JP2015196886A - Wear resistant liner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a wear resistant liner while reducing the used amount of cemented carbide.SOLUTION: A wear resistant liner 1 is provided where cemented carbide 3 is embedded into a surface layer part of a base material 2. In the wear resistant liner 1, the cemented carbide 3 forms a cell structure in which cells 4 having a polygonal cross section and opening vertically with respect to a surface 1s of the wear resistant liner 1 are arranged continuously or discretely. The wear resistant liner 1 exhibits strength efficiently by the formation of the cell structure by the cemented carbide 3. Consequently, sufficient durability can be obtained by a smaller amount of cemented carbide 3 in comparison with conventional wear resistant liners. Self-lining effect by fine grains of a material brought into contact with the surface 1s can be expected by opening the cells 4 vertically with respect to the surface 1s.

Description

  The present invention relates to a wear-resistant liner, and more particularly to a wear-resistant liner installed on a chute for charging ore, lime, coke and the like.

  When ore, lime, coke, or the like is charged into a blast furnace, the charge falls through a vertical chute and is then charged into an arbitrary position in the blast furnace by a swivel chute. The swivel chute is provided with a liner for protecting the chute body from wear due to contact with the charge. However, since the wear of the liner due to the hard charge colliding with the surface of the liner or sliding down the surface of the liner, the liner must be frequently repaired or replaced. Thus, for example, as described in Patent Document 1, a wear-resistant liner in which cemented carbide alloy particles (tungsten carbide coarse particles) are embedded in a surface layer portion of a base material (high chromium cast steel) has been developed.

Japanese Patent Laid-Open No. 11-13114

  Here, an example of a conventional wear-resistant liner as described in Patent Document 1 is shown in FIG. FIG. 9A is a partial longitudinal sectional view of a conventional wear resistant liner 81, and FIG. 9B is a partial cross sectional view of the wear resistant liner 81. The relationship between (A) and (B) in FIG. 9 is indicated by a cutting line VA-VA and a cutting line VB-VB in the drawing. In the wear-resistant liner 81, cemented carbide particles 83 are embedded in the surface layer portion of the base material 82. Since the cemented carbide particles 83 harder than the base material 82 resist wear, durability can be improved as compared with, for example, a liner composed of only the base material.

  However, since the wear of the base material 82 proceeds in the portion other than the cemented carbide particles 83 in the surface layer portion, the cemented carbide particles 83 are gradually exposed from the base material 82. Since the cemented carbide particles 83 are substantially spherical, for example, when about half of the cemented carbide particles 83 are exposed from the base material 82, the cemented carbide particles 83 are likely to be lost due to impact or the like. Therefore, the frequency of repair and replacement is still high in the wear-resistant liner 81, and repair costs and replacement costs are high because the cemented carbide particles 83 are expensive. Therefore, as shown in FIG. 10, an abrasion resistant liner 91 obtained by improving the abrasion resistant liner 81 has been proposed.

  FIG. 10A is a partial vertical cross-sectional view of an improved conventional wear-resistant liner 91, and FIG. 10B is a partial cross-sectional view of the wear-resistant liner 91. The relationship between (A) and (B) in FIG. 10 is indicated by a cutting line in the figure as in FIG. In the wear-resistant liner 91, a cemented carbide pin 93 is embedded through the surface layer portion of the base material 92. As in the example of FIG. 9, the durability of the liner can be improved by the cemented carbide pin 93 harder than the base material 92 resisting wear. Further, since the cemented carbide pin 93 has a substantially cylindrical shape, even if it is exposed from the worn base material 92, it is difficult to be lost. However, since it is necessary to use many cemented carbides to form the cemented carbide pin 93, the wear resistant liner 91 is more expensive than the conventional wear resistant liner as shown in FIG.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is a novel and improved technique capable of improving durability while reducing the amount of cemented carbide used. It is to provide a wear resistant liner.

  In order to solve the above problems, according to one aspect of the present invention, there is provided an abrasion resistant liner in which a cemented carbide is embedded in a surface layer portion of a base material, and the cemented carbide is in contact with the surface of the abrasion resistant liner. A wear-resistant liner is provided, characterized in that cells open in the vertical direction form a cell structure arranged continuously or discretely.

  In such an abrasion-resistant liner, the cemented carbide forms a cell structure, and thereby exhibits strength efficiently. Therefore, sufficient durability can be obtained with a less amount of cemented carbide compared to the conventional one (for example, the wear resistant liner 91 shown in FIG. 10). In addition, since the cells are opened in the direction perpendicular to the surface of the wear resistant liner, the effect of cell flying by fine particles of the material can be expected.

  In the above wear-resistant liner, it is desirable that the diameter of the inscribed circle in the cross section of the cell is less than the average particle diameter of the material in contact with the surface of the wear-resistant liner. As a result, it is possible to prevent the coarse particles of the material from entering the cell and advance the wear of the base material, thereby improving the durability of the wear-resistant liner.

  In the above wear-resistant liner, it is desirable that the thickness of the cemented carbide member defining the cell is 1 mm or more. This can prevent the cemented carbide member from buckling due to the bending stress applied by the material collision.

  Further, in the above wear-resistant liner, the cells may have a hexagonal cross section, a quadrangular cross section, or a triangular cross section, and may form a continuously arranged honeycomb structure. The cross-sectional shape of the cell can be appropriately selected according to, for example, the formation process of the cell structure. Regardless of the cross-sectional shape, it is possible to obtain the effect of reducing the use amount of cemented carbide and improving the durability.

  In the wear resistant liner, a through hole may be formed in the cemented carbide member that defines the cell. In addition to further reducing the amount of the cemented carbide used by providing the through holes, it is easy to spread the base material over the entire cell structure when casting the base material into the cell.

  As described above, according to the present invention, durability can be improved while reducing the amount of cemented carbide used in the wear-resistant liner. Therefore, it is possible to achieve both a reduction in the cost of the wear-resistant liner and a longer life.

It is a figure showing the whole wear-resistant liner composition concerning one embodiment of the present invention. It is a figure which shows the variation of the cell structure in the abrasion-resistant liner shown in FIG. It is a figure which shows the variation of the cell structure in the abrasion-resistant liner shown in FIG. It is a figure which shows the variation of the cell structure in the abrasion-resistant liner shown in FIG. It is a figure which shows the variation of the cell structure in the abrasion-resistant liner shown in FIG. It is a figure which shows the variation of the cell structure in the abrasion-resistant liner shown in FIG. It is a figure which shows the example which provided the through-hole in the cemented carbide member which prescribes | regulates a cell in the abrasion-resistant liner shown in FIG. It is a figure for demonstrating the opening width of the cell and the thickness of a cemented carbide member in the abrasion-resistant liner which concerns on one Embodiment of this invention. It is a figure which shows the example of the conventional abrasion-resistant liner. It is a figure which shows another example of the conventional abrasion-resistant liner.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(overall structure)
First, with reference to FIG. 1, the whole structure of the abrasion-resistant liner which concerns on one Embodiment of this invention is demonstrated. The wear-resistant liner 1 is fixed to the inner side surface and the inner bottom surface of the chute body using bolts, for example, in a swiveling chute of a blast furnace, and protects the chute body from wear due to contact with charges such as ore, lime, and coke. To do. FIG. 1A is a partial longitudinal sectional view of the wear resistant liner 1, and FIG. 1B is a partial cross sectional view of the wear resistant liner 1. The relationship between (A) and (B) in FIG. 1 is indicated by a cutting line IA-IA and a cutting line IB-IB in the drawing. 1A and 1B show common xyz coordinate axes. According to this coordinate axis, the surface 1s of the wear-resistant liner 1 is parallel to the xy plane, and the z-axis is perpendicular to the surface 1s.

  In the wear-resistant liner 1, a cemented carbide 3 is embedded in the surface layer portion of the base material 2. For example, the base material 2 can be high chromium cast steel and the cemented carbide 3 can be tungsten carbide. Alternatively, for example, a hard material (superhard alloy) and a soft material (base material) may be used in combination from stainless steel, ceramics, fiber reinforced ceramics, various overlays, cermets, clad steels, and the like. Similar to the conventional wear-resistant liners 81 and 91 described above with reference to FIGS. 9 and 10, the wear-resistant liner 1 also has a surface layer portion embedded with a cemented carbide 3 harder than the base material 2. It is possible to suppress wear of the base material 2 when the entry collides with the surface 1s or when the charge slides down on the surface 1s. Further, in the wear-resistant liner 1, the cemented carbide 3 exhibits strength efficiently by forming a cell structure that opens in a direction perpendicular to the surface of the wear-resistant liner. Sufficient durability can be obtained with a small amount of cemented carbide compared to the wear liner.

  Here, in the cell structure, the cell 4 is formed by the structure 5 formed of the plate-like cemented carbide 3. In the present embodiment, the structure 5 is a cemented carbide member that defines the cell 4. The cross-sectional shape of the cell structure is a hexagonal shape in the illustrated example, but may be another polygonal shape such as a quadrangle or a triangle as will be described later. As shown in the figure, the cell 4 formed by the cell structure opens in the z-axis direction, that is, in a direction perpendicular to the surface 1 s of the wear-resistant liner 1. By adopting such a cell structure, it is possible to obtain the strength capable of resisting the impact of the charged material on the surface 1 s with the minimum cemented carbide 3. The structure 5 is integrally formed and has a uniform thickness. However, the structure 5 may be disassembled into a plurality of parts as necessary, and the thickness varies depending on the part. May be. For example, the structure 5 may be formed by combining a plurality of folded plate members formed of the cemented carbide 3 as in an example described later.

  On the other hand, in the surface layer portion of the wear-resistant liner 1, the base material 2 is filled into the cells 4 partitioned by the structure 5 of the cemented carbide 3. Since the base material 2 is softer than the cemented carbide 3, the base material 2 in the cell 4 is worn prior to contact with the charge. As a result, a concave portion is formed in the cell 4 surrounded by the structure 5 in the surface layer portion. However, since the cemented carbide 3 penetrates the surface layer portion and is embedded in the base material 2, the cemented carbide 3 will not be lost unless the concave portion formed in the cell 4 becomes too deep. For example, if the opening width of the cell 4 is less than the average particle size of the charge, the charge such as ore, lime and coke entering the cell 4 can be limited to those having a relatively small particle size. The wear of the base material 2 in 4 can be suppressed. A part of the charge having a relatively small particle size is deposited in the cell 4 to cover the surface of the base material 2. Such so-called cell flying effects can more effectively suppress the wear of the base material 2 and improve the durability of the wear-resistant liner 1.

  Here, the opening width of the cell 4 can be defined as the diameter of the inscribed circle in the cross section of the cell 4. In the example of FIG. 1 (the cross section of the cell 4 is hexagonal), the opening width of the cell 4 is equal to the distance between the opposite sides of the hexagonal cross section. Further, as in the example described later, if the cross section of the cell 4 is a quadrangle (substantially square), the opening width of the cell 4 is equal to the length of one side of the quadrangle of the cross section. If the cross section of the cell 4 is circular, the diameter of the cross section itself becomes the opening width.

(Variation of cell structure)
Next, with reference to FIG. 2, the variation of the cell structure formed with the cemented carbide 3 in the abrasion-resistant liner 1 is demonstrated. As described above, in the cell structure formed of the cemented carbide 3 with the wear-resistant liner 1 according to the present embodiment, the cross-sectional shape of the cell 4 is not limited to the hexagon as in the example shown in FIG. Alternatively, other shapes such as a square or a triangle may be used. In FIG. 2, (A) shows an example of a hexagon, (B) shows an example of a quadrangle, and (C) shows another example of a quadrangle. Although the example of the triangle is not illustrated, it can be realized in the same manner as the illustrated example. In addition to this, for example, various cell cross-sectional shapes generally known as those capable of realizing a honeycomb structure (in a broad sense, not limited to a hexagonal cell cross-section) It is possible to employ | adopt in other embodiment of this embodiment.

  Here, among the examples shown in FIGS. 2 (A) to (C), the amount of the cemented carbide 3 used is the smallest in the example shown in (A) (the cross-sectional shape of the cell 4 is hexagonal). is there. However, even in the examples shown in (B) and (C) (the cross-sectional shape of the cell 4 is square), the amount of the cemented carbide 3 used is significantly reduced compared to the conventional wear-resistant liner 91 shown in FIG. However, the durability of the equivalent abrasion resistant liner 1 can be obtained. That is, in the embodiment of the present invention, the cross-sectional shape of the cell 4 is, for example, a hexagon as shown in FIG. 2 (A), a rectangle as shown in (B) or (C), or It can be selected as appropriate depending on, for example, the formation process of the cell structure.

  As shown in FIG. 3, the cell structure may be formed by combining plate members 5 p formed of cemented carbide 3. FIG. 3A shows a cell 4 having a hexagonal cross section formed by combining plate members 5p. FIG. 3B shows a cell 4 having a quadrangular cross section that is also formed by combining plate members 5p. FIG. 3C shows a cell 4 having a triangular cross section formed by combining plate members 5p. In these examples, the plate member 5 p is a cemented carbide member that defines the cell 4.

  Alternatively, as shown in FIG. 4, in the cell structure, a casing 5 c formed of cemented carbide 3 and surrounding the cell 4 may be integrally formed. For example, FIG. 4A shows a hexagonal cylindrical casing 5c that forms a cell 4 having a hexagonal cross section, and FIG. 4B shows a rectangular cylindrical casing 5c that forms a cell 4 having a square cross section. FIG. 4C shows a triangular cylindrical casing 5c forming a cell 4 having a triangular cross section, and FIG. 4D shows a cylindrical casing 5c forming a cell 4 having a circular cross section. These casings 5c may be formed by joining plate members as shown in FIG. 3, for example. In these examples, the casing 5 c is a cemented carbide member that defines the cell 4.

  For example, the cell structures formed as shown in FIGS. 3 and 4 may be continuously arranged in contact with each other to form a honeycomb structure as in the example shown in FIG. Or a cell structure may be discretely arrange | positioned at intervals, like the example shown in FIG. 5A shows an example in which cells 4 having a hexagonal cross section are discretely arranged, FIG. 5B shows an example in which cells 4 having a quadrangular cross section are discretely arranged, and FIG. 5C shows a triangular cross section. An example in which the cells 4 are discretely arranged, and FIG. 5D shows an example in which the cells 4 having a circular cross section are discretely arranged. In the example of FIG. 5, the casing 5c integrally formed with respect to each cell 4 is shown as shown in FIG. 4, but a plate member 5p as shown in FIG. 3 may be combined. In addition, as for the space | interval of each cell structure, it is desirable to set it as less than the average particle diameter of a charge similarly to the opening width of the cell 4. FIG.

  With the arrangement of the cells 4 as in the example shown in FIG. 5 above, the cross-sectional shape of the cell structure is not limited to a plane-fillable polygon such as a hexagon, a quadrangle, and a triangle, A free shape such as a circular shape, an elliptical shape, or a semicircular shape as shown in FIG. 5D can be adopted. In any case, as described above, for example, if the opening width of the cell 4 and the interval between the cell structures are both less than the average particle diameter of the charge, the wear of the base material 2 is effectively suppressed. The durability of the wear resistant liner 1 can be improved.

  Alternatively, as in the example shown in FIG. 6, the cell structure may be formed by combining a plurality of folded plate members 5 f formed of the cemented carbide 3. In the example shown in FIG. 6A, the honeycomb structure in which the cells 4 having the hexagonal cross section as shown in FIG. 2A are arranged is formed by overlapping the folded plate members 5f while shifting in the width direction. Has been. In the example shown in FIG. 6B, a honeycomb structure in which the cells 4 having a square cross section as shown in FIG. 2B are arranged is formed by combining folded plate members 5f. In these examples, the folded plate member 5 f is a cemented carbide member that defines the cell 4.

(Through hole in cemented carbide)
Next, with reference to FIG. 7, the through-hole provided in the cemented carbide member which prescribes | regulates a cell is demonstrated. In FIG. 7, the through-hole 6 provided in the structure 5 formed of the cemented carbide 3 is shown by the front view and its III-III sectional view. In addition, since the through-hole 6 is an additional structure, it does not necessarily need to be provided. The through-hole 6 may be provided only in a part of the structure 5, for example, a portion located inside the wear-resistant liner 1, or provided in the entire structure 5 including the surface layer portion of the wear-resistant liner 1. May be. By providing the through hole 6, it is possible to further reduce the amount of the cemented carbide 3 used while ensuring the necessary strength. Further, by providing the through-hole 6, for example, when the base material 2 is cast into the cell 4, the molten base material 2 can pass through the structure 5 and move between the cells 4. It is easy to spread 2 over the entire cell structure. Further, when the structure 5 is engaged with the base material 2 at the through hole 6, the cemented carbide 3 forming the structure 5 is not easily dropped even if the base material 2 of the surface layer is worn. The plate member 5p shown in FIG. 3, the casing 5c shown in FIG. 4, and the folded plate member 5f shown in FIG.

(Example 1)
Next, Example 1 of the present invention will be described. In Example 1, the variation of the cell structure described above with reference to FIG. 2 demonstrates that the wear-resistant liner 1 has sufficient durability even if the cross-sectional shape of the cell 4 is different.

  In this example, Example 1A (abrasion resistant liner 1 employing the cell structure shown in FIG. 2A), Example 1B (abrasion resistant liner 1 employing the cell structure shown in FIG. 2B) , And a conventional example (conventional wear-resistant liner 91 shown in FIG. 10) was subjected to an experiment to compare the service life. In the experiment, each wear-resistant liner was placed on a swivel chute of a blast furnace, and the charge containing ore and coke was charged into the furnace for 5 to 7 million tons per year. The point of time at which the chute body was worn away due to breakage or the like was determined as the liner life. The operating temperature in the experiment was 100 ° C. to 700 ° C., and the average particle size of the charge was 10 mm. In Example 1A and Example 1B, the thickness of the cemented carbide member of the structure 5 was 2 mm. In Example 1A, the distance between opposite sides of the hexagon in the cross section of the cell 4 was 10 mm, and in Example 1B, the length of one side of the quadrilateral in the cross section of the cell 4 was 20 mm. In the conventional example, the diameter of the cemented carbide pin 93 was 25 mm. The results of the experiment are shown in Table 1.

  From the results of the experiment shown in Table 1, in Example 1A (the four cross-sectional shapes of the cells are hexagonal), the wear resistant liner 1 is used even though the amount of the cemented carbide 3 used is 1/17 that of the conventional example. It can be seen that the lifetime of is equal to that of the conventional example. Further, even in Example 1B (cell 4 has a square cross-sectional shape), the amount of cemented carbide 3 used is 1.5 times that of Example 1A, but the amount of cemented carbide 3 used is larger than that of the conventional example. Is much less (approximately 1/11) and has a similar lifetime. From this result, it can be said that in the embodiment of the present invention, it is proved that various cross-sectional shapes of the cells 4 can be selected according to the process of forming the cell structure.

(Example 2)
Subsequently, Example 2 of the present invention will be described. As shown in FIG. 8, in Example 2, the opening width d of the cell 4 of the cell structure in the wear-resistant liner 1 according to the above embodiment and the thickness t of the cemented carbide member constituting the structure 5 are shown. More preferred values were verified. Here, as the opening width b of the cell 4 is larger, the amount of the cemented carbide 3 used can be reduced. However, if the opening width b is too large, the cell having a relatively large particle size among the charges such as ore, lime, and coke is used. 4, the wear of the base material 2 proceeds. Further, the thinner the thickness t of the cemented carbide member, the more the amount of the cemented carbide 3 used can be reduced. However, when the thickness is too small, the bending stress applied due to the impact of the charged material on the surface 1s of the wear-resistant liner 1 is reduced. The cemented carbide alloy member buckles and cannot secure sufficient durability.

  In this example, first, an experiment was performed to compare the service life of Examples 2A to 2C, Comparative Example 2A, Comparative Example 2B, and the conventional example. In the experiment, in the same manner as in Example 1 described above, each wear-resistant liner was installed on a swirl chute of a blast furnace, and a charge containing ore and coke was charged into the furnace. The detailed conditions of the experiment are the same as in Example 1 and will not be described. In Example 2A to Example 2C, Comparative Example 2A, and Comparative Example 2B, the wear-resistant liner 1 that employs a cell structure in which cells 4 having a square cross section as shown in FIG. The opening width d and the thickness t of the cemented carbide member were changed. In the conventional example, the conventional wear-resistant liner 91 shown in FIG. 10 is used. In the conventional example, the diameter of the cemented carbide pin 93 was 25 mm. The results of the experiment are shown in Table 2.

  First, regarding the opening width d of the cell 4, in Example 2A (opening width d is 10 mm) and Example 2B (opening width d is 7.0 mm), the life is the same as that of the conventional example, but Comparative Example 2A (opening width) When d is 12 mm), the lifetime is half that of the conventional example. In Example 2A, Example 2B, and Comparative Example 2A, since the thickness t of the cemented carbide member is 1.0 mm in common, the decrease in durability in Comparative Example 2A is due to the opening width d of the cell 4. It is thought to be due to change. Since the average particle size of the charged material in the experiment was 10 mm, in Comparative Example 2A, even the charged material having a relatively large particle size entered the cell 4 to advance the wear of the base material 2. As a result, it is considered that the life of the wear-resistant liner 1 is shorter than before. From this result, it can be seen that in the wear-resistant liner 1, the opening width d of the cell 4 is preferably less than the average particle diameter of the charge that contacts the surface 1 s of the wear-resistant liner 1.

  Next, with regard to the thickness t of the cemented carbide member, the lifespan in Example 2A (thickness t is 1.0 mm) and Example 2C (thickness t is 1.5 mm) is the same as that of the conventional example. In Example 2B (thickness t is 0.8 mm), the lifetime is half that of the conventional example. In Example 2A, Example 2C, and Comparative Example 2B, since the opening width d of the cell 4 is 10 mm in common, the decrease in durability in Comparative Example 2B is due to the change in the thickness t of the cemented carbide member. It is thought to be a thing. Since the strength against buckling of the cemented carbide member is determined by the thickness t, it is understood that the thickness t of the cemented carbide member in the wear-resistant liner 1 is desirably 1 mm or more.

  In this example, for wear-resistant liner 1 employing a cell structure in which cells 4 having a square cross section are arranged, more preferable values of opening width d of cell 4 and thickness t of the cemented carbide member were verified. For example, as shown in FIG. 2A, the same can be said for the wear-resistant liner that employs a cell structure in which cells 4 such as a hexagonal cross section, a triangular cross section, and a circular cross section are arranged. For example, when the cell 4 has a hexagonal cross section, the opening width of the cell 4 (diameter of the inscribed circle in the cross section = distance between the opposite sides of the hexagon) d is the average grain size of the charge that contacts the surface 1s of the wear-resistant liner 1. It is desirable that the diameter is less than the diameter, and the thickness t of the cemented carbide member is desirably 1 mm or more.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above-described embodiment, the wear-resistant liner is installed on the turning chute of the blast furnace, but the embodiment of the present invention is not limited to such an example. The wear-resistant liner according to the embodiment of the present invention includes various processes such as chutes that require wear resistance in various manufacturing industries such as other processes in iron making, cement manufacturing, ore mining and refining, mining industry, construction industry, etc. Can be installed in the device.

DESCRIPTION OF SYMBOLS 1 Wear-resistant liner 2 Base material 3 Cemented carbide 4 Cell 5 Structure 6 Through-hole

Claims (5)

A wear-resistant liner in which cemented carbide is embedded in the surface layer of the base material,
The wear-resistant liner, wherein the cemented carbide forms a cell structure in which cells opened in a direction perpendicular to the surface of the wear-resistant liner are continuously or discretely arranged.   The wear-resistant liner according to claim 1, wherein a diameter of an inscribed circle in a cross section of the cell is less than an average particle diameter of a material that contacts a surface of the wear-resistant liner.   The wear-resistant liner according to claim 1 or 2, wherein a thickness of the cemented carbide member defining the cell is 1 mm or more.   The wear resistance according to any one of claims 1 to 3, wherein the cells have a hexagonal cross section, a square cross section, or a triangular cross section to form a continuously arranged honeycomb structure. liner. The wear resistant liner according to any one of claims 1 to 4, wherein a through hole is formed in the cemented carbide member defining the cell.

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