JP7698201B2 - Wear-resistant liner, wear-resistant liner structure, and manufacturing method thereof - Google Patents

Description

The present invention relates to a wear-resistant liner.

In various industries that handle powders and ores, wear can cause equipment to become damaged during transportation and storage, eventually causing the equipment to stop functioning. To prevent this, wear-resistant liners are placed in areas prone to wear, suppressing the progression of wear and protecting the equipment.

For example, the rotating chutes used to charge steel raw materials such as coke and iron ore into the blast furnaces of steel mills are subjected to extremely large shocks and wear due to the collisions and movement of the steel raw materials. For this reason, wear-resistant liners are installed to protect the chute surface.

Wear-resistant liners are often made of wear-resistant alloys (e.g., wear-resistant steel, high Cr steel, etc.). In recent years, wear-resistant liners that combine wear-resistant metals with wear-resistant reinforcement materials made of ceramics _{( Si3N4} , SiC, _Al2O3 , _etc. ) or cemented carbide, which have a high wear-resistant effect, have been proposed to enhance wear resistance.

For example, Patent Document 1 proposes a wear-resistant liner in which a wear-resistant reinforcement made of silicon nitride ceramic is cast and fixed with a high Cr alloy as a matrix so that the wear-resistant reinforcement is exposed on the surface.
Furthermore, Patent Document 2 proposes a cast composite material in which the wear-resistant material is a cemented carbide containing tungsten carbide as a main component, and the base material is high-chromium cast iron.
Furthermore, Patent Document 3 proposes a wear-resistant liner in which a ceramic wear-resistant reinforcement is formed into a truncated cone shape and cast into a wear-resistant alloy that serves as a matrix to prevent the ceramic wear-resistant reinforcement from falling off.

JP 2010-058155 A JP 2009-006347 A JP 2020-180343 A

When a wear-resistant reinforcement material such as ceramics or cemented carbide is cast into a wear-resistant alloy as in Patent Documents 1 to 3, it is manufactured by casting or HIP (Hot Isostatic Press). However, since the thermal expansion coefficients of the ceramics or cemented carbide and the matrix alloy are different, there is a problem that thermal stress occurs during cooling and cracks occur in the matrix alloy. When cracks occur, the impact resistance is extremely deteriorated, and not only does the liner itself break, but the wear resistance also deteriorates, making it unusable as a wear-resistant liner. Furthermore, when microcracks occur, they are difficult to detect even during inspection, so they are installed in equipment without being noticed, which not only shortens the life of the wear-resistant liner but may also cause equipment failure.

The present invention aims to provide a wear-resistant liner that is free of cracks and is made of a wear-resistant reinforcement material such as ceramics or cemented carbide, and a matrix alloy that contains a wear-resistant alloy, thereby preventing the occurrence of cracks in the wear-resistant liner.

In order to solve the above problems, the inventors have conducted extensive research and development, and have obtained the following findings. In the following description, the surface of the liner that requires abrasion resistance because powder and other materials collide and slide is referred to as the front surface, and the opposite surface is referred to as the back surface.

(a) We investigated the manufacturing process of a wear-resistant liner (hereinafter sometimes referred to as a "liner") in which a wear-resistant reinforcement (hereinafter sometimes referred to as a "reinforcement") made of ceramics, cemented carbide, etc. is placed in a matrix alloy (hereinafter sometimes referred to as a "matrix alloy") made of a metal containing a wear-resistant alloy, and found that whether the casting method or the hot pressing method including the HIP method is used, the shrinkage of the wear-resistant reinforcement such as ceramics or cemented carbide is small during the cooling process, while the shrinkage of the matrix alloy is large, and tensile residual stress is generated in the matrix alloy in the thickness direction of the liner (hereinafter sometimes simply referred to as the "thickness direction"), which is the cause of the occurrence of cracks.

It was therefore discovered that in order to reduce the tensile residual stress in the matrix alloy, it would be effective to form a multi-layer structure of two or more layers of matrix alloy across the length of the reinforcing material in the thickness direction of the liner. Since the surface layer that constitutes the surface of the liner needs to be wear-resistant, it is desirable to use a wear-resistant alloy as in the past, but by making the layers other than the surface layer out of an easily deformable alloy such as mild steel, it is possible to absorb thermal stress and reduce residual stress. For example, it is effective to form a multi-layer structure in which the surface layer is made of a wear-resistant alloy and at least one of the other layers is made of an alloy with high deformability such as mild steel.

(a) When the surface layer of the matrix is made of a wear-resistant alloy and the other layers are made of mild steel, this mild steel can be made into a steel plate. When forming a liner using the HIP method, the shrinkage rate after HIP treatment is smaller for mild steel than for powder metallurgy, so forming it from mild steel plate can reduce residual stress.

Furthermore, by pre-drilling holes in the steel plate for inserting the reinforcing material, not only is it easier to position the reinforcing material, but it is also possible to prevent the reinforcing material from moving during HIP processing. This prevents the reinforcing material from becoming misaligned or tilted during the manufacturing process. If the reinforcing material becomes misaligned or tilted, uneven spacing between the reinforcing material on the liner surface will occur, and the parts with wider spacing will wear preferentially, which may shorten the life of the wear-resistant liner itself. Therefore, preventing the wear-resistant reinforcing material from becoming misaligned or tilted will contribute to extending the life of the liner.

(c) By making the layer on the backside mild steel, it is also possible to join abrasion-resistant liners together. Abrasion-resistant alloys (such as high Cr alloys and high-speed steel) on the surface of the liner are difficult to weld, but mild steel can be easily welded and joined. The inventors have also conducted extensive research and development into welding methods, and have found that liners can be welded together without thermal shock to the reinforcing material if a welding method with high input energy density and localized heat input, such as electron beam welding or laser welding, is used. Since liners can be welded together, even if a large liner is required, it can be manufactured by dividing it into several pieces and welding the backside of each liner to produce a large liner.

(d) By forming the liner into blocks of an easy-to-manufacture size and combining and welding the blocks according to the shape of the part to which the liner is to be attached, a liner assembly suitable for large or irregularly shaped equipment can be formed (hereinafter, the wear-resistant liner is considered as a block, and the liner formed by combining these blocks is referred to as the "liner assembly"). By forming the liner into blocks, it is possible to miniaturize manufacturing equipment such as HIP equipment. Also, by standardizing the block shape, it is possible to dramatically improve liner productivity. Furthermore, inspection equipment can also be miniaturized, and existing inspection equipment can be used, which is advantageous in terms of quality control.

The present invention has been made based on the above findings, and the gist of the present invention is as follows.
[1]
1. A wear liner having a wear resistant reinforcement disposed in a matrix alloy, comprising:
the matrix alloy has two or more layers across the entire length of the wear reinforcement in the thickness direction of the wear liner;
A wear-resistant liner, characterized in that among said plurality of layers, the layer closest to the surface of said wear-resistant liner is an alloy having wear resistance, and at least one of the other layers is mild steel.
[2]
The wear-resistant liner according to claim 1, wherein the layer closest to the rear surface of the wear-resistant liner among the plurality of layers is mild steel.
[3]
The wear-resistant liner according to claim 1 or 2, wherein the matrix alloy has a layer of an alloy having wear resistance on the surface side of the wear-resistant liner relative to the wear-resistant reinforcement in the thickness direction of the wear-resistant liner.
[4]
The wear-resistant liner according to any one of [1] to [3], wherein the wear-resistant reinforcement is at least one of ceramics and cemented carbide.
[5]
The wear-resistant liner according to any one of [1] to [4], wherein the wear-resistant alloy is at least one of a high Cr alloy and a high-speed steel.
[6]
A wear-resistant liner described in any one of [1] to [5], wherein the matrix alloy has one or more layers on the back side of the wear-resistant liner relative to the wear-resistant reinforcement in the thickness direction of the wear-resistant liner.
[7]
The wear-resistant liner according to claim 6, wherein the layer among the plurality of layers closest to the rear surface of the wear-resistant liner and the layer closest to the rear surface of the wear-resistant liner relative to the wear-resistant reinforcement are integral with each other.
[8]
A wear-resistant liner structure comprising a plurality of wear-resistant liners according to any one of the above [1] to [7].
[9]
The wear-resistant liner structure according to claim 8, wherein adjacent wear-resistant liners are joined together at their back surfaces.
[10]
The wear-resistant liner structure according to claim 8 or 9, wherein the joint is electron beam welding or laser welding.
[11]
The wear-resistant liner structure according to any one of claims [8] to [10], wherein the bonding is performed only at the layer constituting the back surface of the wear-resistant liner.
[12]
A method for manufacturing the wear-resistant liner according to any one of the above [1] to [7],
Providing powder materials of a wear-resistant reinforcement and two or more alloys including at least a wear-resistant alloy and mild steel;
disposing the powder material around the wear-resistant reinforcement in such a way that the layer closest to the surface of the wear-resistant liner is the wear-resistant alloy over the entire length of the wear-resistant reinforcement in the thickness direction of the wear-resistant liner;
A method of manufacturing a wear liner comprising the step of HIPing the powder material disposed around the wear reinforcement.
[13]
Further, a step of preparing a steel plate having an opening at a portion corresponding to a predetermined position where the wear-resistant reinforcement material is to be disposed;
A method for manufacturing a wear liner as described in [12], comprising a step of disposing the wear-resistant reinforcement in the opening of the steel plate.
[14]
Further, a step of preparing a steel plate having a recess in a portion corresponding to a predetermined position where the wear-resistant reinforcement is to be disposed;
A method for manufacturing a wear liner as described in [12], comprising a step of arranging the wear-resistant reinforcement in a recess of the steel plate.
[15]
A method for manufacturing the wear-resistant liner assembly according to any one of the above [8] to [11], comprising the steps of arranging a plurality of the wear-resistant liners adjacent to each other;
A method for manufacturing a wear liner assembly, comprising the step of bonding adjacent wear liners at their backsides.
[16]
The method for manufacturing a wear-resistant liner assembly according to claim 15, wherein the joining is performed by electron beam welding or laser welding.

According to the present invention, it is possible to obtain a wear-resistant liner that is composed of a wear-resistant reinforcement material made of ceramics, cemented carbide, etc. and a matrix alloy made of a wear-resistant alloy, etc., in which cracks in the matrix alloy during the manufacturing process are suppressed, which leads to a longer life of the wear-resistant liner.
Furthermore, the present invention allows the wear liner to be divided into small blocks, which contributes to improving the productivity and quality of the wear liner. Furthermore, it is possible to manufacture a large wear liner by combining small blocks.

1 is a conceptual diagram showing an example of a wear liner according to the present invention. FIG. 2 is a conceptual diagram showing a cross section of the wear liner of FIG. 1. FIG. 4 is a conceptual diagram showing a cross section of another example of a wear liner according to the present invention. FIG. 4 is a conceptual diagram showing a cross section of yet another example of a wear-resistant liner according to the present invention. FIG. 1 is a conceptual diagram showing an example of a conventional wear liner. FIG. 1 is a conceptual diagram showing an example of an anti-wear liner that serves as a standard block for an abrasion liner structure according to the present invention. 1 is a conceptual diagram showing an example of a wear liner structure according to the present invention. FIG. 2 is a diagram showing the back side of an example of a wear liner structure according to the present invention.

One embodiment of the present invention will be described with reference to the drawings.

[Wear-resistant liner]
FIG. 1 is a diagram showing an outline of an embodiment of the wear-resistant liner according to the present invention. The wear-resistant liner 1 according to this embodiment has a configuration in which the wear-resistant reinforcement 3 is embedded in the matrix alloy 2. The wear-resistant liner 1 is usually in a plate shape, and one of the surfaces is a surface on which powder such as raw steel materials and ores collide and slide in contact with each other. This surface is referred to as the front surface in this specification. The opposite surface facing the front surface is referred to as the back surface in this specification. The direction perpendicular to the front surface is the thickness direction. Therefore, the wear resistance is usually imparted to the surface of the wear-resistant liner, thereby extending the life of the liner. FIG. 1 shows a case in which the matrix alloy 2 has three layers (2a, 2b, 2c) over the entire length of the wear-resistant reinforcement 3 in the thickness direction (sometimes simply referred to as the "thickness direction") of the wear-resistant liner 1.

Figure 2 is a schematic diagram showing a cross section of the wear liner of Figure 1 cut along the line AA. As can be seen from the cross section of the wear liner, the reinforcement 3 is arranged in the thickness direction of the liner and is arranged in the matrix alloy 2. Here, the total length 21 of the wear resistant reinforcement refers to the length from the surface of the reinforcement 3 (the surface on the surface side of the wear liner) to the back surface of the reinforcement 3 (the surface on the back side of the wear liner) in the thickness direction of the wear liner. In the example of Figure 2, since the thickness of the liner and the length of the reinforcement are the same, the surface of the reinforcement constitutes a part of the surface of the liner, and the back surface of the reinforcement constitutes a part of the back surface of the liner. In the example of Figure 2, the matrix alloy has three layers (2a, 2b, 2c) over the entire length of the reinforcement in the thickness direction of the liner.

Figure 3 is a conceptual diagram showing a liner cross section in another embodiment. In the example of Figure 3, the reinforcement 3 is completely embedded in the matrix alloy 2, and the reinforcement 3 cannot be seen from the front or back of the liner. The matrix alloy 2 of the liner has four layers, 2a, 2b, 2c, and 2d, in that order from the front. The layer on the front side of the matrix alloy 2 (the top layer in the figure) 2a is arranged to wrap the reinforcement 3, and is in contact with the front side of the reinforcement 3 and also in contact with the reinforcement 3 in the longitudinal direction. On the other hand, the layer on the back side of the matrix alloy 2 (the bottom layer in the figure) 2d is in contact with the back side of the reinforcement 3, but is not in contact with the reinforcement 3 in the longitudinal direction. In the example of Figure 3, the matrix alloy 2 has three layers (2a, 2b, 2c) over the entire length of the reinforcement 3 in the liner thickness direction.

In this way, as long as the matrix alloy has two or more layers arranged over the entire length of the reinforcement, it does not matter what kind of layers and how many there are on the front side or back side of the liner from the reinforcement. However, it remains desirable that the layer of the matrix alloy on the front side of the liner from the reinforcement be an alloy that has wear resistance. There are no restrictions on the type or number of layers of the matrix alloy on the back side of the liner from the reinforcement, but it is preferable that it be a layer of mild steel because of its ease of handling and good joining properties.

In the examples of Figures 1 to 3, the layer on the surface side of the liner (the top layer in the figures) 2a constitutes the liner surface, so it is preferable that it is an alloy with wear resistance. In the case of Figure 3, the entire liner surface is made of an alloy with wear resistance, but as wear progresses, the surface of the reinforcing material becomes exposed, and it eventually takes on the same form as Figure 2.

Figure 5 shows an overview of the structure of a conventional wear-resistant liner (for example, the liner in Patent Documents 1 and 2). As shown in Figure 5, conventional liners have one layer, i.e., one type of matrix alloy 2, arranged over the entire length of the reinforcing material 3, which is an alloy with wear resistance. Since the thermal expansion coefficients of the reinforcing material 3, such as ceramics or cemented carbide, and the matrix alloy 2, which is a metal, are significantly different, during the manufacturing process of the liner, the thermal contraction of the metal is large, and tensile residual stress is generated in the matrix alloy. This tensile residual stress is the cause of the generation of cracks in the matrix alloy.

Therefore, the matrix alloy is made into a multi-layer structure so that the thermal contraction difference between the matrix alloy and the reinforcing material such as ceramics or cemented carbide during liner manufacturing can be absorbed. Therefore, it is desirable that the outermost layer of the matrix alloy is an alloy with wear resistance, while the other layers are alloys with high deformability and can absorb the thermal contraction difference. High deformability means that the alloy deforms without breaking even when stress is applied. For example, an alloy with a large fracture strain such as mild steel is preferable. Although light metals such as aluminum also have high deformability, they have a low melting point and are difficult to combine with, for example, wear-resistant steel. Therefore, it is preferable to use mild steel for general purposes. Here, mild steel generally refers to steel with a tensile strength of 490 MPa or less and a carbon (C) content of 0.30 mass% or less. Mild steel has a large fracture strain and high deformability. For this reason, by inserting a layer of mild steel into the matrix alloy arranged along the entire length of the reinforcing material, the thermal contraction difference can be absorbed during the liner manufacturing process and the tensile residual stress in the matrix alloy can be reduced.

On the other hand, for example, in a case where a layer of mild steel is added to the back side of a liner composed of a single layer of abrasion-resistant alloy as shown in Figure 5, the matrix alloy placed over the entire length of the reinforcement is only an alloy having abrasion resistance, so even if a layer of mild steel is added to the back side, it is not possible to absorb the difference in thermal contraction between the reinforcement and the matrix alloy. Therefore, it is important that the matrix alloy has two or more layers over the entire length of the reinforcement, and it is preferable that one of these layers is mild steel.

More preferably, the mild steel layer is the layer closest to the back surface of the wear-resistant liner among the multiple layers of the matrix alloy. When one side of the reinforcing material is mild steel, it is easier to absorb the difference in thermal contraction, and as described below, it provides excellent handling and joining properties.

As explained in the example of FIG. 3, the matrix alloy may have a layer on the back side of the liner from the reinforcement, and it is particularly preferable that the layer be made of mild steel. Therefore, the layer on the back side of the matrix alloy arranged over the entire length of the reinforcement (e.g., 2c in FIG. 3) and the layer on the back side of the liner from the reinforcement (e.g., 2d in FIG. 3) may both be made of mild steel. Of course, these layers (e.g., 2c and 2d in FIG. 3) may be made of mild steel of the same material, or may be integrated. FIG. 4 is a diagram showing the concept when the layer on the back side of the matrix alloy arranged over the entire length of the reinforcement and the layer arranged on the back side of the reinforcement are the same. If this layer (the layer on the back side) is mild steel, it is preferable because it is easier to absorb the thermal contraction difference and also improves handling and joining properties.

There is no particular limit to the type of matrix alloy. There is no particular limit to which alloy is applied to which layer. It may be selected based on the liner structure, the target powder or ore, etc. The matrix alloy placed on the outermost surface of the liner is preferably an alloy with wear resistance, but the material is not particularly limited. Examples of alloys with wear resistance include high Cr cast iron containing 12-30 wt% Cr and 1-3 wt% C with added Si, Mn, Ni, Cu, Mo, W, etc., and high speed steel (high speed tool steel, various alloys of JIS standard SKH). One of these may be selected, or a combination of them may be used.

As the reinforcing material, ceramics, cemented carbide, etc. can be used. The type of ceramic is not particularly limited, and may be, for example, Si ₃ N ₄ , sialon, SiC, ZrO ₂ , Al ₂ O ₃ , etc. The cemented carbide is also not particularly limited, and may be, for example, not only WC-Co, but also a composite carbide obtained by adding TiC, TaC, etc. to WC, or a composite carbide obtained by replacing Co with Ni, Ni-Cr, Ni-Mo, etc. In other words, at least one of ceramics and cemented carbide is sufficient, and both may be used.
The shape of the wear-resistant reinforcement is not particularly limited. The reinforcement shown in Figs. 1 to 4 is a square prism, but is not limited thereto. For example, it may be cylindrical or truncated cone. There are also shapes shown in Patent Documents 1 and 3. From the viewpoint of wear resistance, it is preferable that the area of the reinforcement surface (the surface constituting the liner surface) on the liner surface side is large. However, if the area of the reinforcement surface is large, the area of the matrix alloy is accordingly small. If there is no adequate matrix alloy between the reinforcements, the reinforcements will collide with each other, causing damage to the reinforcement and increasing the cost of the reinforcement. The size of the reinforcement may be appropriately determined based on the size and hardness of the powder or ore to be targeted.

[Wear-resistant liner structure]
Wear-resistant liners are used to protect equipment, and their size and shape are determined according to each piece of equipment. Usually, they are manufactured as a single unit according to each piece of equipment. However, in order to manufacture large liners or liners with complex shapes as a single unit, not only do large manufacturing equipment (e.g., HIP equipment) and the like are required, but also the size of inspection equipment for defects such as cracks becomes larger, which not only reduces productivity but also makes the manufacturing equipment expensive. Therefore, these problems can be solved by combining small wear-resistant liners into blocks.

The inventors have discovered that by combining multiple abrasion-resistant liners as described above into blocks, it is possible to efficiently manufacture abrasion-resistant liners suitable for large-scale equipment or irregular-shaped equipment. The abrasion-resistant liner assembly suitable for large-scale equipment or irregular-shaped equipment, which is composed of multiple abrasion-resistant liners (blocks), is called an abrasion-resistant liner assembly.

For example, multiple wear-resistant liners are manufactured based on a standard type of wear-resistant liner that can be manufactured using existing HIP equipment, and these standard wear-resistant liners (blocks) are lined up and joined to fit the shape of the equipment to which the liners will be attached, making it possible to manufacture large wear-resistant liners (wear-resistant liner structures).

Figure 6 shows an example of an abrasion-resistant liner with two layers of matrix alloy. This can be thought of as the middle layer 2b of the matrix alloy layers shown in Figure 4 becoming the surface layer 2a. Therefore, the surface layer 2a of the matrix alloy in Figure 6 is an alloy with abrasion resistance, and the layer 2c on the back side is a layer of mild steel. An example of this abrasion-resistant liner as a standard abrasion-resistant liner (block) will be explained below.

Figure 7 shows an example of an abrasion-resistant liner assembly made by combining five standard abrasion-resistant liners (blocks) as shown in Figure 6. By combining blocks in this way, abrasion-resistant liner assemblies of various shapes can be manufactured. By joining adjacent blocks together, an integrated abrasion-resistant liner assembly can be obtained. It is recommended that the blocks be joined on the back surface. If they are joined on the front surface of the liner, they will be exposed to an abrasive environment, and the joints will wear and fall apart. When joining the back surface of the liner, joining is easier if the matrix alloy on the back surface is mild steel. For example, when welding mild steel, existing welding methods can be applied, and it is easier to weld than abrasion-resistant steel.

The joining method is not particularly limited. It may be the welding described above or mechanical joining. The back side is not exposed to an abrasive environment, so even if an existing joining method is applied, the joint will not deteriorate. Even in the case of welding, the welding method is not particularly limited. Existing welding methods such as arc welding and laser welding can be applied. In the case of welding, depending on the amount of heat input, wear-resistant reinforcement materials such as ceramics and cemented carbide may be affected, so if possible, a welding method with high heat density and which allows the amount of heat to be appropriately controlled, such as laser welding or electron beam welding, is preferable.

In addition, with laser welding or electron beam welding, the heat-affected zone is limited, so the joining can be done without affecting the wear-resistant reinforcement materials such as ceramics and cemented carbide. Furthermore, with laser welding or electron beam welding, the shape of the back surface can be left as is when welding, making it easier to attach the integrated wear-resistant liner structure to the equipment.

Figure 8 shows an example of a standard liner that has been laser welded. Figure 8 shows the back side of the liner, with six square blocks lined up in the foreground, and their boundaries laser welded. In addition, the laser welding is done only within the layer of the matrix alloy that constitutes the back side of the liner (the mild steel layer in the case of Figure 8). By joining only the mild steel layer, a highly reliable joint is obtained. Because the back side of the liner is not exposed to an abrasive environment, sufficient strength is obtained by welding only the mild steel layer, and there is no risk of the blocks coming off during use.

[Manufacturing method]
An embodiment of a method for manufacturing an abrasion-resistant liner will be described. The manufacturing method is not limited as long as it satisfies the requirements of the abrasion-resistant liner and the requirements of the abrasion-resistant liner structure defined in the present invention. The method described here is one example of the manufacturing method. The abrasion-resistant liner can be manufactured by a powder metallurgy method, specifically, a hot press or HIP (Hot Isostatic Press) method. Hereinafter, an example will be described in which the abrasion-resistant liner shown in FIG. 3 is manufactured by the HIP method.

Prepare powder of the alloy that will become the matrix alloy. For example, if the first layer (2a in FIG. 3) from the liner surface is a high Cr alloy, the second layer (2b) is an alloy of a high Cr alloy and mild steel, the third layer (2c) is mild steel, and the fourth layer (2d) is mild steel with a lower carbon content than the third layer, prepare powder of each alloy. There are no particular limitations on the method of powder preparation or the properties of the powder. The alloy powder can be prepared by applying a well-known alloy powdering technique. Meanwhile, prepare a reinforcing material. As mentioned above, there are no particular limitations on the material or shape of the reinforcing material. It can be manufactured according to the desired specifications.

To perform HIP, the alloy powder that will become the fourth layer is poured into the capsule and spread out in layers. Next, the wear-resistant reinforcement is placed in the designated position. Next, alloy powder for the third layer, alloy powder for the second layer, and alloy powder for the first layer are poured in in that order in layers, so that the reinforcement does not shift out of position. After the alloy powder is poured in, the capsule is sealed and the pressure inside the capsule is reduced. The reduced pressure creates a vacuum inside the capsule.

The capsule is then loaded into a HIP device and subjected to HIP processing. The conditions for the HIP processing may be appropriately selected according to the well-known HIP method. For example, heating (e.g., 1200°C to 1400°C) and pressure (e.g., 250 MPa to 600 MPa) may be performed. This sinters the powder material by HIP processing. After the HIP processing is completed, the capsule is removed from the HIP device, and the liner is molded to obtain a wear-resistant liner of the desired shape. Note that when the capsule is heated and pressurized to manufacture the liner, the liner will shrink, but this is natural in the HIP method and can be predicted in advance. Therefore, the capsule and the amount of alloy powder can be determined taking the shrinkage into account. This can also be done by applying the well-known HIP method.

Instead of the alloy powder, a plate of the alloy may be used. For example, a mild steel plate may be used instead of the mild steel of the third layer in the above example. In this case, the mild steel plate is pre-opened at the location where the reinforcing material will be placed. After the alloy powder of the fourth layer (corresponding to the bottom) is poured in a layer, the mild steel plate that will become the third layer is placed on top of the fourth layer, the reinforcing material is placed in the steel plate openings, and the alloy powder of the second layer and the alloy powder of the first layer are poured in order. By making the third layer a mild steel plate with openings, not only is it easier to position the reinforcing material, but it is also possible to prevent the reinforcing material from shifting or tilting during the HIP process. Since the steel plate shrinks less during the HIP process than the alloy powder, the shape of the steel plate can be determined by predicting this shrinkage in advance.

In addition, when the third and fourth layers in the above example are made of the same mild steel, they can be treated as one layer and a steel plate can be applied to it. That is, the configuration is as shown in FIG. 4. When the third layer (2c in FIG. 4) in FIG. 4 is made of steel plate, a recess is formed in the mild steel plate in advance at the location where the reinforcing material is to be placed. Then, the mild steel plate with this recess is placed in the capsule, and the reinforcing material is inserted and placed in the recess. This prevents the reinforcing material from shifting or tilting during the HIP process, as in the above example. Since the steel plate shrinks less during the HIP process than the alloy powder, the shape of the steel plate can be determined by predicting this shrinkage in advance. In addition, the mild steel plate that will become the third layer (bottom layer) can be used as part of the capsule used in the HIP process.

Above, an example of the manufacturing method of the wear-resistant liner according to the present invention has been described. The manufacturing method of the wear-resistant liner assembly will be described using the wear-resistant liner manufactured in this way as one block. For example, the liner shown in FIG. 6 is used as a standard block, and a plurality of such blocks are combined to manufacture the wear-resistant liner assembly. For example, as shown in FIG. 7, the wear-resistant liners are arranged adjacent to each other on a flat surface to form a liner assembly of the desired size. At this time, it is recommended to turn each wear-resistant liner upside down and arrange them so that the back surface is visible. Next, adjacent liners are joined together. There is no particular limitation on the joining method, but laser welding or electron beam welding has a high input energy density, so that heat load is not applied over a wide area and there is no effect on wear-resistant reinforcement materials such as ceramics and cemented carbide. Another advantage of laser welding or electron beam welding is that the weld bead is small, so there is little effect on the back surface shape. For laser welding or electron beam welding of the back surface, only the layer of mild steel that constitutes the back surface side needs to be welded. Welding is easy within the range of the mild steel layer, and defects do not occur at the boundary of the alloy layer. In addition, the back surface of the liner is not exposed to an abrasive environment, so the welds do not wear out, allowing the liner structure to be maintained for a long time.

In addition, by making the liner into a standard block, existing HIP equipment and defect detection equipment can be used. Furthermore, by making the liner (block) smaller, not only is the quality of the HIP process improved, but shrinkage is also kept to a minimum, which improves shape precision. Furthermore, the defect inspection accuracy can be improved, and the accuracy of detecting microcracks can also be increased. For all of the above, there are great advantages in terms of quality control, and productivity can also be significantly improved. By combining liners that become standard blocks, it becomes possible to apply the wear-resistant liner of the present invention to any type of equipment.

As the wear-resistant liner according to the present invention, a liner was prepared in which the matrix alloy is composed of high Cr cast iron in the first layer from the surface layer of the liner and mild steel in the second layer. In other words, it corresponds to the combination of the second layer (2b in FIG. 4) and the third layer (2c) in FIG. 4. The test materials were one in which the matrix alloy was prepared entirely from alloy powder (test material 1), one in which mild steel plate with an opening was used (test material 2), one in which mild steel plate with a recess was used (test material 3), and, as a comparative example, one in which the matrix alloy was only high Cr cast iron (comparison), seven of each were manufactured by the HIP method. The reinforcing materials and liner shapes are as shown below.

Ceramic wear-resistant reinforcement: _{Si3N4 W22mm} x D22mm x H37mm
Wear-resistant liner dimensions: W74mm x D74mm x H45mm
Arrangement of reinforcement in wear-resistant liner: 3 pieces x 3 pieces = 9 pieces arranged as seen from the liner surface

After the manufacturing, the appearance was inspected and the presence or absence of cracks in the matrix alloy was confirmed by a fluorescent flaw detection method. The results are shown in Table 1.

Next, a plurality of each of the test materials 1 to 3 manufactured above were lined up horizontally, and adjacent liners were welded together with an electron beam to manufacture an abrasion-resistant liner assembly. Figure 8 shows an example of the manufactured liner assembly. The six square pieces lined up in a row on the front side of Figure 8 are the liners. The rectangular part and rod-shaped protrusions on the back side of Figure 8 are jigs for fixing the liner to the target equipment and are not related to the present invention. The electron beam welding only reached the mild steel layer of the liner and did not reach the high Cr cast iron layer on the surface side. Furthermore, as a comparative example, a liner of the same size (a liner of the same size as the six test materials 1 to 3 lined up in a row) was manufactured by the HIP method as in the conventional case, with the matrix alloy being only high Cr cast iron. In the manufacture of the conventional product as the comparative example, cracks occurred in the matrix alloy, which reduced the product yield. In the end, although five liners were manufactured as the comparative example, only two were crack-free.

Next, they were installed in an actual steelmaking blast furnace and a comparative test of wear resistance was conducted. Liner assemblies made of each of test materials 1 to 3 and a conventional integrally molded liner as a comparative example were installed on the inner surface of a rotating chute, which is a facility for charging raw steel materials into a blast furnace, and the actual facility was operated to check the wear status. After about six months of continuous operation, the liners were removed and the wear status was visually checked. As a result, the liner assemblies made of test materials 1 to 3 and the conventional integral liner had almost the same wear status. This is because the liner structure is the same, with ceramic wear-resistant reinforcement placed in high Cr cast iron. However, upon closer observation, the liner assemblies of test material 1 and the conventional integral liner were selectively worn in the areas where the reinforcement was misaligned and the reinforcement spacing was wider. The liner structures made from test materials 2 and 3 had evenly-spaced reinforcing materials, and selective wear of the high-Cr cast iron that formed the joints did not occur.

The present invention can be used in any industry that uses powders, ores, etc.

Reference Signs List 1: Wear-resistant liner 2: Matrix alloy 2a, 2b, 2c, 2d: Each layer of matrix alloy 3: Wear-resistant reinforcement 11: Wear-resistant liner structure 21: Total length of wear-resistant reinforcement

Claims (16)

1. A wear liner having a wear resistant reinforcement disposed in a matrix alloy, comprising:
the matrix alloy has two or more layers across the entire length of the wear reinforcement in the thickness direction of the wear liner;
A wear-resistant liner, characterized in that among said plurality of layers, the layer closest to the surface of said wear-resistant liner is an alloy having wear resistance, and at least one of the other layers is mild steel. The wear liner according to claim 1, wherein the layer of the plurality of layers closest to the back surface of the wear liner is mild steel. The wear-resistant liner according to claim 1 or 2, wherein the matrix alloy has a layer of a wear-resistant alloy on the surface side of the wear-resistant liner relative to the wear-resistant reinforcement in the thickness direction of the wear-resistant liner. The wear-resistant liner according to any one of claims 1 to 3, wherein the wear-resistant reinforcement is at least one of ceramics and cemented carbide. The wear-resistant liner according to any one of claims 1 to 4, wherein the wear-resistant alloy is at least one of a high Cr alloy and a high-speed steel. The wear-resistant liner according to any one of claims 1 to 5, wherein the matrix alloy has one or more layers on the back side of the wear-resistant liner from the wear-resistant reinforcement in the thickness direction of the wear-resistant liner. The wear liner according to claim 6, wherein the layer closest to the rear surface of the wear liner among the plurality of layers and the layer closest to the rear surface of the wear liner from the wear reinforcement are integral. A wear-resistant liner structure characterized by being composed of a plurality of wear-resistant liners according to any one of claims 1 to 7. The wear-resistant liner structure according to claim 8, wherein adjacent wear-resistant liners are joined together on their back surfaces. The wear liner construction of claim 9 , wherein the bond is an electron beam weld or a laser weld. The wear liner structure according to claim 9 or 10 , wherein the bonding is performed only at a layer constituting a back surface of the wear liner. A method for manufacturing the wear liner according to any one of claims 1 to 7, comprising the steps of:
Providing powder materials of a wear-resistant reinforcement and two or more alloys including at least a wear-resistant alloy and mild steel;
disposing the powder material around the wear-resistant reinforcement in such a way that the layer closest to the surface of the wear-resistant liner is the wear-resistant alloy over the entire length of the wear-resistant reinforcement in the thickness direction of the wear-resistant liner;
A method for manufacturing a wear liner comprising the step of HIPing the powder material disposed around the wear reinforcement. Further, a step of preparing a steel plate having an opening at a portion corresponding to a predetermined position where the wear-resistant reinforcement material is to be disposed;
The method of claim 12 including the step of placing the wear reinforcement in an opening in the steel plate. Further, a step of preparing a steel plate having a recess in a portion corresponding to a predetermined position where the wear-resistant reinforcement is to be disposed;
The method of claim 12 including the step of disposing the wear reinforcement in a recess in the steel plate. A method for manufacturing the wear liner structure according to any one of claims 8 to 11, comprising the steps of arranging a plurality of the wear liners adjacent to each other;
A method for manufacturing a wear liner assembly, comprising the step of bonding adjacent wear liners at their backsides. The method for manufacturing a wear-resistant liner structure according to claim 15, wherein the joining is performed by electron beam welding or laser welding.

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