roll surface for explaining how foreign substances are removed by the blasting section according to the present embodiment. FIG.
7C is a schematic diagram of a roll surface for explaining how foreign substances are removed by the blasting section according to the present embodiment. FIG.
8 is a flow chart of a method for removing foreign matter from a roll surface according to the present embodiment; FIG.
9 is a flow chart of a method for manufacturing a steel strip according to the present embodiment; FIG.
10 is a graph showing the amount of Mn oxide removed from roll surfaces in Examples and Comparative Examples. FIG.
MODE FOR CARRYING OUT THE INVENTION
[0014]
Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description. In addition, in the following description of the drawings, the same or similar reference numerals are given to the same parts and similar parts. However, the relationship between the thickness and the plane dimension in the drawings, the ratio of the thickness of each device and each member, etc. are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. In addition, there are portions with different dimensional relationships and ratios between the drawings.
[0015]
<1. Heating furnace>
First, a heating furnace 10 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic diagram showing a configuration example of part of an operation line provided with a heating furnace 10A according to this embodiment. Moreover, FIG. 2 is a schematic diagram showing a configuration example of a part of the operating line provided with the heating furnace 10B according to the present embodiment.
[0016]
As shown in FIG. 1, the heating furnace 10A is provided in, for example, a continuous galvanizing line (CGL) for continuously immersing the steel strip 1 in a plating bath 13A and plating the surface of the steel strip. It is a continuous annealing furnace. The heating furnace 10A anneals the steel strip 1 after cold rolling. 10 A of heating furnaces are not specifically limited, For example, it is a continuous heating furnace which can heat-process continuously with respect to the steel strip 1. As shown in FIG.
[0017]
In addition, as shown in FIG. 1, the plating treatment equipment 13 is provided downstream of the heating furnace 10A in the conveying direction, and performs alloying hot-dip galvanizing treatment on the steel strip 1. The conveying direction is the direction in which the steel strip 1 is directed from the right side to the left side in FIG. The plating equipment 13 immerses the steel strip 1 in a plating bath 13A filled with the molten metal M to continuously adhere the molten metal M to the surface of the steel strip 1, and then apply the molten metal M to a predetermined amount. It is a facility that adjusts the basis weight and alloys the plating film.
[0018]
As shown in FIG. 1, a roll 11 for conveying the steel strip 1 is provided inside the heating furnace 10A. The roll 11 is a so-called hearth roll, is rotated by a rotational force from a roll drive source (not shown), and conveys the steel strip 1 within the heating furnace 10A.
[0019]
Further, as shown in FIG. 2, the heating furnace 10B is a continuous annealing facility (CAPL; Continuous Annealing and Processing Line (C.A.P.L. is a registered trademark)) provided in a part of the rolling process. is. The heating furnace 10B anneals the steel strip 1 after cold rolling. The heating furnace 10B is not particularly limited, and is, for example, a vertical heating furnace capable of continuously subjecting the steel strip 1 to heat treatment such as overaging treatment.
[0020]
As shown in FIG. 2, a roll 11 for conveying the steel strip 1 is provided inside the heating furnace 10B. Moreover, the roll 11 changes the conveying direction of the steel strip 1 in the vertical direction in the heating furnace 10B which is a vertical heating furnace. The roll 11 is a so-called hearth roll, and is rotated by a rotational force from a roll driving source (not shown). In the following description, heating furnaces 10A and 10B may be simply referred to as heating furnace 10 in some cases.
[0021]
The rolls 11 used in the heating furnace 10 as described above have a predetermined degree of roughness (that is, surface roughness) in order to convey the steel strip 1 . As a result, the frictional force between the roll 11 and the steel strip 1 is ensured, and the meandering of the steel strip 1 during threading is suppressed. However, the roughness of the roll surface may become smaller than the predetermined value due to abrasion due to use of the roll 11 for a long period of time, oxide formation on the roll surface, or the like. As a result, the steel strip 1 tends to meander during threading, which may affect operational stability.
[0022]
In particular, when the steel strip 1 is made of high-strength steel, oxides may be formed on the roll surface due to the components in the steel. Specifically, manganese (Mn), which is a component in steel, forms a film of Mn oxide on the surface of the roll. For this reason, the roughness of the roll surface becomes smaller than a predetermined value, and the frictional force between the steel strip 1 and the roll 11 decreases, which may cause meandering of the steel strip 1 or the like. In particular, when the steel strip 1 is a high-tensile steel having a tensile strength (TS) of 780 MPa or more, the phenomenon described above is likely to occur.
[0023]
<2. Foreign Matter Removal Device for Roll Surface>
Therefore, as a result of intensive studies by the present disclosers, the present disclosers have come up with the idea of ​​performing foreign matter removal on the roll 11 provided in the heating furnace 10 to recover the roughness. The foreign matter removal process increases the surface roughness of the roll 11 and restores the roughness. Hereinafter, a roll surface foreign matter removing apparatus 100 according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a schematic diagram showing a configuration example of the roll surface foreign matter removing apparatus 100 according to the present embodiment.
[0024]
As shown in FIG. 3, the roll surface foreign matter removing device 100 is a device that performs processing for recovering the roughness of the roll surface 11A. A roll surface foreign matter removing apparatus 100 has a part of its configuration (that is, the portion included in the area surrounded by the two-dot chain line shown in FIG. 3) in the heating furnace 10, and removes foreign matter from the roll surface 11A. remove. For example, the apparatus 100 for removing foreign matter on the roll surface is installed in the heating furnace 10 whose operation is stopped due to periodic maintenance or the like, and is removed from the heating furnace 10 during normal operation. That is, the roll surface foreign matter removing device 100 is temporarily installed in the heating furnace 10 and can be removed after the foreign matter removing operation is completed.
[0025]
When a plurality of rolls 11 are provided in the heating furnace 10, the roll surface foreign matter removing device 100 removes foreign matter from each roll 11 in sequence. That is, the roll surface foreign matter removing device 100 removes foreign matter from one roll 11 in the heating furnace 10 .After the removal, the roll surface foreign matter removing device 100 is once detached, moved, and then reattached to a position corresponding to another roll 11 . Thereafter, the roll surface foreign matter removing device 100 removes foreign matter from another roll 11 . A plurality of roll surface foreign matter removing apparatuses 100 may be installed in the heating furnace 10 .
[0026]
(Blast processing part)
Specifically, as shown in FIG. The blast processing unit 110 roughens the roll surface 11A by performing a blast processing on the roll surface 11A and removing foreign matter from the roll surface 11A. Specifically, the blast processing section 110 includes an injection section 111 that injects a blast material corresponding to the blast material P, which will be described later in FIG. As an example, the injection unit 111 injects the projection material together with a gas corresponding to the gas G described later with reference to FIG. 5 . As a result, the projection material collides with the roll surface 11A. In addition, as an example, the collecting unit 113 collects the projection material by sucking it together with the gas.
[0027]
An example of the projection material is a metal oxide polygonal powder, particularly an aluminum oxide powder (that is, alumina particles). Aluminum oxide is chemically stable, and even if it remains in the heating furnace, its influence on the operation of the heating furnace is suppressed. In addition, since alumina powder, which is commonly used as an abrasive, is relatively inexpensive, the cost required for removing foreign matter can be reduced.
[0028]
Another example of a polygonal metal oxide projection material is zirconium oxide (that is, zirconia) powder. Further, another example of the blasting material is silicon carbide (SiC) powder. An example of the hardness of the projection material is about 2000 to 3000 in terms of Vickers hardness. An example of the particle size of the projection material is about #30 to #220.
[0029]
Compressed air is an example of the gas that is injected together with the projectile. The pressure during injection is, for example, about 0.2 MPa to 0.7 MPa. In addition, in this embodiment, the range of the injection pressure of the compressed air is preferably 0.2 MPa or more and 0.5 MPa or less. By setting the injection pressure range to 0.2 MPa or more and 0.5 MPa or less, the oxide film C, which is a foreign matter, can be efficiently removed.
[0030]
When the injection pressure is less than 0.2 MPa, the pressure is so small that the injected blast material P is less likely to bite into the oxide film C, and as a result, the oxide film C cannot be sufficiently removed. Further, when the injection pressure exceeds 0.5 MPa, the injected projection material P may bite into the roll surface 11A and remain on the roll surface 11A. For this reason, there is a possibility that the blast material P that has bitten into the steel sheet may cause a steel plate flaw. In the present embodiment in which the oxide film C is Mn oxide, the Mn oxide is sufficiently removed even when the injection pressure is a relatively low value within the range of 0.2 MPa or more and 0.5 MPa or less. I found it possible.
[0031]
The projection material and gas injected from the injection part 111 are supplied from outside the furnace through the hose 130 shown in FIG. Specifically, the shot material is supplied from outside the furnace through a shot material supply hose 131 . Also, the gas is supplied from outside the furnace via the gas supply hose 132 . Although the details will be described later, the ends of the projection material supply hose 131 and the gas supply hose 132 outside the furnace are connected to a projection material supply source and a gas supply source, respectively. Also, the shot material and gas recovered by the recovery unit 113 are discharged out of the furnace through the discharge hose 133 .
[0032]
(pressing part)
The pressing part 120 presses the blasting part 110 toward the surface 11A of the roll. Although the details will be described later, by pressing the blasting section 110 toward the roll surface 11A, the inner surface of the blasting section 110 and the roll surface 11A form a closed space. This prevents the shot material injected from the injection part 111 from scattering in the furnace. An example of the pressing portion 120 is an air cylinder 121 .
[0033]
The apparatus 100 for removing foreign matter from the roll surface may further have a link arm 101 for arranging the blasting section 110 and the pressing section 120 at predetermined positions with respect to the roll surface 11A. A link arm 101 is an arm-like member connected by one or more joint structures. The link arm 101 allows the blast processing section 110 and the pressing section 120 to be arranged at predetermined positions with respect to the roll surface 11A even when the diameters of the plurality of rolls 11 provided in the heating furnace 10 are different. A blasting part 110 and a pressing part 120 are attached to one end 101A of the link arm 101 via a bracket. The other end portion 101B of the link arm 101 is attached to the main body portion 103 of the roll surface foreign matter removing apparatus 100, which will be described later.
[0034]
(Detection unit)
The apparatus 100 for removing foreign matter from the roll surface further includes a detection section 140 that detects the distance between the blast processing section 110 and the roll surface 11A. The detector 140 is positioned relative to the roll surface 11A via a bracket attached to one end 101A of the link arm. The detector 140 measures the distance to the roll surface 11A. An example of the detection unit 140 is a laser sensor.
[0035]
(roll rotation mechanism)
The roll surface foreign matter removing device 100 may further include a roll rotation mechanism 150 that rotates the roll 11 . In particular, the roll rotation mechanism 150 rotates the rolls 11 in a state in which no rotational force is supplied to the rolls 11 for conveying the steel strip 1 . As an example, the roll rotation mechanism 150 rotates the roll 11 by rotating the rotating portion 151 while the outer peripheral surface 151A is in contact with the surface 11A of the roll.
[0036]
As shown in FIG. 4, the rotating part 151 is, for example, a small roll, and is rotated by being driven by a drive source 153 such as a motor. By performing blasting while rotating the roll 11 , it becomes easy to remove foreign matter from the surface of the roll 11 along the circumferential direction of the roll 11 . Further, as an example, even if the heating furnace 10 is under regular maintenance and the power supply to the heating furnace 10 and peripheral equipment is stopped, the roll drive source used when conveying the steel strip 1 cannot be used. Roll 11 can be rotated. As a result, power supply to the heating furnace 10 and peripheral equipment becomes unnecessary, and surface foreign matter removal along the circumferential direction of the roll 11 can be achieved by the roll surface foreign matter removing apparatus 100 having the roll rotation mechanism 150 alone.
[0037]
Further, the roll rotation mechanism 150 rotates the roll 11 by rotating the rotating portion 151 while the outer peripheral surface 151A is in contact with the roll surface 11A. That is, when rotating the roll 11, the roll rotation mechanism 150 can be configured simply, so that the device 100 for removing foreign matter on the roll surface can be made compact.
[0038]
Further, the roll surface foreign matter removing apparatus 100 may further include a main body 103 . Various components such as the blast processing unit 110 , the pressing unit 120 , and the roll rotation mechanism 150 are attached to the main unit 103 . Further, the apparatus 100 for removing foreign matter on the roll surface is installed in the heating furnace 10 via the main body 103 . Various components of the device 100 for removing foreign matter on the roll surface can be integrally attached to or removed from the heating furnace 10 by the main body 103, thereby improving workability.
[0039]
As an example, the body part 103 is a structure having a longitudinal direction along the axial direction of the roll 11 parallel to the X direction in FIG. As an example, the structure as the main body part 103 is attached to beam-like members provided along the conveying direction of the steel strip 1 in the heating furnace 10 at both ends in the longitudinal direction. Illustration of the beam-shaped member is omitted. As an example, the body part 103 is attached to a beam member of the heating furnace 10 via a fixing jig (not shown).
[0040]
Further, the apparatus 100 for removing foreign matter from the roll surface may have, outside the furnace, an air supply/exhaust system 160 that enables the blasting material collected by the collecting unit 113 to be reused. Specifically, the roll surface foreign matter removing apparatus 100 may include a collection tank 161 , a dust collector 163 , and a blower 165 . By exhausting the air through the blower 165, the insides of the exhaust hose 133, the collection tank 161, and the dust collector 163 become negative pressure with respect to the outside air. Therefore, the projection material recovered from the recovery unit 113 moves inside the discharge hose 133 to the recovery tank 161 .
[0041]
The projection material transferred to the collection tank 161 via the discharge hose 133 is separated from dust other than the projection material by centrifugal separation in the collection tank 161 . The selected projection material is supplied to the injection section 111 again through the projection material supply hose 131 . On the other hand, dust and the like separated from the projection material are collected by a dust collector 163 , and the gas cleaned by the dust collection is discharged from a blower 165 .
[0042]
In addition, the apparatus 100 for removing foreign matter from the roll surface has a gas supply source 167 outside the furnace. Gas having a predetermined pressure supplied from the gas supply source 167 is supplied to the injection section 111 via the gas supply hose 132 . The injection unit 111 injects the projection material together with the gas supplied from the gas supply source 167 . An example of the gas supply source 167 is an air supply facility in the factory.
[0043]
(moving mechanism)
FIG. 4 is a top view showing a configuration example of the roll surface foreign matter removing device 100 according to the present embodiment. As shown in FIG. 4, the apparatus 100 for removing foreign matter from the roll surface may have a moving mechanism 170 that moves the blasting section 110 along the axial direction of the roll 11 parallel to the X direction in FIG. . The moving mechanism 170 is capable of moving the blasting section 110 in the axial direction of the roll 11, at least in a region excluding the inclined portions of the ends in the axial direction (that is, the region W in FIG. 4). By moving the blasting section 110 along the axial direction of the roll 11, it is possible to remove foreign matter on the roll surface 11A over a wider range. In addition, since it is not necessary to provide a large number of blasting units 110 or widen the projection range, it is possible to reduce the size of the roll surface foreign matter removing apparatus 100 .
[0044]
An example of the moving mechanism 170 is a screw feed mechanism, as shown in FIG. Specifically, the moving mechanism 170 includes a screw feed mechanism 171 , a drive source 173 and a guide shaft 175 .
[0045]
The screw feed mechanism 171 includes a screw shaft 171A whose axial direction is along the direction of the rotation axis X1 of the roll 11, and support portions 171B that rotatably support both ends of the screw shaft 171A. Hereinafter, the direction of the rotation axis X1 is simply referred to as "the axial direction of the roll". In addition, the rotation axis X1 coincides with the axial direction of the roll 11 .
[0046]
The screw shaft 171A is a rod-shaped member having threads provided at a predetermined pitch on its outer peripheral surface. As shown in FIG. 4, the screw shaft 171A is threadedly inserted into the other end portion 101B of the link arm 101. As shown in FIG. A drive source 173 is connected to the end of the screw shaft 171A so that the drive source 173 rotates the screw shaft 171A. As a result, the blast processing section 110 is screw-fed and moved along the axial direction of the roll 11 by the rotation of the screw shaft 171A.
[0047]
The guide shaft 175 is a rod-shaped member provided along the axial direction of the roll 11 in parallel with the screw shaft 171A. Both ends of the guide shaft 175 are supported by the support portions 171B of the screw shaft 171A.
[0048]
In the above description, an example in which the moving mechanism 170 linearly moves the blast processing unit 110 along the axial direction of the roll 11 has been described, but the present disclosure is not limited to such an example. The moving mechanism 170 includes an axial component of the roll 11 in the moving direction of the blasting section 110.As an example, the moving mechanism 170 may move the blasting section 110 in a meandering or oblique manner.
[0049]
Next, the configuration of the blast processing unit 110 will be described in detail with reference to FIG. FIG. 5 is a schematic diagram for explaining a configuration example of the blast processing section 110. As shown in FIG. As shown in FIG. 5 , the blasting section 110 performs blasting on the roll surface 11A while being pressed by an air cylinder 121 as the pressing section 120 . In the blast processing section 110 , an injection section 111 is provided in the center of the blast processing section 110 and a collection section 113 is provided around the injection section 111 . That is, the projection material P ejected from the ejection portion 111 is recovered from the recovery portion 113 provided around the ejection portion 111 after colliding with the roll surface 11A.
[0050]
Specifically, as shown in FIG. 5 , the blasting section 110 has a double cylindrical shape 115 . That is, the blasting section 110 has a double cylindrical shape 115 composed of an inner cylindrical portion 115A and an outer cylindrical portion 115B surrounding the inner cylindrical portion 115A. As shown in FIG. 5 , in the blasting section 110 , the inner cylinder section 115A forms at least part of the injection section 111 and the outer cylinder section 115B forms at least part of the recovery section 113 . Here, the double cylinder shape 115 is a shape in which a double annular structure is at least partially formed by the inner cylinder portion 115A and the outer cylinder portion 115B in the blasting section 110 in a cross-sectional view. Point.

The scope of the claims
[Claim 1]
A blasting section that includes an injection section that injects blasting material onto the surface of the roll that conveys the steel strip in the heating furnace, and a recovery section that collects the blasting material;
a pressing portion that presses the blasting portion toward the surface of the roll;
A device for removing foreign matter from a roll surface.
[Claim 2]
The device for removing foreign matter from the roll surface according to claim 1, wherein the injection section is provided in the center of the blast processing section, and the recovery section is provided around the injection section.
[Claim 3]
The blasting part has a double cylinder shape consisting of an inner cylinder part and an outer cylinder part surrounding the inner cylinder part,
The device for removing foreign matter from a roll surface according to claim 1 or 2, wherein the inner cylinder portion is an injection portion and the outer cylinder portion is a recovery portion.
[Claim 4]
The device for removing foreign matter from the roll surface according to claim 3, wherein a flexible member is provided at the end of the outer cylindrical portion.
[Claim 5]
The apparatus for removing foreign matter from a roll surface according to any one of claims 1 to 4, further comprising a detection section that detects the distance between the blast processing section and the surface of the roll.
[Claim 6]
6. The method according to claim 5, wherein when the distance between the surface of the roll detected by the detection unit and the blasting unit reaches or exceeds a predetermined value, the injection unit stops injecting the projection material. A device for removing foreign matter from the roll surface.
[Claim 7]
The apparatus for removing foreign matter from a roll surface according to any one of claims 1 to 6, further comprising a moving mechanism for moving the blasting section along the axial direction of the roll.
[Claim 8]
The device for removing foreign matter from a roll surface according to any one of claims 1 to 7, further comprising a roll rotation mechanism that rotates the roll.
[Claim 9]
The injection part injects the projection material together with the gas,
The apparatus for removing foreign matter from a roll surface according to any one of claims 1 to 8, wherein the recovery unit recovers the projection material by sucking it together with the gas.
[Claim 10]
The injection unit injects the gas in a pressure range of 0.2 MPa or more and 0.5 MPa or less,
The device for removing foreign matter from the roll surface according to claim 9.
[Claim 11]
The injection unit projects the projection material at a projection angle of 80 degrees or more and 90 degrees or less with respect to the roll surface when viewed along the axial direction of the roll.
The device for removing foreign matter from the roll surface according to any one of claims 1 to 10.
[Claim 12]
The device for removing foreign matter from a roll surface according to any one of claims 1 to 11, wherein the blast material is alumina particles.
[Claim 13]
A step of pressing the blasting part of the device for removing foreign matter from the roll surface according to any one of claims 1 to 12 against the roll surface;
a step of injecting the projection material from within the blasting section and recovering the projection material within the blasting section;
A method for removing foreign matter on the roll surface, including
[Claim 14]
In the process of injecting the blasting material, after injecting the first blasting material having a first average particle diameter, the second blasting material having a second average particle diameter smaller than the first average particle diameter is injected. to inject,
The method for removing foreign matter from the roll surface according to claim 13.
[Claim 15]
A step of removing foreign matter on the surface of the roll provided in the heating furnace by the method for removing foreign matter on the surface of the roll according to claim 13;
A step of passing the steel strip through a heating furnace provided with the rolls and performing heat treatment;
A steel strip manufacturing method that includes
[Claim 16]
The removing step is performed while rotating the roll by applying a rotational force via a rotating mechanism that is in contact with the roll surface,
The method for manufacturing the steel strip according to claim 15.
[Claim 17]
The steel strip manufacturing method according to claim 15 or 16, wherein the steel strip is high-strength steel.