Wear-resistant liner, wear-resistant liner structure, and method for manufacturing them

Abstract

To suppress occurrence of breakages (cracks) in an abrasion resistant liner during a manufacturing step in an abrasion resistant liner composed of an abrasion resistant reinforcing material made of ceramics and superalloys and the like, and a matrix alloy made of abrasion resistant alloys and the like.SOLUTION: According to the present invention, a matrix alloy has a plurality of layers of two or more layers in a thickness direction of the abrasion resistant liner over an entire length of the abrasion resistant reinforcing material, a layer closest to a surface of the abrasion resistant liner among the plurality of layers is an alloy having abrasion resistance, and at least one of the other layers is mild steel. Additionally, multiple wear resistant liners can be aligned and joined (preferably electron beam welded or laser welded) on backsides to form an abrasion resistant liner construct that can be manufactured with high productivity and high quality yield.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wear-resistant liner.

Background Art

[0002] In various industries that handle powders and ores, during the transportation and storage of powders and ores, equipment damage progresses due to wear, and as a result, the equipment may stop functioning. To prevent this, wear-resistant liners are placed in parts where wear is likely to occur to suppress the progress of wear and protect the equipment.

[0003] For example, the swivel chute for charging steel raw materials such as coke and iron ore into the blast furnace of a steelworks is subjected to very large impacts due to the collision and movement of the steel raw materials and wears. Therefore, a wear-resistant liner for protecting the chute surface is attached.

[0004] Wear-resistant liners are often made of wear-resistant alloys (such as wear-resistant steel, high-Cr steel, etc.). In recent years, in order to enhance wear resistance, wear-resistant liners that combine wear-resistant reinforcements made of ceramics (such as Si3N4, SiC, Al2O3, etc.) or cemented carbides with large wear-resistant effects and wear-resistant metals have been proposed.

[0005] For example, Patent Document 1 proposes a wear-resistant liner in which a wear-resistant reinforcement made of silicon nitride ceramics is cast and fixed with a high-Cr alloy as the matrix so as to be exposed on the surface. Further, Patent Document 2 proposes a cast composite material in which the wear-resistant material is a cemented carbide mainly composed of tungsten carbide and the material of 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 in a frustum of a cone shape and cast and embedded in a wear-resistant alloy as the matrix to prevent the ceramic wear-resistant reinforcement from falling off.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-058155 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-006347 [Patent Document 3] Japanese Patent Application Laid-Open No. 2020-180343 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] When fixing wear-resistant reinforcing materials such as ceramics and cemented carbide in a wear-resistant alloy by casting as in Patent Documents 1 to 3, they are manufactured by casting or HIP (Hot Isostatic Press) method. However, since the thermal expansion coefficients of ceramics, cemented carbide, etc. and the alloy serving as the matrix are different, thermal stress is generated during cooling, and there is a problem that cracks occur in the matrix alloy. When such cracks occur, the impact resistance deteriorates extremely, not only the liner itself is damaged, but also the wear resistance deteriorates, so it cannot be used as a wear-resistant liner. Furthermore, when microcracks occur, they are difficult to detect even by inspection, so they may be installed in equipment without knowing it, resulting in not only a short life of the wear-resistant liner but also a cause of equipment failure in some cases.

[0008] Therefore, an object of the present invention is to suppress the occurrence of cracks in a wear-resistant liner composed of a wear-resistant reinforcing material such as ceramics or cemented carbide and a matrix alloy containing a wear-resistant alloy, and to provide a wear-resistant liner without cracks. [Means for Solving the Problems]

[0009] In order to solve the above problems, the present inventors have conducted intensive research and development and obtained the following findings. Hereinafter, the surface of the liner that requires wear resistance due to the collision and sliding of powders, etc. is defined as the front surface, and the opposite surface is defined as the back surface.

[0010] (A) When verifying the manufacturing process of a wear-resistant liner (hereinafter sometimes referred to as "liner") in which a wear-resistant reinforcing material made of ceramics, cemented carbide, etc. (hereinafter sometimes referred to as "reinforcing material") is arranged in a matrix alloy made of a metal including a wear-resistant alloy (hereinafter sometimes referred to as "matrix alloy"), it was found that whether by casting or by a hot pressing method including the HIP method, during the cooling process, the shrinkage of the wear-resistant reinforcing material such as ceramics and cemented carbide is small, 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 "thickness direction"), which is the cause of crack generation.

[0011] Therefore, in order to reduce the tensile residual stress in the matrix alloy, it was found that in the thickness direction of the liner, the matrix alloy should be made into a multi-layer structure of two or more layers over the length of the reinforcing material. Since the surface layer constituting the surface of the liner requires wear resistance, it is desirable to use a wear-resistant alloy as in the past. However, by making the layers other than the surface layer into an alloy that is easy to deform, such as mild steel, the thermal stress can be absorbed and the residual stress can be reduced. For example, it is advisable to adopt 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.

[0012] (B) When the surface layer of the matrix is a wear-resistant alloy and the other layers are mild steel, this mild steel can be made into a steel plate. When forming the liner by the HIP method, since the shrinkage rate after HIP treatment is smaller for mild steel than for forming by powder metallurgy, forming with a mild steel plate can reduce the residual stress.

[0013] Furthermore, by pre-drilling holes for inserting the reinforcing material in the steel plate, not only is it easy to position the reinforcing material, but it is also possible to prevent the reinforcing material from moving during the HIP process. This can prevent displacement and inclination of the reinforcing material during the manufacturing process. If displacement or inclination of the reinforcing material occurs, unevenness will occur in the intervals between the reinforcing materials on the liner surface, and the portions with wider intervals will be selectively worn, which may lead to a shorter service life of the wear-resistant liner itself. Therefore, suppressing displacement and inclination of the wear-resistant reinforcing material contributes to extending the service life of the liner.

[0014] (c) By making the innermost layer on the back side of the steel, it becomes possible to join the wear-resistant liners together. The wear-resistant alloy on the surface layer of the liner (for example, high Cr alloy, high-speed steel, etc.) is difficult to weld, but if it is soft steel, it can be easily welded and joined. As a result of intensive research and development on the welding method by the present inventors, it has been found that if it is a welding method with a high input energy density such as electron beam welding or laser welding that locally generates heat, the liners can be welded without giving a thermal shock to the reinforcing material. Since the liners can be welded, even when a large liner is required, it is possible to manufacture it by dividing it into several parts and welding the back side of each liner.

[0015] (b) By making the liner into blocks of a size that is easy to manufacture and combining and welding the blocks according to the shape of the part where the liner is to be installed, a liner structure suitable for large-scale equipment and equipment with irregular shapes can be formed (hereinafter, the wear-resistant liner is used as a block, and the liner formed by combining these blocks is called a "liner structure"). By making the liner into blocks, the manufacturing equipment such as HIP equipment can be miniaturized. In addition, by standardizing the block shape, the productivity of the liner can be dramatically improved. Furthermore, the inspection equipment can also be miniaturized, and since existing inspection equipment can be used, it is also advantageous for quality control.

[0016] The present invention has been made based on the above findings, and the gist thereof is as follows. [1] The wear-resistant liner in which the wear-resistant reinforcing material is arranged in the matrix alloy, wherein the matrix alloy has two or more layers in the thickness direction of the wear-resistant liner over the entire length of the wear-resistant reinforcing material, Among the plurality of layers, the layer on the surface side of the wear-resistant liner closest to the surface is an alloy having wear resistance, and at least one of the other layers is mild steel. A wear-resistant liner characterized by this. [2] The wear-resistant liner according to [1], wherein the layer on the back side of the wear-resistant liner closest to the back side among the plurality of layers is mild steel. [3] The wear-resistant liner according to [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 rather than the wear-resistant reinforcing material 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 reinforcing material is at least one of ceramics and cemented carbide. [5] The wear-resistant liner according to any one of [1] to [4], wherein the alloy having wear resistance is at least one of a high Cr alloy and high speed steel. [6] The wear-resistant liner according to any one of [1] to [5], wherein the matrix alloy has one or two or more layers on the back side of the wear-resistant liner rather than the wear-resistant reinforcing material in the thickness direction of the wear-resistant liner. [7] The wear-resistant liner according to [6], wherein the layer on the back side of the wear-resistant liner closest to the back side among the plurality of layers and the layer on the back side of the wear-resistant liner rather than the wear-resistant reinforcing material are integrated. [8] A wear-resistant liner structure characterized by being composed of a plurality of wear-resistant liners according to any one of [1] to [7]. [9] The wear-resistant liner structure according to [8], wherein adjacent wear-resistant liners are joined at the back.

[10] The wear-resistant liner structure according to [8] or [9], wherein the joining is electron beam welding or laser welding.

[11] The wear-resistant liner structure according to any one of [8] to

[10] , wherein the joining is performed only on the layer constituting the back surface of the wear-resistant liner.

[12] A method for manufacturing a wear-resistant liner according to any one of [1] to [7], comprising: preparing a wear-resistant reinforcing material and a powder material of two or more alloys including at least an alloy having wear resistance and mild steel; arranging the powder material around the wear-resistant reinforcing material such that, in the thickness direction of the wear-resistant liner, the layer closest to the surface side of the wear-resistant liner becomes the alloy having wear resistance over the entire length of the wear-resistant reinforcing material; A method for manufacturing a wear-resistant liner, comprising HIP-treating the material in which the powder material is arranged around the wear-resistant reinforcing material.

[13] further, preparing a steel plate having an opening corresponding to a predetermined position for arranging the wear-resistant reinforcing material; The method for manufacturing a wear-resistant liner according to

[12] , comprising arranging the wear-resistant reinforcing material in the opening of the steel plate.

[14] further, preparing a steel plate having a recess in a portion corresponding to a predetermined position for arranging the wear-resistant reinforcing material; The method for manufacturing a wear-resistant liner according to

[12] , comprising arranging the wear-resistant reinforcing material in the recess of the steel plate.

[15] A method for manufacturing a wear-resistant liner structure according to any one of [8] to

[11] , comprising arranging a plurality of the wear-resistant liners adjacent to each other; and joining the adjacent wear-resistant liners at the back surface.

[16] The method for manufacturing a wear-resistant liner structure according to

[15] , wherein the joining is performed by electron beam welding or laser welding. [Effect of the Invention]

[0017] According to the present invention, in a wear-resistant liner composed of a wear-resistant reinforcing material made of ceramics, cemented carbide, etc. and a matrix alloy made of a wear-resistant alloy, etc., a wear-resistant liner in which cracks in the matrix alloy during the manufacturing process are suppressed can be obtained. This leads to an extended service life of the wear-resistant liner. Furthermore, according to the present invention, the wear-resistant liner can be made into small blocks, contributing to an improvement in the productivity and quality of the wear-resistant liner. Furthermore, it becomes possible to manufacture a large-sized wear-resistant liner by combining the small blocks.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0019] An embodiment of the present invention will be described with reference to the drawings.

[0020] [Wear-resistant Liner] FIG. 1 is a diagram showing an overview of an embodiment of a wear-resistant liner according to the present invention. The wear-resistant liner 1 according to this embodiment has a configuration in which a wear-resistant reinforcing material 3 is disposed so as to be embedded in a matrix alloy 2. The wear-resistant liner 1 usually has a plate-like shape, and one of its surfaces is a surface where powders such as steel raw materials and ores collide and contact and slide. This surface is referred to as the surface in this specification. And the opposite surface facing the surface is referred to as the back surface in this specification. The direction perpendicular to the surface is the thickness direction. Therefore, usually, wear resistance is imparted to the surface of the wear-resistant liner, and the long life of the liner is achieved. In FIG. 1, the case where the matrix alloy 2 has three layers (2a, 2b, 2c) over the entire length of the wear-resistant reinforcing material 3 in the thickness direction (sometimes simply referred to as the "thickness direction") of the wear-resistant liner 1 is shown.

[0021] FIG. 2 is a schematic view showing a cross section obtained by cutting the wear-resistant liner of FIG. 1 along AA. As can be seen when the wear-resistant liner is viewed in cross section, the reinforcing material 3 is disposed in the thickness direction of the liner and is disposed in the matrix alloy 2. Here, the total length 21 of the wear-resistant reinforcing material refers to the length from the surface of the reinforcing material 3 (the surface on the surface side of the wear-resistant liner) to the back surface of the reinforcing material 3 (the surface on the back surface side of the wear-resistant liner) in the thickness direction of the wear-resistant liner. In the example of FIG. 2, since the thickness of the liner and the length of the reinforcing material are the same, the surface of the reinforcing material constitutes a part of the liner surface, and the back surface of the reinforcing material constitutes a part of the liner back surface. In the example of FIG. 2, the matrix alloy has three layers (2a, 2b, 2c) over the entire length of the reinforcing material in the liner thickness direction.

[0022] Figure 3 is a conceptual diagram showing a cross-section of a liner in another embodiment. In the example of Figure 3, the reinforcing material 3 is completely embedded in the matrix alloy 2, and the reinforcing material 3 cannot be seen from the front or back surfaces of the liner. The matrix alloy 2 of the liner has four layers 2a, 2b, 2c, and 2d in order from the surface. The surface layer (the uppermost layer in the figure) 2a of the matrix alloy 2 is arranged so as to wrap the reinforcing material 3, is in contact with the surface of the reinforcing material 3, and is also in contact in the longitudinal direction of the reinforcing material 3. On the other hand, the back surface layer (the lowermost layer in the figure) 2d of the matrix alloy 2 is in contact with the back surface of the reinforcing material 3 but is not in contact in the longitudinal direction of the reinforcing material 3. In the case of the example of Figure 3, the matrix alloy 2 has three layers (2a, 2b, 2c) over the entire length of the reinforcing material 3 in the liner thickness direction.

[0023] Thus, as long as the layers arranged over the entire length of the reinforcing material in the matrix alloy are two or more multi-layers, any number and any layers on the front or back surface side of the liner than the reinforcing material may be provided. That being said, it remains desirable that the layer on the front surface side of the liner than the reinforcing material in the matrix alloy is an alloy having wear resistance. Among the matrix alloys, the layer on the back surface side of the liner than the reinforcing material is not limited in terms of its type or number of layers, but is preferably a mild steel layer for ease of handling and good bondability.

[0024] In the examples of Figures 1 to 3, the surface layer (the uppermost layer in the figure) 2a of the liner is preferably an alloy having wear resistance in order to form the liner surface. In the case of Figure 3, the liner surface is an alloy having wear resistance over the entire surface. However, as wear progresses, the surface of the reinforcing material is exposed, and eventually, it becomes the same form as in Figure 2.

[0025] Fig. 5 shows an overview of the structure of a conventional wear-resistant liner (for example, the liners in Patent Documents 1 and 2). As shown in Fig. 5, in the conventional liner, one layer, that is, one type of matrix alloy 2 is arranged over the entire length of the reinforcing material 3, and this is an alloy having wear resistance. Since the thermal expansion coefficients of the reinforcing material 3 such as ceramics and cemented carbide and the matrix alloy 2 which is a metal are very different, in the manufacturing process of the liner, the thermal shrinkage of the metal is large, and tensile residual stress is generated in the matrix alloy. This tensile residual stress causes cracking (cracks) in the matrix alloy.

[0026] Therefore, the matrix alloy is made into a multi-layer structure so as to absorb the thermal shrinkage difference between the reinforcing material such as ceramics and cemented carbide and the matrix alloy during liner manufacturing. Therefore, for the alloy constituting the matrix alloy, the outermost layer is an alloy having wear resistance, but it is desirable that the other layers are alloys having high deformability and capable of absorbing the thermal shrinkage difference. High deformability means that it deforms without breaking even when stress is applied. For example, alloys with a large fracture strain such as mild steel are preferred. Although light metals such as aluminum also have high deformability, their melting points are low, and it is difficult to combine them with, for example, wear-resistant steel. Therefore, it is generally preferable to use mild steel. Here, mild steel generally refers to steel having a tensile strength of 490 Mpa or less and a carbon (C) content of 0.30 mass% or less. If it is mild steel, the fracture strain is large and the deformability is also high. Therefore, by putting a layer of mild steel in the matrix alloy arranged over the entire length of the reinforcing material, the thermal shrinkage difference can be absorbed during the liner manufacturing process, and the tensile residual stress in the matrix alloy can be reduced.

[0027] On the other hand, for example, in a case where a layer of mild steel is further added to the back side of the liner composed of one layer of the wear-resistant alloy in Fig. 5, since the matrix alloy arranged over the entire length of the reinforcing material is only the alloy having wear resistance, even if a layer of mild steel is added to the back side, the thermal shrinkage difference between the reinforcing material and the matrix alloy cannot be absorbed. Therefore, it is important that the matrix alloy is a multi-layer of two or more layers over the entire length of the reinforcing material, and it is preferable that one of the layers is mild steel.

[0028] More preferably, the mild steel layer may be the layer on the back side of the wear-resistant liner among the plurality of matrix alloy layers. When one side of the reinforcing material is mild steel, it is easy to absorb the thermal shrinkage difference, and the handling property and joining property are excellent as described later.

[0029] Although described with the example of FIG. 3, among the matrix alloys, there may be a layer on the back side of the liner from the reinforcing material, and it is particularly preferably a mild steel layer. Therefore, both the layer on the back side (for example, 2c in FIG. 3) of the matrix alloy arranged over the entire length of the reinforcing material and the layer on the back side of the liner from the reinforcing material (for example, 2d in FIG. 3) may be mild steel. Of course, these layers (for example, 2c and 2d in FIG. 3) may be mild steel of the same material or may be integral. 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 reinforcing material and the layer arranged on the back side of the reinforcing material are the same. It is preferable that this layer (the layer on the back side) is mild steel because it is easy to absorb the thermal shrinkage difference and the handling property and joining property are improved.

[0030] The type of the matrix alloy is not particularly limited. Which alloy is applied to which layer is not limited. It may be selected from the structure of the liner, the target powder, ore, etc. The matrix alloy arranged on the outermost surface of the liner is preferably an alloy having wear resistance, but its material is not particularly limited. Examples of alloys having wear resistance include high Cr cast iron containing 12 to 30 wt% Cr and 1 to 3 wt% C and added with Si, Mn, Ni, Cu, Mo, W, etc., and high speed steel (various alloys of high speed tool steel, JIS standard SKH). One of these may be selected, or they may be combined in a composite manner.

[0031] As the reinforcing material, ceramics, cemented carbide, etc. can be used. The type of ceramics is not particularly limited, and for example, it may be Si3N4, sialon, SiC, ZrO2, Al2O3, etc. The cemented carbide is also not particularly limited, and for example, it may be not only WC-Co, but also a composite carbide obtained by adding TiC, TaC, etc. to WC, or a material in which Co is replaced with Ni, Ni-Cr, Ni-Mo, etc. That is, it is preferably at least one of ceramics and cemented carbide, and both may be used. Also, the shape of the wear-resistant reinforcing material is not particularly limited. The reinforcing materials shown in FIGS. 1 to 4 are square columnar, but are not limited thereto. For example, it may be cylindrical, frustum-shaped, etc. There are also those having the shapes shown in Patent Documents 1 and 3. From the viewpoint of wear resistance, it is preferable that the area of the surface of the reinforcing material on the liner surface side (the surface constituting the liner surface) is large. However, if the area of the surface of the reinforcing material is large, the area of the matrix alloy becomes narrow accordingly. If there is no appropriate matrix alloy between the reinforcing materials, the reinforcing materials will collide with each other, causing damage to the reinforcing materials and increasing the cost of the reinforcing materials. The size to which it should be made may be appropriately determined according to the size and hardness of the target powder and ore.

[0032] [Wear-resistant liner structure] The wear-resistant liner is used for equipment protection, and its size and shape are determined according to each equipment. Usually, it is manufactured integrally according to each equipment. However, in order to manufacture a large liner or a liner with a complex shape integrally, not only large manufacturing equipment (for example, HIP equipment) is required, but also defect inspection equipment such as cracks is enlarged, resulting in not only a decrease in productivity but also an increase in the cost of the manufacturing equipment. Therefore, these problems can be solved by combining small wear-resistant liners as blocks.

[0033] The inventors have found that by combining a plurality of the above-described wear-resistant liners as blocks, a wear-resistant liner suitable for large equipment and equipment with irregular shapes can be efficiently manufactured. A structure of a wear-resistant liner suitable for large equipment and equipment with irregular shapes composed of a plurality of these wear-resistant liners (blocks) is called a wear-resistant liner structure.

[0034] For example, a plurality of wear-resistant liners having a standard shape, which are wear-resistant liners that can be manufactured by existing HIP equipment, are manufactured, and these standard wear-resistant liners (blocks) are arranged and joined together so as to conform to the shape of the equipment to which the liner is to be attached, whereby a large-sized wear-resistant liner (wear-resistant liner structure) can be manufactured.

[0035] FIG. 6 shows an example of a wear-resistant liner having a two-layer matrix alloy. This may be considered as the intermediate layer 2b among the layers of the matrix alloy shown in FIG. 4 becoming the surface layer 2a. Therefore, the surface layer 2a of the matrix alloy in FIG. 6 is an alloy having wear resistance, and the layer 2c on the back side is a layer of mild steel. A case where this wear-resistant liner is used as a standard wear-resistant liner (block) will be described as an example.

[0036] FIG. 7 is a diagram showing an example of a wear-resistant liner structure formed by combining five standard wear-resistant liners (blocks) of FIG. 6. By arbitrarily combining the blocks in this way, other wear-resistant liner structures of various shapes can be manufactured. By joining adjacent blocks together, an integrated wear-resistant liner structure can be obtained. The blocks are preferably joined on the back surface. If joined on the liner surface, since it is exposed to the wear environment, the joined portion will wear and become separated. When joining on the back surface of the liner, if the matrix alloy on the back side is mild steel, the joining becomes easier. For example, in the case of welding mild steel, existing welding methods can be applied, and it can be welded more easily compared to wear-resistant steel and the like.

[0037] The joining method is not particularly limited. The above-described welding may be used, or mechanical joining may also be acceptable. Since the back surface is not exposed to the wear environment, even if an existing joining method is applied, the joined portion 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 heat input, it may affect wear-resistant reinforcements such as ceramics and cemented carbides, so a welding method with a high heat density and appropriate heat control such as laser welding or electron beam welding is preferably used.

[0038] Also, in the case of laser welding or electron beam welding, since the heat-affected zone is limited, it is possible to join without affecting wear-resistant reinforcing materials such as ceramics and cemented carbide. Furthermore, in the case of laser welding or electron beam welding, since the shape of the back surface can be welded as it is, it becomes easier to attach the integrated wear-resistant liner structure to the equipment.

[0039] Fig. 8 shows an example of laser welding a standard liner. Fig. 8 is a view looking at the back surface of the liner. Six square blocks are arranged in the front, and their boundaries are laser welded. Also, the laser welding is joined only within the layer (in the case of Fig. 8, the mild steel layer) that constitutes the back surface of the matrix alloy. By joining only the mild steel layer, a highly reliable joint can be obtained. Since the back surface of the liner is not exposed to the wear environment, sufficient strength can be obtained even with welding of only the mild steel layer, and the blocks will not come off during use.

[0040] [Manufacturing method] An embodiment of the manufacturing method of the wear-resistant liner will be described. The manufacturing method is not limited as long as it can satisfy the requirements of the wear-resistant liner and the requirements of the wear-resistant liner structure defined in the present invention. What is described here is an example of the manufacturing method. The wear-resistant liner can be manufactured by powder metallurgy, specifically, hot pressing or HIP (Hot Isostatic Press) method. Hereinafter, taking the manufacturing of the wear-resistant liner of Fig. 3 by the HIP method as an example will be described.

[0041] Prepare the powder of the alloy that will be the matrix alloy. For example, when making the first layer (2a in Fig. 3) from a high Cr alloy, the second layer (2b) from an alloy combining a high Cr alloy and mild steel, the third layer (2c) from mild steel, and the fourth layer (2d) from mild steel with a reduced carbon content compared to the third layer from the surface of the liner, prepare the powder of each alloy. There are no particular limitations on the powder preparation method and the properties of the powder. Alloy powder can be prepared by applying well-known alloy powdering techniques. On the other hand, also prepare the reinforcing material. As described above, the material and shape of the reinforcing material are not particularly limited. It may be manufactured according to the required specifications.

[0042] To perform HIP, alloy powder serving as the fourth layer is introduced into the capsule and spread out in layers. Next, the wear-resistant reinforcing material is arranged at a predetermined position. Next, the alloy powder of the third layer, the alloy powder of the second layer, and then the alloy powder of the first layer are introduced in layers in this order so that the arranged reinforcing material does not shift in position. After introducing the alloy powder, the capsule is sealed and the inside of the capsule is depressurized. By depressurization, a vacuum state is formed inside the capsule.

[0043] Subsequently, the capsule is loaded into a HIP apparatus and HIP treatment is performed. The conditions for HIP treatment may be appropriately selected according to the well-known HIP method. For example, heating (for example, 1200°C to 1400°C) and pressurization (for example, 250 MPa to 600 MPa) may be performed. Thereby, the powder material is sintered by HIP treatment. After the HIP treatment is completed, the capsule is taken out from the HIP apparatus, the capsule is removed, and the liner is formed to obtain a wear-resistant liner having a desired shape. Note that when the capsule is heated and pressurized to manufacture the liner, the liner will shrink, which is natural in the HIP method and can be foreseen in advance. Therefore, the capsule and the amount of alloy powder may be determined in consideration of the shrinkage allowance. This may also be applied by the well-known HIP method.

[0044] It is also possible to use a plate material of the alloy instead of the alloy powder. For example, instead of the mild steel of the third layer in the above example, a mild steel plate may be used. In this case, the mild steel plate is pre-punched at the location where the reinforcing material will be arranged. And after introducing the alloy powder of the fourth layer (corresponding to the lowermost part) in layers, the mild steel plate serving as the third layer is arranged on the fourth layer, the reinforcing material is arranged in the plate opening, and the alloy powder of the second layer and the alloy powder of the first layer may be introduced in order. By making the third layer a mild steel plate having openings, not only is it easy to position the reinforcing material, but it is also possible to prevent the reinforcing material from shifting or tilting during HIP treatment. Since the steel plate has less shrinkage during HIP treatment than the alloy powder, the shape of the steel plate may be determined in advance by foreseeing this shrinkage.

[0045] Also, when the third layer and the fourth layer in the above example are made of the same mild steel, they can be regarded as one layer and a steel plate can be applied to this layer. That is, the structure will be as shown in Fig. 4. When the third layer (2c in Fig. 4) is made of a steel plate, recesses are formed in advance in the mild steel plate at the locations where the reinforcing materials are to be arranged. Then, the mild steel plate with the recesses formed therein is placed in the capsule, and then the reinforcing materials are inserted and arranged in the recesses. Thus, similar to the above example, it is possible to prevent the displacement and inclination of the reinforcing materials during the HIP process. Since the shrinkage of the steel plate during the HIP process is smaller than that of the alloy powder, the shape of the steel plate can be determined by predicting this shrinkage in advance. Also, the mild steel plate that becomes this third layer (the bottom layer) can be used as a part of the capsule used for the HIP process.

[0046] Above, an example of the manufacturing method of the wear-resistant liner according to the present invention has been described. Next, the manufacturing method of the wear-resistant liner structure will be described with 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 these blocks are combined to manufacture a wear-resistant liner structure. For example, as shown in Fig. 7, the wear-resistant liners are arranged adjacent to each other on a plane to form a liner structure of a desired size. At this time, each wear-resistant liner may be turned over so that the back surface is visible and then arranged. Next, the adjacent liners are joined. The joining method is not particularly limited, but when laser welding or electron beam welding is used, the input energy density is high, so the thermal load is not applied extensively and it does not affect wear-resistant reinforcing materials such as ceramics and cemented carbide. Also, if it is laser welding or electron beam welding, since the weld bead is small, it has the advantage of having little influence on the back surface shape. For the laser welding or electron beam welding of the back surface, only the layer of mild steel that constitutes the rearmost surface side needs to be welded. As long as it is within the range of the mild steel layer, welding is easy and no defects occur at the boundary of the alloy layer. Also, since the back surface of the liner is not exposed to the wear environment, the welded part does not wear, so the liner structure can be maintained for a long time.

[0047] In addition, by standardizing the liner into blocks, existing HIP devices and defect detection devices can be utilized. Also, by miniaturizing the liner (block), not only can the quality of the HIP process be improved, but shrinkage can also be kept small, thus improving the shape accuracy. Furthermore, the defect inspection system can be enhanced, and the detection accuracy of minute cracks can also be increased. From the above, there are significant advantages in quality control, and productivity can also be remarkably improved. By combining liners that become standard blocks, the wear-resistant liner according to the present invention can be applied to any equipment.

Example

[0048] As the wear-resistant liner according to the present invention, a liner was prepared in which the matrix alloy has a first layer of high Cr cast iron and a second layer of mild steel from the liner surface layer. That is, it corresponds to the combination of the second layer (2b in FIG. 4) and the third layer (2c) in FIG. 4. As test materials, those prepared with all matrix alloys using alloy powders (test material 1), those using mild steel plates with apertures (test material 2), those using mild steel plates with recesses (test material 3), and as a comparative example, those with the matrix alloy consisting only of high Cr cast iron (comparison) were each manufactured in seven pieces by the HIP method. The reinforcing material and the liner shape are as shown below.

[0049] Ceramic wear-resistant reinforcing material: Si3N4 W22mm × D22mm × H37mm Wear-resistant liner dimensions: W74mm × D74mm × H45mm Arrangement of reinforcing materials in the wear-resistant liner: 3 × 3 = 9 pieces are arranged when viewed from the liner surface

[0050] After manufacturing, an appearance inspection was carried out, and the presence or absence of cracks in the matrix alloy was confirmed by the fluorescent flaw detection method. The results are shown in Table 1.

Table 1

[0051] Next, a plurality of each of the test materials 1 to 3 manufactured above were arranged in a horizontal row, and adjacent liners were electron beam welded to manufacture a wear-resistant liner assembly. Fig. 8 shows an example of the manufactured liner assembly. On the front side of Fig. 8, six square liners are arranged in a row. The rectangular part and the rod-shaped protrusion on the back side of Fig. 8 are jig parts for fixing the liner to the target equipment and have nothing to do with the present invention. The electron beam welding only reaches the mild steel layer part of the liner and does not reach the high Cr cast iron layer on the surface side. Further, as a comparative example, a wear-resistant liner with a matrix alloy of only high Cr cast iron was manufactured by the HIP method in the same manner as before for a liner of the same size (the same size as the liner formed by arranging six of the test materials 1 to 3 in a row). In the production of the conventional product as a comparative example, cracks occurred in the matrix alloy, deteriorating the product yield. Eventually, out of the five manufactured liners as a comparative example, only two without cracks were obtained.

[0052] Next, it was installed in an actual iron-making blast furnace and a wear resistance comparison test was conducted. As the liner of the swivel chute, which is equipment for charging steel raw materials into the blast furnace, the liner assemblies each composed of the test materials 1 to 3 and the conventional integrally formed liner as a comparative example were attached to the inner surface of the swivel chute, and the actual equipment was operated to check the wear situation. After about six months of continuous operation, the liner was removed and the wear situation was visually inspected. As a result, the liner assemblies composed of the test materials 1 to 3 and the integrally formed liner of the conventional product had almost the same wear situation. This is because, as the liner structure, the ceramic wear-resistant reinforcement is arranged in the high Cr cast iron, so they are all the same. However, when observed in detail, in the liner assembly of the test material 1 and the integrally formed liner of the conventional product, the parts where the displacement of the reinforcement occurred and the parts where the interval between the reinforcements widened were selectively worn. In the liner assemblies composed of the test materials 2 and 3, the arrangement of the reinforcements was uniform, and selective wear of the high Cr cast iron serving as the joint did not occur.

Industrial Applicability

[0053] The present invention can be used in all industries that utilize powders, ores, etc.

Description of Symbols

[0054] 1 Wear-resistant liner 2 Matrix alloy 2a, 2b, 2c, 2d Each layer of the matrix alloy 3 Wear-resistant reinforcement 11 Wear-resistant liner structure 21 Total length of the wear-resistant reinforcement

Claims

1. A wear-resistant liner in which a wear-resistant reinforcing material is disposed in a matrix alloy, wherein the matrix alloy has two or more layers over the entire length of the wear-resistant reinforcing material in the thickness direction of the wear-resistant liner, and among the plurality of layers, the layer closest to the surface side of the wear-resistant liner is an alloy having wear resistance, and at least one of the other layers is mild steel. A wear-resistant liner characterized by this.

2. The wear-resistant liner according to claim 1, wherein the layer closest to the back side 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 rather than the wear-resistant reinforcing material in the thickness direction of the wear-resistant liner.

4. The wear-resistant liner according to any one of claims 1 to 3, wherein the wear-resistant reinforcing material is at least one of ceramics and cemented carbide.

5. The wear-resistant liner according to any one of claims 1 to 4, wherein the alloy having wear resistance is at least one of a high Cr alloy and high speed steel.

6. The wear-resistant liner according to any one of claims 1 to 5, wherein the matrix alloy has one or two or more layers on the back side of the wear-resistant liner rather than the wear-resistant reinforcing material in the thickness direction of the wear-resistant liner.

7. The wear-resistant liner according to claim 6, wherein the layer closest to the back side of the wear-resistant liner among the plurality of layers and the layer on the back side of the wear-resistant liner rather than the wear-resistant reinforcing material are integrated.

8. A wear-resistant liner structure characterized by being composed of the wear-resistant liner according to any one of claims 1 to 7.

9. The wear-resistant liner structure according to claim 8, wherein adjacent wear-resistant liners are joined at the back.

10. The wear-resistant liner structure according to claim 9, wherein the joining is electron beam welding or laser welding.

11. The wear-resistant liner structure according to claim 9 or 10, wherein the joining is performed only with 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 claims 1 to 7, the steps of preparing a powder material of two or more alloys including a wear-resistant reinforcing material, and at least an alloy having wear resistance and mild steel. In the thickness direction of the wear-resistant liner, arranging the powder material around the wear-resistant reinforcing material so that the layer closest to the surface side of the wear-resistant liner becomes an alloy having the wear resistance over the entire length of the wear-resistant reinforcing material; A method for manufacturing a wear-resistant liner, comprising the step of HIP-treating a structure in which the powder material is arranged around the wear-resistant reinforcing material.

13. Furthermore, a step of preparing a steel plate having an opening corresponding to a predetermined position where the wear-resistant reinforcing material is to be arranged; The method for manufacturing a wear-resistant liner according to claim 12, comprising the step of arranging the wear-resistant reinforcing material in the opening of the steel plate.

14. Furthermore, a step of preparing a steel plate having a recess in a portion corresponding to a predetermined position where the wear-resistant reinforcing material is to be arranged; The method for manufacturing a wear-resistant liner according to claim 12, comprising the step of arranging the wear-resistant reinforcing material in the recess of the steel plate.

15. A method for manufacturing a wear-resistant liner structure according to any one of claims 8 to 11, comprising the step of arranging a plurality of the wear-resistant liners adjacent to each other; A method for manufacturing a wear-resistant liner structure, comprising the step of joining the adjacent wear-resistant liners on the back surface.

16. 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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