Hearth component and method for manufacturing hearth component

Abstract

The hearth component of the present invention has a furnace exposed surface exposed in the incinerator, the furnace exposed surface has a front surface and an upper surface, and a protective layer having grooves formed on the surface is provided at least on the front surface.

Description

Technical Field

[0001] The present invention relates to a hearth component and a method for manufacturing the hearth component. Background Art

[0002] The so-called grate is a component of the hearth arranged at the bottom of the incinerator. It has the function of stirring and transporting the garbage while burning it by moving back and forth. As for the material of the grate, SCH2, which is a heat-resistant cast steel, is generally used, and it is mainly manufactured by casting. In addition, in Japanese Patent No. 6730814, a grate is proposed, which is manufactured by joining plates having a first alloy layer and a second alloy layer to each other by welding. In the incinerator, the incineration ash and the incombustibles are mixed together, and the thickness of the grate is reduced mainly due to the corrosion of chlorine in the garbage and the wear caused by contact with hard incombustibles. Generally speaking, the life of the grate is about 3 to 6 years. In order to continue to use the incinerator, the grate needs to be replaced regularly, but since each grate is quite heavy, the cost required for replacement is very high. Therefore, it is required to extend the life of the grate.

[0003] Japanese Patent Application Laid-Open No. 7-4634 proposes that a grate body be formed of cast iron or high-Cr cast steel, and a wear-resistant material formed of a Co-based alloy be plasma-welded on the surface of a hanging portion of the grate body that hangs down from at least one end of the flat portion for conveying garbage. Summary of the invention

[0004] It is desirable to provide a hearth component part and a method for manufacturing a hearth component part that can extend the life of the hearth component part.

[0005] A hearth component according to one embodiment of the present invention has a furnace exposed surface exposed in the incinerator.

[0006] In the hearth components,

[0007] The furnace exposed surface has a front surface and an upper surface,

[0008] A protective layer having grooves formed on the surface is provided at least on the front surface.

[0009] In the method for manufacturing a hearth component according to one embodiment of the present invention,

[0010] The hearth component has a furnace exposed surface exposed in the incinerator, the furnace exposed surface has a front surface and an upper surface, and a protective layer having grooves formed on the surface is provided at least on the front surface.

[0011] The method for manufacturing the hearth component includes the step of forming the protective layer on a main body composed of a casting or a plate by laser build-up welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A This is a schematic diagram showing the structure of an incineration facility according to one embodiment.

[0013] Figure 1B This is a diagram showing a schematic structure of a bottom portion of an incinerator according to an embodiment.

[0014] Figure 2 It is a perspective view showing a schematic structure of a hearth component according to an embodiment.

[0015] Figure 3 This is a photograph of the hearth components of one embodiment taken from the front and obliquely above.

[0016] Figure 4 This is a magnified photograph of the front surface of the hearth component according to one embodiment.

[0017] Figure 5 This is a view showing a cross section obtained by cutting the protective layer of the hearth component member according to one embodiment along a plane perpendicular to the extending direction of the grooves.

[0018] Figure 6 This is a graph showing the test results of a corrosion wear resistance test on a protective layer of a hearth component.

[0019] Figure 7 It is a perspective view showing a schematic structure of a hearth component according to a modification of the embodiment.

[0020] Figure 8 It is a magnified representation Figure 7 A diagram showing a protective member among the components of a hearth.

[0021] Fig. 9 Yes means Figure 2 A perspective view of a modified example of the hearth component shown.

[0022] Fig.10 Yes means Figure 7 A perspective view of a modified example of the hearth component shown. DETAILED DESCRIPTION

[0023] A hearth component according to a first aspect of the embodiment has a furnace exposed surface exposed in the incinerator.

[0024] In the hearth components,

[0025] The furnace exposed surface has a front surface and an upper surface,

[0026] A protective layer having grooves formed on the surface is provided at least on the front surface.

[0027] According to this method, since a protective layer is provided on at least the front surface of the furnace bed component exposed in the furnace, the front surface of the furnace bed component body will not be directly exposed to the corrosive gas and incombustibles in the incinerator, and the thickness reduction caused by corrosion mainly due to chlorine in the garbage and wear caused by contact with hard incombustibles can be prevented. In addition, grooves are formed on the surface of the protective layer, and the corrosion products are peeled off due to wear at the ridges between the grooves. However, since the peeled microparticles, dust or small-sized incombustibles will accumulate on the inner surface of the groove, the inner surface of the groove will not be directly exposed to the corrosive gas in the incinerator and the large-sized incombustibles that affect wear, it is difficult to reduce the thickness due to corrosion and wear, and thus the overall thickness reduction of the protective layer can be suppressed. Therefore, it is possible to extend the life of the furnace bed component.

[0028] When the protective layer is combined with an air cooling or water cooling structure for cooling the hearth components, the protective layer is substantially cooled to a temperature below the metal temperature at which thickness reduction due to corrosion and wear is unlikely to occur, thereby further extending the life of the protective layer.

[0029] In addition, it is generally difficult to measure the thickness reduction of the hearth component. Although the relative thickness reduction with other hearth components is basically evaluated, the thickness reduction of the hearth component that is welded with an alloy having corrosion resistance and wear resistance is small, and it is impossible to judge the extent of the thickness reduction of the weld layer in the relative evaluation. In this regard, according to the first method, since the groove is formed on the surface of the protective layer, it has the advantage of being able to visually confirm the thickness reduction and judge the approximate life of the hearth component. Furthermore, by adjusting the depth of the groove, it is easy to find out the timing of replacement or repair.

[0030] In a hearth component according to a second aspect of the embodiment, according to the hearth component according to the first aspect,

[0031] The protective layer is also provided on at least a portion of the upper surface on the front surface side.

[0032] According to this aspect, since the protective layer is also provided on the upper surface of the furnace-exposed surface of the hearth component, even on the upper surface, the protective layer prevents the grate body from reducing in thickness, and since the protective layer has grooves formed on the surface, the reduction in thickness of the protective layer as a whole can be suppressed. Thus, the life of the hearth component can be further prolonged.

[0033] In a hearth component according to a third aspect of the embodiment, the hearth component according to the first or second aspect,

[0034] The width of the groove is 5 mm or less.

[0035] The inventor of this case conducted a composition analysis of the garbage in the incinerator and found that the average size of the incombustibles (hard incombustibles, etc.) that affect wear is about 5 mm. Therefore, when the width of the groove is greater than 5 mm, in addition to being difficult to accumulate tiny particles, dust or small-sized incombustibles in the groove, it is also easy to collide with the entire surface of the hard incombustibles. In this regard, according to the third embodiment, since the width of the groove is less than 5 mm, it is difficult for hard incombustibles to collide with the inner surface of the groove, and the inner surface of the groove is difficult to be worn. In this way, it is possible to seek to further extend the life of the components of the furnace bed.

[0036] In a hearth component according to a fourth aspect of the embodiment, the hearth component according to any one of the first to third aspects,

[0037] The protective layer has the following alloy composition, that is, when the protective layer as a whole is set to 100 mass%, it contains 10 mass% to 50 mass% of Cr, 0 mass% to 50 mass% of Fe, 0 mass% to 10 mass% of Mo, 0 mass% to 5 mass% of Si, 0.05 mass% to 1 mass% of C, 0 mass% to 5 mass% of Cu, 0 mass% to 1 mass% of Co, 0 mass% to 7 mass% of B, and the remainder is composed of Ni and unavoidable impurities.

[0038] According to this aspect, since the corrosion resistance and wear resistance of the protective layer are improved, the life of the hearth component parts can be further prolonged.

[0039] In a hearth component according to a fifth aspect of the embodiment, the hearth component according to any one of the first to fourth aspects,

[0040] The thickness of the protective layer is 1.0-1.2 mm.

[0041] In a hearth component according to a sixth aspect of the embodiment, the hearth component according to any one of the first to fifth aspects,

[0042] The depth of the groove is 0.2-0.4 mm.

[0043] In a hearth component according to a seventh aspect of the embodiment, the hearth component according to any one of the first to sixth aspects,

[0044] The protective layer is formed by laser cladding.

[0045] According to this method, for example, when a protective layer is directly formed on the surface of a main body (parent material) composed of a casting, thermal deformation and dilution of the main body (parent material) of the casting can be suppressed because the heat input is less than that of plasma cladding and arc cladding. In addition, when the material of the main body (parent material) composed of a casting is SCH2 with poor weldability, the parent material will crack if it is not preheated in advance during plasma cladding and arc cladding, but there is a problem that preheating requires time and cost. In response to this, by forming a protective layer using laser cladding, cracking of the main body (parent material) and protective layer (cladding material) composed of the casting can be suppressed while omitting the preheating that was originally required. Furthermore, grooves can be easily formed on the surface of the protective layer during construction, and there is no need for mechanical processing after construction.

[0046] In the hearth component according to an eighth aspect of the embodiment, the hearth component according to any one of the first to seventh aspects,

[0047] The main body is a casting or a plate, and the front surface and the upper surface of the plate have a first alloy layer and a second alloy layer.

[0048] The material of the main body composed of a casting may also be SCH2.

[0049] The material of the first alloy layer of the body composed of a plate material is, for example, 5-6C-28-32Cr-2-3Nb-3-5W alloy, or an alloy having higher heat resistance, corrosion resistance and / or wear resistance than the second alloy layer. The material of the second alloy layer can also be a common structural rolled steel plate or stainless steel plate with excellent weldability.

[0050] In a hearth component according to a ninth aspect of the embodiment, the hearth component according to any one of the first to eighth aspects,

[0051] having a side surface in contact with the front surface and the upper surface,

[0052] The protective layer is also provided on at least the front surface side of the side surface.

[0053] The thickness of the protective layer on the side surface is smaller than the thickness of the protective layer on the front surface.

[0054] In a hearth component according to a tenth aspect of the embodiment, the hearth component according to any one of the first to ninth aspects,

[0055] The protective layer is formed directly on the surface of the main body composed of a casting or a plate.

[0056] In the hearth component according to an eleventh aspect of the embodiment, the hearth component according to any one of the first to eighth aspects,

[0057] The invention also includes a protective member that can be attached to and detached from the front surface and the upper surface of the main body formed of a casting or a plate.

[0058] The protection layer is formed on the surface of the protection member.

[0059] In the hearth component of a twelfth aspect of the embodiment, according to the hearth component of the eleventh aspect,

[0060] The material of the protective member is SUS.

[0061] A grate according to a thirteenth aspect of the embodiment is a grate constituted by the hearth constituent member according to any one of the first to twelfth aspects.

[0062] A side grate according to a fourteenth aspect of the embodiment is a side grate constituted by the hearth constituent member according to any one of the first to twelfth aspects.

[0063] A sealing block according to a fifteenth aspect of the embodiment is a sealing block formed of the hearth component according to any one of the first to twelfth aspects.

[0064] A protective member according to a 16th aspect of the embodiment is detachable from a front surface and an upper surface of a main body formed of a casting or a plate in a hearth component, wherein the hearth component has a furnace exposed surface exposed in an incinerator, the furnace exposed surface having a front surface and an upper surface, and a protective layer having grooves formed on the surface is provided at least on the front surface.

[0065] In the protective member,

[0066] The protection layer is formed on the surface of the protection member.

[0067] An incineration facility according to a seventeenth aspect of the embodiment includes the hearth component according to any one of the first to twelfth aspects.

[0068] In the method for manufacturing a hearth component according to an eighteenth aspect of the embodiment,

[0069] The hearth component has a furnace exposed surface exposed in the incinerator, the furnace exposed surface has a front surface and an upper surface, and a protective layer having grooves formed on the surface is provided at least on the front surface.

[0070] The method for manufacturing the hearth component includes the step of forming the protective layer on a main body composed of a casting or a plate by laser build-up welding.

[0071] Hereinafter, specific examples of the embodiments will be described in detail with reference to the drawings. It should be noted that in the following description and the drawings used in the following description, the same reference numerals are used for parts that can have the same configuration, and repeated descriptions are omitted.

[0072] Figure 1A It is a schematic diagram showing the structure of an incineration facility 10 according to one embodiment.

[0073] like Figure 1A As shown, the incineration facility 10 includes: a platform 21 for parking a transport vehicle (garbage truck) 22 loaded with waste; a garbage pit 3 for storing waste thrown in from the platform 21; a crane 5 for mixing and transporting the waste stored in the garbage pit 3; a hopper 4 for throwing in the waste carried by the crane 5; an incinerator 1 for incinerating the waste thrown in from the hopper 4; and a waste heat boiler 2 for recovering waste heat from waste gas generated in the incinerator 1. The structure of the garbage pit 3 is not limited to Figure 1A The first-level pit shown also includes the second-level pit.

[0074] The waste carried in the state of being loaded in the transport vehicle 22 is thrown into the garbage pit 3 from the platform 21 and stored in the garbage pit 3. The waste stored in the garbage pit 3 is stirred by the crane 5, and is transported to the hopper 4 by the crane 5, and is thrown into the incinerator 1 through the hopper 4, and is incinerated in the incinerator 1.

[0075] Figure 1B 1 is a diagram showing a schematic structure of the bottom of the incinerator 1. In this embodiment, Figure 1B As shown, the type of incinerator 1 is a stoker furnace. Inside the incinerator 1, across the furnace wall 11, fixed grates 12 and movable grates 14 are alternately arranged in a step-like manner along the flow direction of the garbage. Figure 1B In the figure, only one side of the furnace wall 11 is depicted. An end grate 16 is arranged at the upstream end of these grates 12 and 14. The fixed grate 12 is fixed to a fixed frame 18, and the movable grate 14 is fixed to a movable frame 26 that reciprocates with the help of wheels 22 and rails 24 as the hydraulic cylinder 20 works. Furthermore, a scraper 28 is installed on the fixed grate 12 and the movable grate 14 to slide on the upper surface of the fixed grate 12 or the movable grate 14 located below.

[0076] In addition, a pair of side grates 30 are arranged at positions of the furnace wall 11 that are opposite to the end faces of the fixed grate 12, the movable grate 14, and the end grate 16, respectively, and a sealing block 32 (also called a side seal) is arranged above each side grate 30. In FIG1, only one side grate 30 and one side sealing block 32 arranged above the grate are depicted.

[0077] Thus, as the movable grate 14 reciprocates, the garbage hopper 4 (see Figure 1A) is mixed with the waste (garbage) put in, and the waste is transported downward in sequence and burned. At this time, the end faces of the fixed grate 12, the movable grate 14 and the end grate 16 are pressed against the surface of the side grate 30 to seal it, and the sealing block 32 seals the gap between the side grate 30 and the furnace wall 11.

[0078] like Figure 1B As shown, the grates 12, 14, the side grates 30 and the sealing block 32 each have a furnace exposed surface exposed in the incinerator 1, and the furnace exposed surface has a front surface 61a and an upper surface 61b (refer to the following description). Figure 2 ). The front surface of the side grate 30 is opposite to the end surfaces (side surfaces) of the grates 12 and 14.

[0079] In the incinerator 1 having such a structure, one or more of the grates 12, 14, the side grates 30 and the sealing block 32 may also be constituted by the hearth component 6 described later. The hearth component 6 may also be cooled by air or water. Specifically, for example, the structure described in Japanese Patent No. 3838639 can be adopted as an air-cooling or water-cooling structure for cooling the hearth component 6. Hereinafter, a representative description will be given of the hearth component 6 constituting the grates 12, 14, but as long as it is a hearth component having an exposed surface in the furnace exposed in the incinerator 1, it is not limited to the grates 12, 14, and the technology of this embodiment can be applied to all.

[0080] Figure 2 It is a perspective view showing a schematic structure of the hearth component 6 according to the present embodiment. Figure 3 This is a photograph of the hearth component 6 taken from the front and obliquely above. Figure 4 This is a magnified photograph of the front surface of the hearth component 6 .

[0081] like Figures 2 to 4 As shown, the hearth component 6 has a main body 61 made of a casting or a plate, and a protective layer 62. When the main body 61 is made of a casting, heat-resistant cast steel such as SCH2 can also be used as the material of the main body 61 made of a casting. When the main body 61 is made of a plate, the plate can also have a second alloy layer and a first alloy layer located on the exposed surface side of the furnace compared to the second alloy layer. The material of the first alloy layer of the main body made of the plate can also be 5~6C-28~32Cr-2~3Nb-3~5W alloy. The material of the second alloy layer can also be a common structural rolled steel plate or stainless steel plate with excellent weldability.

[0082] like Figures 2 to 4As shown, the protective layer 62 is provided on at least the front surface 61a of the main body 61 formed of a casting or a plate. Since the protective layer 62 is provided on the front surface 61a of the main body 61 formed of a casting or a plate, the portion of the front surface 61a of the grate main body 61 covered by the protective layer 62 is not directly exposed to the corrosive gas and incombustibles in the incinerator 1, and the thickness can be prevented from being reduced mainly due to corrosion by chlorine in the garbage and wear caused by contact with hard incombustibles.

[0083] exist Figures 2 to 4 In the example shown, the protective layer 62 is provided in a manner covering the entire front surface 61a of the main body 61 formed of a casting or a plate, but the present invention is not limited thereto. Fig. 9 As shown, the protective layer 62 may be provided except for the lower part of the front surface 61a. In this case, when the entire front surface 61a of the main body 61 formed of a casting or a plate is 100%, the protective layer 62 may be provided in a range of 50% or more from the upper side (i.e., excluding the range of less than 50% from the lower side), 80% or more (i.e., excluding the range of less than 20% from the lower side), 90% or more (i.e., excluding the range of less than 10% from the lower side), or 95% or more (i.e., excluding the range of less than 5% from the lower side). In the case where the protective layer 62 is provided on the entire front surface 61a of the hearth component 6, since the lower end of the protective layer 6 is in contact with the upper surface of the lower hearth component, when the hearth component 6 moves forward and backward, the upper surface of the lower hearth component may be scraped off. On the other hand, when the protective layer 62 is provided except for the lower portion of the front surface 61a of the hearth component 6, the lower end of the protective layer 6 does not contact the upper surface of the lower hearth component, so that the thickness reduction of the upper surface of the lower hearth component can be suppressed.

[0084] like Figure 2 and Figure 3 As shown, the protective layer 62 may also be provided on at least the portion on the front surface 61a side of the upper surface 61b of the main body 61 formed of a casting or a plate. In this case, the upper surface 61b of the grate main body 61 will not be directly exposed to the corrosive gas and incombustibles in the incinerator 1, and the thickness reduction due to corrosion and wear can be prevented. It should be noted that the so-called "portion on the front surface 61a side" may be a range of less than 15% from the front surface 61a side when the entire upper surface 61b is 100%, a range of less than 10%, or a range of less than 8%.

[0085] like Figure 3 to Figure 4 As shown in FIG. 6 , grooves 63 are formed on the surface of the protective layer 62. Figure 3 , Figure 4In the example shown, a plurality of straight grooves 63 parallel to the left-right direction are arranged in a longitudinally adjacent manner, but are formed only in a manner covering the surface of the protective layer 62, and the planar pattern of the grooves 63 is not limited thereto. For example, a plurality of wavy grooves 63 winding along the left-right direction may be arranged in a longitudinally adjacent manner, a plurality of concentrically formed quadrilateral grooves 63 of gradually different sizes may be formed, or a single groove 63 may be formed in a square spiral shape extending from the center to the outer edge. Figure 5 It is a plane perpendicular to the extending direction of the groove ( Figure 4 FIG. 6 is a cross-sectional view of the protective layer 62 cut along the AA line in FIG. 6 .

[0086] In this embodiment, since grooves 63 are formed on the surface of the protective layer 62, the corrosion products are peeled off due to wear at the ridgeline 64 between the grooves 63, but since the peeled microparticles, dust or small-sized incombustibles are accumulated on the inner surface of the groove 63, the inner surface of the groove 63 is not directly exposed to the corrosive gas in the incinerator 1 and the large-sized incombustibles that affect wear, and the thickness reduction due to corrosion and wear is unlikely to occur. Therefore, the overall thickness reduction of the protective layer 62 can be suppressed.

[0087] Generally speaking, it is difficult to measure the thickness reduction of the hearth component. Although the relative thickness reduction with other hearth components is basically evaluated, the thickness reduction of the hearth component that is welded with an alloy having corrosion resistance and wear resistance is small, and it is impossible to judge the extent to which the thickness of the weld layer has been reduced in the relative evaluation. In this regard, according to the present embodiment, since the groove 63 is formed on the surface of the protective layer 62, it has the advantage of being able to visually confirm the thickness reduction and judge the approximate life of the hearth component 6. In addition, by adjusting the depth D2 of the groove 63, it is easy to find out the timing of replacement or repair of the grate 6. Specifically, for example, for a hearth component 6 with a protective layer 62 having a thickness of 1.2 mm and a groove 63 having a depth of 0.4 mm, if it is assumed that the groove 63 disappears in 6 years, it can be judged that the remaining service life is about 10 years.

[0088] like Figure 5 As shown, the thickness D1 of the protective layer 62 is, for example, 1.0 to 1.2 mm. The depth D2 of the groove 63 can be appropriately adjusted according to the timing of replacement or repair, but may be, for example, 0.2 to 0.4 mm.

[0089] The width D3 of the groove 63 may also be less than 5 mm. Here, the width D3 of the groove 63 refers to the distance between two adjacent ridges 64. The width D3 of the groove 63 is equal to the center interval of two adjacent grooves 63. The inventor of the present case conducted a composition analysis of the garbage in the incinerator 1, and found that the average size of the incombustibles (hard incombustibles, etc.) that affect wear is about 5 mm. Therefore, when the width of the groove is greater than 5 mm, in addition to being difficult to accumulate tiny particles, dust or small-sized incombustibles in the groove, it is also easy to collide with the entire surface of hard incombustibles. In response to this, as in the present embodiment, when the width D3 of the groove 63 is less than 5 mm, since the incombustibles in the garbage are difficult to collide with the inner surface of the groove 63, the inner surface of the groove 63 becomes more difficult to be worn.

[0090] Alternatively, the grate body 61 may include a side surface 61c connected to the front surface 61a and the upper surface 61b, and the protective layer 62 may also be provided on at least a portion of the side surface 61c of the grate body 61 on the side of the front surface 61a. In this case, the thickness of the protective layer 62 on the side surface 61c may be smaller than the thickness of the protective layer 62 on the front surface 61a.

[0091] The material of the protective layer 62 is not particularly limited as long as it is a material with corrosion resistance and wear resistance. For example, it can also have the following alloy composition (hereinafter sometimes referred to as the first alloy composition), that is, when the entire protective layer is set to 100 mass%, it contains 10 mass% to 50 mass% of Cr, 0 mass% to 50 mass% of Fe, 0 mass% to 10 mass% of Mo, 0 mass% to 5 mass% of Si, 0.05 mass% to 1 mass% of C, 0 mass% to 5 mass% of Cu, 0 mass% to 1 mass% of Co, 0 mass% to 7 mass% of B, and the remainder is Ni and unavoidable impurities.

[0092] Hereinafter, the reasons for the composition of each element in the above-mentioned first alloy composition will be described.

[0093] [Cr: 10 mass % or more and 50 mass % or less]

[0094] The content of Cr may also be 10% by mass or more and 50% by mass or less, preferably 10% by mass or more and 35% by mass or less, and more preferably 15% by mass or more and 25% by mass or less. Cr is an indispensable element for maintaining corrosion resistance at high temperatures. If it is less than 10% by mass, sufficient corrosion resistance cannot be exerted. Cr forms precipitates (Cr boride and Cr carbide) with B and C to increase the hardness of the protective layer 63, thereby improving wear resistance. On the other hand, if the content of Cr is too much, it will cause deterioration of workability due to an increase in the melting point, so it is preferably 50% by mass as the upper limit.

[0095] [Ni: 0 mass % or more and 70 mass % or less]

[0096] The content of Ni can also be more than 0 mass% and less than 70 mass%, preferably less than 50 mass%. It is known that Ni has excellent corrosion resistance, especially excellent high-temperature chlorination corrosion characteristics. It is generally believed that the more Ni content, the better the material properties. On the other hand, since Ni is expensive, it is hoped to reduce the amount of addition from a cost perspective. The applicant in this case found from the corrosion test results of Ni-Fe-Cr alloy that: when the contained chlorine partial pressure is low, the corrosion resistance is improved when Ni is contained; when the Ni content exceeds 70 mass%, the corrosion resistance is greatly reduced. Therefore, the content of Ni is upper limited to 70 mass%.

[0097] [Mo: 0 mass % or more and 10 mass % or less]

[0098] The content of Mo can also be 0% by mass or more and 10% by mass or less, preferably 0% by mass or more and 3% by mass or less or 3% by mass or more and 5% by mass or less. In a chlorinated corrosion environment represented by a waste incinerator, Alloy 625 containing 9% by mass of Mo is known to exhibit excellent corrosion resistance. However, if the content of Mo exceeds 10% by mass, it is known that the corrosion resistance will deteriorate instead. Moreover, when the Mo content increases, the workability also deteriorates. On the other hand, with regard to corrosion resistance and wear resistance, if the content of Mo is reduced, although only a little, the result is that the thickness reduction is suppressed. In the case of attaching importance to workability and corrosion resistance and wear resistance, it is preferably set to suppress the Mo content of 0% by mass or more and 3% by mass or less; in the case of attaching importance to corrosion resistance, it is preferably set to 3% by mass or more and 5% by mass or less.

[0099] [C: 0.05 mass % or more and 1 mass % or less]

[0100] The content of C can also be 0.05% by mass or more and 1% by mass or less, preferably 0.3% by mass or more and 0.7% by mass or less. Since C forms hard Cr carbides, etc., it is generally used to increase the hardness of the protective film. The precipitation phase centered on Cr carbides is prominent, which helps to improve the corrosion resistance and wear resistance by alleviating the wear of the parent material. When the content of C is less than 0.05% by mass, the precipitation of the Cr carbide phase is insufficient, but if it exceeds 1% by mass, the Cr in the parent material will be over-consumed as carbides, and there is a risk of deterioration of corrosion resistance.

[0101] [Cu: 0 mass % or more and 5 mass % or less]

[0102] The content of Cu may be 0 mass % or more and 5 mass % or less. By adding Cu to the Ni-based self-fluxing alloy, the corrosion resistance can be improved.

[0103] [Co: 0 mass % or more and 1 mass % or less]

[0104] The content of Co may be 0 mass % or more and 1 mass % or less. By adding a small amount of Co to the Ni-based alloy, the parent phase γNi can be strengthened. On the other hand, since Co is expensive, it is desirable to reduce the amount of addition from a cost perspective, and preferably 1 mass % is the upper limit.

[0105] [B: 0 mass % or more and 10 mass % or less]

[0106] The content of B can also be 0% by mass or more and 10% by mass or less, preferably 2% by mass or more and 7% by mass or less, and more preferably 5% by mass or more and 6% by mass or less. B is an indispensable element for workability (remelting property), and forms Cr boride in the alloy of the parent material to help solidify the alloy. When the alloy formed with Cr boride is exposed to a corrosive environment, corrosion products will be formed on the metal parent material. Here, since it is related to wear, the corrosion products will be damaged, the corrosion rate will increase, and the thickness reduction of the parent material can be promoted as a result. As a result, the hard and wear-resistant Cr boride protrudes, and will preferentially be hit by ash and incombustibles, and the wear conditions of the parent material will be alleviated, and it can be considered that the thickness reduction of the parent material will be suppressed. However, if the content of B is too much, the Cr consumed as a boride will increase, and therefore, the corrosion resistance of the parent material will be reduced, and because the parent material is too hard and brittle, it is preferably 10% by mass as the upper limit. Cr carbide also has the same effect, but it is Cr boride that plays the main role in the above-mentioned alloy composition.

[0107] [Si: 0 mass % or more and 5 mass % or less]

[0108] The content of Si may also be 0% by mass or more and 5% by mass or less, preferably more than 0% by mass and less than 2% by mass, more preferably 0.1% by mass or more and less than 1.5% by mass. It is known that Si helps to improve oxidation resistance. However, if the content of Si is high, the corrosion resistance and wear resistance will be reduced. It is known that the corrosion resistance will be reduced in an environment containing a trace amount of chlorine. As described above, it is desirable to not contain Si from the perspective of corrosion resistance, wear resistance and corrosion resistance. Therefore, it is preferred to add Si with an upper limit of 5%.

[0109] exist Figure 2In the example shown, the protective layer 62 is directly formed on the surface of the main body 61 composed of a casting or a plate. The protective layer 62 can also be formed on the main body 61 composed of a casting or a plate by laser cladding (also called laser cladding). In this case, since the heat input is less than that of plasma cladding and arc cladding, thermal deformation and dilution of the main body 61 (parent material) composed of a casting or a plate can be suppressed. In addition, in the case where the material of the main body 61 (parent material) composed of a casting is SCH2 with poor weldability, the parent material will crack if it is not preheated in advance during plasma cladding and arc cladding, but there is a problem that preheating requires time and cost. In response to this, by forming the protective layer 62 by laser cladding, it is possible to suppress the cracking of the main body 61 (parent material) composed of the casting and the protective layer 62 (cladding material) while omitting the preheating that is originally required. Furthermore, when the protective layer 62 is formed by laser build-up welding, since the groove 63 can be easily formed on the surface of the protective layer 62 during construction, there is an advantage that no additional machining is required to form the groove 63 after construction.

[0110] As a variation, Figure 7 and Figure 8 As shown, the hearth component 6 may also include a protective member 65 that can be installed and removed relative to the front surface 61a and the upper surface 61b of the main body 61 composed of a casting or a plate, and the protective layer 62 is formed on the surface of the protective member 65. The material of the protective member 65 may be, for example, a SUS material. The protective layer 62 may also be formed on the surface of the protective member 65 by laser cladding (laser cladding). In this case, since the heat input is less than that of plasma cladding and arc cladding, thermal deformation and dilution of the protective member 65 (parent material) can be suppressed. In addition, when the protective layer 62 is formed by laser cladding, since the groove 63 can be easily formed in a manner covering the surface of the protective layer 62 during construction, there is an advantage that no additional machining is required to form the groove 63 after construction.

[0111] A method for manufacturing a hearth component 6 according to a modified example will be described. Figure 8 As shown in FIG. 6 , a protective layer 62 is formed on the surface of the protective member 65. Next, as shown in FIG. Figure 7 As shown, the protective member 65 is connected to the main body 61 made of a casting or a plate by welding. In this way, a modified example of the hearth component 6 can be manufactured. In the hearth component 6 of a modified example, when the thickness of the protective layer 62 is reduced, the protective layer 62 can be replaced by cutting off the welded portion and replacing it with a new protective member 65, which has the advantage of not removing the hearth component 6 from the incinerator 1.

[0112] It should be noted that in Figures 7 and 8In the example shown, the protective layer 62 is formed in a manner that covers the entire front surface 61a of the protective member 65, but is not limited thereto. Fig.10 As shown, the lower part of the front surface 61a may be excluded. In this case, when the entire front surface 61a of the protective member 65 is 100%, the protective layer 62 may be provided in a range of 50% or more from the upper side (i.e., excluding the range of less than 50% from the lower side), 80% or more (i.e., excluding the range of less than 20% from the lower side), 90% or more (i.e., excluding the range of less than 10% from the lower side), or 95% or more (i.e., excluding the range of less than 5% from the lower side). In the case where the protective layer 62 is provided on the entire front surface 61a of the protective member 65, since the lower end of the protective layer 6 is in contact with the upper surface of the hearth component below, when the hearth component 6 to which the protective member 65 is attached moves forward and backward, the upper surface of the hearth component below may be scraped off. On the other hand, when the protective layer 62 is provided except for the lower portion of the front surface 61a of the protective member 65, the lower end of the protective layer 6 does not contact the upper surface of the lower hearth component, so that the thickness of the upper surface of the lower hearth component can be suppressed from decreasing.

[0113] According to the present embodiment as described above, since the protective layer 62 is provided on at least the front surface 61a of the furnace exposed surface of the hearth component 6, the front surface 61a of the main body 61 composed of a casting or a plate is not directly exposed to the corrosive gas and incombustibles in the incinerator 1, and the thickness reduction caused by corrosion mainly due to chlorine in the garbage and wear caused by contact with hard incombustibles can be prevented. In addition, the protective layer 62 has grooves 63 formed on the surface, and the corrosion products are peeled off due to wear at the ridges 64 between the grooves 63 and the grooves 63, but the peeled fine particles, dust or small-sized incombustibles are accumulated on the inner surface of the grooves 63, so the inner surface of the grooves 63 is not directly exposed to the corrosive gas in the incinerator 1 and the large-sized incombustibles that affect wear, and the thickness reduction caused by corrosion and wear is unlikely to occur, so the thickness reduction of the protective layer 62 as a whole can be suppressed. Therefore, the life of the hearth component 6 can be extended. In addition, according to this embodiment, since the groove 63 is formed on the surface of the protective layer 62, there is an advantage that the thickness reduction can be visually confirmed and the approximate life of the hearth component 6 can be determined. Furthermore, by adjusting the depth D2 of the groove 63, the timing of replacement or repair can be easily determined.

[0114] Next, specific examples of this embodiment will be described.

[0115] The inventor of this case first used five materials, namely, Ni-based developed material, SFNi4, Inconel (registered trademark) 625, Stellite (registered trademark) 21, and DHECR-TB2 (registered trademark), as cladding materials (powders), and performed laser cladding on a main body 61 composed of SCH2, thereby forming a protective layer 62 having grooves 63 formed in a manner of covering the surface. Here, the so-called Ni-based developed material is an alloy having a composition described in Technical Solution 1 of Japanese Patent No. 6745735. The alloy composition of SFNi4 is specified by JIS H8303: 2010. The so-called DHECR-TB2 is an alloy having a composition described in Technical Solution 1 of Japanese Patent No. 7044328. Among them, the Ni-based developed material, SFNi4 and DHECR-TB2 are materials that satisfy the above-mentioned first alloy composition.

[0116] Secondly, the corrosion and wear resistance of the protective layer 62 composed of various materials was measured using the following method. That is, in the actual incinerator, especially in the combustion zone where the grate is severely damaged, two grates composed of five castings with the above five materials laser-welded as protective layers 62 on the exposed surface in the furnace and a new grate (grate without protective layer) composed of existing materials (SCH2) were irregularly arranged, and the incinerator was operated in this state. The test period was half a year. In addition, after the test, the weight change (i.e., thickness reduction) before and after the test was measured for each grate.

[0117] Figure 6 This is a graph showing the measurement results of the thickness reduction of various grates (the average value of the thickness reduction of each of the two grates for each grate). Figure 6 As shown, the thickness reduction of the grate without a protective layer (previous product) is about 1.4 kg, while the thickness reduction of the grate with a protective layer 62 is less than 0.4 kg in any material. It is confirmed that the thickness reduction can be greatly suppressed by providing a protective layer 62 on the exposed surface of the grate in the furnace.

[0118] In addition, the inventor of this case installed a grate consisting of a plate with DHECR-TB2 laser-welded in an actual incinerator, especially in the combustion zone where the grate was severely damaged, and operated the incinerator in this state. The test period was half a year. Moreover, after the test, the weight change (i.e., thickness reduction) before and after the test was measured for each grate, and the result confirmed that it was the same thickness reduction as above, and the thickness reduction was suppressed regardless of the material of the base material.

[0119] The above embodiments and modifications are described by way of example, but the technical scope of the present invention is not limited thereto, and the embodiments and modifications can be changed and modified according to the purpose within the scope described in the technical claims. In addition, the embodiments and modifications can be appropriately combined within the scope of not contradicting the processing contents.

Claims

1. A hearth component having a furnace exposed surface exposed in an incinerator, The hearth component is characterized in that: The furnace exposed surface has a front surface and an upper surface, A protective layer having grooves formed on the surface is provided at least on the front surface.

2. The hearth component according to claim 1, characterized in that: The protective layer is also provided on at least a portion of the upper surface on the front surface side.

3. The hearth component according to claim 1 or 2, characterized in that: The width of the groove is 5 mm or less.

4. The hearth component according to any one of claims 1 to 3, characterized in that: The protective layer has the following alloy composition, that is, when the protective layer as a whole is set to 100 mass%, it contains 10 mass% to 50 mass% of Cr, 0 mass% to 50 mass% of Fe, 0 mass% to 10 mass% of Mo, 0 mass% to 5 mass% of Si, 0.05 mass% to 1 mass% of C, 0 mass% to 5 mass% of Cu, 0 mass% to 1 mass% of Co, 0 mass% to 7 mass% of B, and the remainder is composed of Ni and unavoidable impurities.

5. The hearth component according to any one of claims 1 to 4, characterized in that: The thickness of the protective layer is 1.0-1.2 mm.

6. The hearth component according to any one of claims 1 to 5, characterized in that: The depth of the groove is 0.2-0.4 mm.

7. The hearth component according to any one of claims 1 to 6, characterized in that: The protective layer is formed by laser cladding.

8. The hearth component according to any one of claims 1 to 7, characterized in that: It is cooled by air cooling or water cooling.

9. The hearth component according to any one of claims 1 to 8, characterized in that: Having a main body composed of a casting or a main body composed of a plate, The front surface and the upper surface of the plate have a first alloy layer and a second alloy layer.

10. The hearth component according to claim 9, characterized in that: The material of the main body composed of castings is SCH2. The material of the first alloy layer of the main body composed of a plate material is an alloy having higher heat resistance, corrosion resistance and / or wear resistance than that of the second alloy layer. The material of the second alloy layer is a common structural rolled steel plate or a stainless steel plate.

11. The hearth component according to any one of claims 1 to 10, characterized in that: having a side surface connected to the front surface and the upper surface, The protective layer is also provided on at least the front surface side of the side surface. The thickness of the protective layer on the side surface is smaller than the thickness of the protective layer on the front surface.

12. The hearth component according to any one of claims 1 to 11, characterized in that: The protective layer is formed directly on the surface of the main body composed of a casting or a plate.

13. The hearth component according to any one of claims 1 to 12, characterized in that: The invention also includes a protective member that can be attached to and detached from the front surface and the upper surface of the main body formed of a casting or a plate. The protection layer is formed on the surface of the protection member.

14. The hearth component according to claim 13, characterized in that: The material of the protective member is SUS.

15. A grate, characterized in that: The hearth component comprises the hearth component according to any one of claims 1 to 13.

16. A side grate, characterized in that: The hearth component comprises the hearth component according to any one of claims 1 to 13.

17. A sealing block, characterized in that: The hearth component comprises the hearth component according to any one of claims 1 to 13.

18. A protective member that can be attached and detached to the front surface and the upper surface of a main body formed of a casting or a plate in a hearth component, the hearth component having a furnace exposed surface exposed in an incinerator, the furnace exposed surface having a front surface and an upper surface, and a protective layer having grooves formed on the surface at least on the front surface, The protective member is characterized in that The protection layer is formed on the surface of the protection member.

19. An incineration facility, characterized in that: A hearth component according to any one of claims 1 to 13 is provided.

20. A method for manufacturing a hearth component, the hearth component having a furnace exposed surface exposed in an incinerator, the furnace exposed surface having a front surface and an upper surface, a protective layer having grooves formed on the surface at least on the front surface, The method for manufacturing the hearth component is characterized in that: The method comprises the step of forming the protective layer on a body composed of a casting or a plate by laser cladding.

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