A near net shape method for impact wheels

Abstract

The application discloses a near-net forming method of an impact runner, and the method is used for overflow forming a bucket unit and other castings in a variable surface passage of an electroslag casting crystallizer through multi-electrode synchronous melting. A consumable electrode is inserted into an electrode passage of the electroslag casting crystallizer, the position of the electrode passage into which the consumable electrode is inserted is selected according to the cross-section position of the electroslag casting crystallizer, and the number of the electrode passages into which the consumable electrode is inserted is selected according to the cross-sectional area of the electroslag casting crystallizer. The number of the electrode passages is multiple, and the electrode passages are dispersedly distributed along the cross-section of the electroslag casting crystallizer; the multiple consumable electrodes are synchronously subjected to electroslag casting; the metal melt formed by melting of the multiple consumable electrodes passes through a slag pool and enters a molten pool; one side of the molten pool fills the cross-section of an overflow passage of the electroslag casting crystallizer; and the one side of the molten pool rises, so that the forming of special-shaped castings is realized, and the limitation that the electroslag casting in the prior art can only form simple castings is broken.

Description

Technical Field

[0001] This application relates to the field of materials thermal processing technology, and in particular to a near-net-shape forming method for an impact roller. Background Technology

[0002] In existing technologies, electroslag remelting can form castings with simple structures, such as ingots, but it cannot form irregularly shaped components. Summary of the Invention

[0003] This application proposes a near-net-shape forming method for impact rollers to achieve the forming of irregularly shaped components.

[0004] To achieve the above objectives, this application provides a near-net-shape forming method for an impact roller, comprising:

[0005] S101. Design an electroslag casting crystallizer according to the shape and size of the water bucket unit, and determine the number of electrode channels of the electroslag casting crystallizer according to the width of the water bucket unit and the thickness of the overflow channel of the electroslag casting crystallizer, and manufacture the electroslag casting crystallizer.

[0006] The water bucket unit is a unit formed by dividing the impact wheel along the plane where the water bucket's opening end is located. The water bucket unit can be 1 / 2 water bucket, 3 / 4 water bucket, the entire water bucket, the entire water bucket plus part of the spokes, or the entire water bucket plus spokes corresponding to the position of the entire water bucket.

[0007] S102. Prepare a consumable electrode according to the dimensions of the electrode channel;

[0008] S103. Multiple consumable electrodes are simultaneously subjected to electroslag casting so that the molten metal formed by electroslag casting overflows and forms a preform in the overflow channel of the electroslag casting crystallizer.

[0009] S104. Heat-treat the preform to obtain the water tank unit.

[0010] Preferably, in the above-described near-net-shape forming method for the impact wheel, step S103 includes:

[0011] S1031. A mixture of steel scrap and slag is laid at the bottom of the electroslag casting crystallizer;

[0012] S1032. A portion of the multiple consumable electrodes simultaneously initiate arc slag formation to obtain a stable slag pool filling the cross-section of the electroslag casting crystallizer.

[0013] S1033. Multiple consumable electrodes are simultaneously subjected to electroslag casting, and the molten metal formed by electroslag casting overflows and forms in the overflow channel of the electroslag casting crystallizer to obtain the preform.

[0014] Preferably, in the near-net-shape forming method of the impact rotor described above, the slag material is a pentagonal slag, which includes CaF2, Al2O3, CaO, MgO and SiO2, wherein the mass percentage of CaF2 is 10%-30%, the mass percentage of Al2O3 is 25%-35%, the mass percentage of CaO is 20%-30%, the mass percentage of MgO is 4%-8%, and the mass percentage of SiO2 is 2%-10%.

[0015] Preferably, in the near-net-shape forming method of the impact wheel described above, in step S103, the filling ratio of the plurality of consumable electrodes is 0.2-0.45.

[0016] Preferably, in the near-net-shape forming method of the impact wheel described above, in step S103, the furnace mouth voltage of the electroslag casting is 70-90V and the current is 2000-40000A.

[0017] Preferably, the near-net-shape forming method of the impact wheel described above further includes S105, located between S103 and S104, for shrinkage compensation.

[0018] Preferably, in the above-described near-net-shape forming method for the impact wheel, step S105 specifically comprises:

[0019] S1051. The electroslag casting current is reduced at a constant rate to the minimum feeding current, and the minimum feeding current is maintained for a first preset time.

[0020] S1052, the minimum feeding current is uniformly increased to the maximum casting current, and the maximum casting current is maintained for a second preset time, wherein the maximum casting current is 60%-80% of the electroslag casting current;

[0021] S1053, Repeat S1051-S1052 at least 3 times, and use the highest melting and casting current as the electroslag melting and casting current for the next current change;

[0022] S1054, the electroslag casting current is reduced to 0A at a constant rate.

[0023] Preferably, in the near-net-shape forming method of the impact wheel described above, the inner lining of the electroslag casting crystallizer is a copper inner lining, the outer shell of the electroslag casting crystallizer is a carbon steel plate outer shell, a cooling cavity is formed between the inner lining and the outer shell, and the cooling cavity is separated into cooling channels by a partition plate, the partition plate being an aluminum alloy plate.

[0024] Preferably, in the above-described near-net-shape forming method for the impact wheel, step S104 includes:

[0025] S1041, Stress annealing;

[0026] S1042, Normalizing;

[0027] S1043, two tempering processes.

[0028] Preferably, in the near-net-shape forming method of the impact wheel described above, the consumable electrode is made of AOD refined steel liquid; and / or,

[0029] The consumable electrode is manufactured using rolling, metal mold solidification, or steel plate welding processes.

[0030] The near-net-shape forming method for impact turbines provided in this application involves multi-electrode synchronous melting, overflow forming of castings such as water tank units within the curved surface channel of an electroslag casting crystallizer. Consumable electrodes are inserted into the electrode channels of the electroslag casting crystallizer. The position of the electrode channels is selected based on the cross-sectional position of the electroslag casting crystallizer, and the number of electrode channels is selected based on the cross-sectional area of ​​the electroslag casting crystallizer. Multiple electrode channels are distributed along the cross-section of the electroslag casting crystallizer. Multiple consumable electrodes simultaneously undergo electroslag casting. The molten metal formed by the melting of multiple consumable electrodes passes through the slag pool and enters the molten pool. The molten pool fills the cross-section of the overflow channel of the electroslag casting crystallizer on one side and rises on the other, achieving the forming of irregularly shaped castings. This breaks the limitation of existing electroslag casting, which can only form simple castings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort, and this application can be applied to other similar scenarios based on the provided drawings. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0032] Figure 1 These are structural schematic diagrams of different disassembly forms of the water bucket unit in this application;

[0033] Figure 2 This is a schematic diagram of the electroslag casting crystallizer of this application;

[0034] Figure 3 This is a top view of the electroslag casting crystallizer of this application;

[0035] Figure 4 This is a schematic diagram of the internal cavity of the electroslag casting crystallizer of this application;

[0036] Figure 5This is a front view of the inner cavity of the electroslag casting crystallizer of this application;

[0037] Figure 6 This is a schematic diagram of the structure of a portion of the electrode channel of the electroslag casting crystallizer of this application into which a consumable electrode is inserted;

[0038] Figure 7 This is a schematic diagram of the structure of the electroslag casting crystallizer of this application, in which multiple electrode channels are inserted into consumable electrodes;

[0039] Figure 8 This is a flowchart of the near-net-shape forming method for the impact wheel of this application.

[0040] in:

[0041] 1. Water bucket unit, 2. Electroslag casting crystallizer, 3. Consumable electrode. Detailed Implementation

[0042] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. The described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0043] It should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0044] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used in this application are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0045] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0046] In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more.

[0047] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0048] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed precisely in sequence. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0049] Water bucket unit 1 is an irregularly shaped component with a non-uniform thickness three-dimensional curved surface. It adopts a crystallizer electroslag melting casting water bucket blank in the form of integral or block combination structure, with a large post-processing allowance and low material utilization rate.

[0050] Please see Figures 1-8 This application discloses a near-net-shape forming method for impact rollers, which can realize the casting forming of irregularly shaped parts.

[0051] This application uses the near-net-shape of the water bucket unit 1 of the impact impeller as an example for illustration. Water bucket unit 1 is the water bucket structure required by the manufacturer, such as... Figure 1 As shown, the water bucket unit 1 can be 1 / 2 water bucket, 3 / 4 water bucket, the entire water bucket, the entire water bucket plus part of the spoke plate, or the entire water bucket plus the entire spoke plate corresponding to the position of the entire water bucket. The spoke plate can have structures such as positioning pins or positioning grooves.

[0052] The near-net-shape forming method of the impact wheel disclosed in this application involves multi-electrode synchronous melting, and overflow forming of castings such as water bucket unit 1 in the variable surface channel of electroslag casting crystallizer 2.

[0053] The near-net-shape forming method for the impact roller disclosed in this application includes:

[0054] S101. Design the electroslag casting crystallizer 2 according to the shape and size of the water bucket unit 1, and determine the number of electrode channels of the electroslag casting crystallizer 2 according to the width of the water bucket unit 1 and the thickness of the overflow channel of the electroslag casting crystallizer 2, and manufacture the electroslag casting crystallizer 2.

[0055] S102. Prepare the consumable electrode 3 according to the size of the electrode channel;

[0056] S103, Multiple consumable electrodes 3 are simultaneously electroslag casting to overflow and form in the overflow channel of electroslag casting crystallizer 2 to obtain preforms;

[0057] S104, heat-treated prefabricated parts, to obtain water tank unit 1.

[0058] Among them, water bucket unit 1 is a unit formed by dividing the impact wheel along the plane where the opening end of the water bucket is located. Water bucket unit 1 can be 1 / 2 water bucket, 3 / 4 water bucket, the whole water bucket, the whole water bucket + part of the spokes, or the whole water bucket + spokes corresponding to the position of the whole water bucket.

[0059] The near-net-shape forming method for the impact rotor disclosed in this application involves inserting consumable electrodes 3 into the electrode channels of the electroslag casting crystallizer 2. The position of the electrode channels into which the consumable electrodes 3 are inserted is selected based on the cross-sectional position of the electroslag casting crystallizer 2, and the number of electrode channels into which the consumable electrodes 3 are inserted is selected based on the cross-sectional area of ​​the electroslag casting crystallizer 2. Taking the near-net-shape forming water tank unit 1 as an example, as... Figure 2 As shown, the electroslag casting crystallizer 2 is equipped with five electrode channels, which are respectively located on the two sides of the water tank, the water-dividing blade, and the back reinforcing rib. (Refer to...) Figure 6 and Figure 7 The first part to be formed is the lower part of the water tank unit 1, which is located in the middle of the electroslag casting crystallizer 2. At this time, three consumable electrodes 3 need to be inserted into the three electrode channels corresponding to the water dividing blade and the back reinforcing rib. As the molten pool rises, the middle and lower part of the water tank unit 1 needs to be formed. At this time, two consumable electrodes 3 need to be inserted into the electrode channels on the two sides of the corresponding water tank.

[0060] Due to the limitations of the shape and size of the overflow channel of the electroslag casting crystallizer 2, the consumable electrode 3 cannot be inserted into the overflow channel. In this application, an electrode channel is provided on the electroslag casting crystallizer 2, and the consumable electrode 3 is inserted into the electrode channel.

[0061] There are multiple electrode channels, which are distributed along the cross-section of the electroslag casting crystallizer 2. Multiple consumable electrodes 3 perform electroslag casting simultaneously. One side of the molten pool fills the cross-section of the overflow channel of the electroslag casting crystallizer 2, while the other side of the molten pool rises to form a casting.

[0062] This application employs multiple consumable electrodes 3 to simultaneously perform electroslag casting. The molten metal formed by the melting of multiple consumable electrodes 3 passes through the slag pool and enters the molten pool, and flows to fill the cross-section of the cavity of the electroslag casting crystallizer 2, thereby achieving the forming of irregularly shaped castings.

[0063] In some embodiments of this application, S103 includes:

[0064] S1031. Lay a mixture of steel scrap and slag at the bottom of the electroslag casting crystallizer 2;

[0065] S1032. A portion of the multiple consumable electrodes 3 simultaneously initiate arc slag formation to obtain a stable slag pool that fills the cross-section of the electroslag casting crystallizer 2.

[0066] S1033, multiple consumable electrodes 3 simultaneously perform electroslag casting, and the molten metal formed by electroslag casting overflows and forms a preform in the overflow channel of the electroslag casting crystallizer 2.

[0067] In S1031, the mass ratio of steel scrap to slag is 3:1. However, the mass ratio of steel scrap to slag is not limited to 3:1 and can be adjusted appropriately according to the composition of the slag.

[0068] The mixture of steel scrap and slag is evenly spread at the bottom of the electroslag casting crystallizer 2 with a thickness of 20-50mm to ensure that multiple consumable electrodes 3 can start arcing synchronously.

[0069] S1032 is to form a stable slag pool that fills the entire cross-section of the electroslag casting crystallizer 2, thus protecting the molten pool. In some embodiments of this application, the filling ratio of the consumable electrode 3 in S1032 is 0.24.

[0070] After the stabilized slag pool is formed, proceed to step S1033.

[0071] In S1033, multiple consumable electrodes 3 are simultaneously electroslag cast and formed by overflow within the overflow channel. In some embodiments of this application, the filling ratio of the consumable electrodes 3 in S1033 is 0.31.

[0072] In some embodiments of this application, the filling ratio of the multiple consumable electrodes 3 is 0.2-0.45, which ensures that the molten metal formed by the multiple consumable electrodes 3 during melting and rising can flow and fill the cross-section of the cavity of the electroslag casting crystallizer 2, thereby improving the quality of electroslag casting.

[0073] The filling ratio is the ratio of the total cross-sectional area of ​​the consumable electrodes 3 located in the electroslag casting crystallizer 2 to the cross-sectional area of ​​the electroslag casting crystallizer 2.

[0074] The near-net-shape forming method for the impact rotor disclosed in this application uses a pentagonal slag material, which includes CaF2, Al2O3, CaO, MgO and SiO2. The mass percentage of CaF2 is 10%-30%, the mass percentage of Al2O3 is 25%-35%, the mass percentage of CaO is 20%-30%, the mass percentage of MgO is 4%-8%, and the mass percentage of SiO2 is 2%-10%.

[0075] The slag material disclosed in this application has a low melting point, high electrical resistance, and is weakly acidic. Compared with binary slag CaF2-Al2O3, it can improve the forming quality, enhance electrical efficiency, and is beneficial to the plasticity and toughness of the material.

[0076] This application uses pentagonal slag as an arc initiator instead of conventional TiO2 arc initiator, thus avoiding slag contamination.

[0077] Preferably, the amount of slag added is no more than 15% of the total mass of the slag system, and the thickness of the slag layer is 40-60% of the equivalent diameter of the electroslag casting crystallizer 2.

[0078] In S103, the furnace mouth voltage for electroslag casting is 70-90V, and the current is 2000-40000A.

[0079] The near-net-shape forming method for the impact turbine disclosed in this application uses a furnace mouth voltage approximately 40% higher than the conventional voltage. This ultra-high voltage allows the molten pool to rise, reducing the current while maintaining the same power, resulting in a shallower insertion depth of the consumable electrode 3 into the slag pool. The slag pool acts as a heat source to melt the electrode, and the slower melting rate of the consumable electrode 3 allows sufficient time for the molten pool to flow within the overflow channel. This ensures that the molten metal overflows and fills the cross-section of the electroslag casting crystallizer 2, guaranteeing the filling quality.

[0080] The current gradually increases from 2000A at the arc initiation point to the maximum cross-sectional area of ​​the water tank perpendicular to the casting direction. Figure 5 When AA is located, the current increases to 20000A, and the current growth rate is controlled by ±2000 of the current fluctuation value during the melting and casting process.

[0081] After the casting exceeds the maximum cross-sectional area, the current needs to be reduced.

[0082] During this process, the current is changed but the voltage remains unchanged, ensuring that the electroslag casting process is always at an ultra-high voltage.

[0083] The near-net-shape forming method for the impact roller disclosed in this application also includes S105, which is located between S103 and S104, for shrinkage compensation.

[0084] S105 specifically refers to:

[0085] S1051. The electroslag casting current is reduced at a constant rate to the minimum feeding current, and the minimum feeding current is maintained for a first preset time.

[0086] S1052. The minimum feeding current is increased at a constant rate to the maximum casting current, and the maximum casting current is maintained for a second preset time, wherein the maximum casting current is 60%-80% of the electroslag casting current;

[0087] S1053, repeat S1051-S1052 at least 3 times, and use the highest melting and casting current as the electroslag melting and casting current for the next current change;

[0088] S1054, the electroslag casting current decreases uniformly to 0A.

[0089] In the near-net-shape forming method of impact rollers, the purpose of feeding is similar to that of casting risers, mainly to compensate for the volume shrinkage of the molten metal pool in the later stage and avoid radial shrinkage porosity of the casting. By reducing the melting rate of the consumable electrode, and thus reducing the melting speed, the purpose of feeding while melting is achieved is realized.

[0090] The inner lining of the electroslag casting crystallizer 2 is copper, and the outer shell of the electroslag casting crystallizer 2 is carbon steel plate. A cooling cavity is formed between the inner lining and the outer shell. The cooling cavity is separated into cooling channels by partitions, and the partitions are made of aluminum alloy plates.

[0091] The copper lining has good thermal conductivity, which can enhance the cooling effect on the casting.

[0092] The high hardness of carbon steel plates provides excellent support and enhances the outer shell strength of the electroslag casting crystallizer 2.

[0093] In some embodiments of this application, the thickness of the liner is 8-18 mm, the thickness of the partition is 5-15 mm, and the thickness of the cooling cavity is 20-50 mm.

[0094] S104 includes:

[0095] S1041, Stress annealing;

[0096] S1042, Normalizing;

[0097] S1043, two tempering processes.

[0098] The parameters for stress annealing, normalizing, and tempering are determined by the type of casting material, the size of the casting, and the mechanical property requirements, and are not specifically limited here.

[0099] The electroslag casting crystallizer 2 disclosed in this application has a split structure, and the outer side of each split structure is a flat plate structure. The split structures are combined to form the cavity of the electroslag casting crystallizer 2.

[0100] Based on the above description, the five electrode channels are respectively located on the two sides of the water bucket, the water divider, and the back reinforcing rib. Here, the electrode channel located on the water divider is named the first electrode channel, the electrode channel located on the two back reinforcing ribs is named the second electrode channel, and the electrode channel located on the two sides is named the third electrode channel.

[0101] During the near-net-shape forming of the half-bucket, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels. The three consumable electrodes 3 simultaneously initiate arc slag formation, forming a stable slag pool in the cross-section of the electroslag casting crystallizer 2. As the molten pool rises to the maximum cross-sectional area of ​​the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels. The five consumable electrodes 3 simultaneously perform electroslag casting, and the molten metal generated by the consumable electrodes 3 flows and forms in the overflow channel of the electroslag casting crystallizer 2.

[0102] During near-net-shape forming of the entire hopper, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels. The three consumable electrodes 3 simultaneously initiate arc slag formation, forming a stable slag pool in the cross-section of the electroslag casting crystallizer 2. As the molten pool rises to the maximum cross-sectional area of ​​the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels. The five consumable electrodes 3 simultaneously perform electroslag casting, and the molten metal generated by the consumable electrodes 3 flows and forms in the overflow channel of the electroslag casting crystallizer 2. When the molten pool rises to the 1 / 2 position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are consumed. At this time, electroslag casting is only performed through the consumable electrodes 3 located in the first electrode channel and the two second electrode channels.

[0103] During the near-net-shape forming of the bucket and spokes, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels. The three consumable electrodes 3 simultaneously initiate arc slag formation, forming a stable slag pool in the cross-section of the electroslag casting crystallizer 2. As the molten pool rises to the maximum cross-sectional area of ​​the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels. The five consumable electrodes 3 simultaneously perform electroslag casting, and the molten metal generated by the consumable electrodes 3 flows and forms in the overflow channel of the electroslag casting crystallizer 2. When the molten pool rises to the 1 / 2 position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are consumed. At this time, electroslag casting is carried out only through the consumable electrodes 3 located in the first electrode channel and the two second electrode channels. When the molten pool rises to the position of the spoke crystallizer of the electroslag casting crystallizer 2, electroslag casting is carried out only through the consumable electrodes 3 in the first electrode channel.

[0104] The near-net-shape forming method of the impact wheel disclosed in this application is used to prepare castings with irregular structures. The near-net-shape forming blank of the casting can meet the precision machining size requirements of the casting with only a little machining, the machining allowance is small, materials are saved, and the processing cycle is shortened.

[0105] By controlling the melting rate of the consumable electrode 3, the molten pool is filled with the mold cavity, so that the casting is free from defects such as porosity and gas holes. Macroscopic non-destructive testing can achieve the technical effect of forging. The microstructure is dense, the dendrites are refined, and the inclusions are dispersed. The conventional mechanical properties are comparable to forgings of the same size and are superior to large-scale integral forgings.

[0106] The castings manufactured by the near-net-shape forming method disclosed in this application have a manufacturing cycle and cost that are far lower than those of integral forging, and a quality that is far higher than that of integral casting.

[0107] Electroslag casting near-net-shape forming integrates melting, refining, solidification, and near-net-shape forming, and has the characteristics of removing non-metallic inclusions, reducing the content of harmful elements, controlling the crystallization direction, and enabling the casting to solidify sequentially.

[0108] The electroslag casting crystallizer 2 is a metal mold crystallizer. It uses a metal mold to replace a large number of non-metallic molding materials such as sand molds, binders and coatings, thereby reducing solid waste emissions, reducing environmental pollution, and realizing green manufacturing.

[0109] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed, and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. The scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A near-net-shaping method of an impact runner, characterized by, include: S101. Design the electroslag casting crystallizer (2) according to the shape and size of the water bucket unit (1), and determine the number of electrode channels of the electroslag casting crystallizer (2) according to the width of the water bucket unit (1) and the thickness of the overflow channel of the electroslag casting crystallizer (2), and manufacture the electroslag casting crystallizer (2). Wherein, the water bucket unit (1) is a unit formed by dividing the impact wheel along the plane where the opening end of the water bucket is located. The water bucket unit (1) can be 1 / 2 water bucket, 3 / 4 water bucket, the whole water bucket, the whole water bucket + part of the spokes, or the whole water bucket + spokes corresponding to the position of the whole water bucket. S102. Prepare a consumable electrode according to the size of the electrode channel (3). S103. Multiple consumable electrodes (3) are simultaneously subjected to electroslag casting. During the electroslag casting process, the consumable electrodes (3) are inserted into the electrode channels at corresponding positions in stages according to different stages. Different stages refer to the molten pool reaching different height regions during the electroslag casting process. The change in the cross-sectional area of ​​the electroslag casting crystallizer channel in different height regions leads to a change in the number of electrodes to be inserted. The molten metal formed by electroslag casting overflows and forms in the overflow channel of the electroslag casting crystallizer (2) to obtain a preform. S104. Heat-treat the preform to obtain the water bucket unit (1). It also includes S105, located between S103 and S104, for shrinkage compensation; Specifically, S105 is: S1051. The electroslag casting current is reduced at a constant rate to the minimum feeding current, and the minimum feeding current is maintained for a first preset time. S1052, the minimum feeding current is uniformly increased to the maximum casting current, and the maximum casting current is maintained for a second preset time, wherein the maximum casting current is 60%-80% of the electroslag casting current; S1053, Repeat S1051-S1052 at least 3 times, and use the highest melting and casting current as the electroslag melting and casting current for the next current change; S1054, the electroslag casting current is reduced to 0A at a constant rate.

2. The near-net-shaping method of an impact runner according to claim 1, wherein, S103 includes: S1031. A mixture of steel scrap and slag is laid at the bottom of the electroslag casting crystallizer (2); S1032. A portion of the multiple consumable electrodes (3) simultaneously arc and slag, resulting in a stable slag pool filling the cross-section of the electroslag casting crystallizer (2). S1033. Multiple consumable electrodes (3) are simultaneously subjected to electroslag casting. The molten metal formed by electroslag casting overflows and forms in the overflow channel of the electroslag casting crystallizer (2) to obtain the preform.

3. The near-net-shape forming method for the impact wheel according to claim 2, characterized in that, The slag material is a pentagonal slag, which includes CaF2, Al2O3, CaO, MgO and SiO2. The mass percentage of CaF2 is 10%-30%, the mass percentage of Al2O3 is 25%-35%, the mass percentage of CaO is 20%-30%, the mass percentage of MgO is 4%-8%, and the mass percentage of SiO2 is 2%-10%.

4. The near-net-shape forming method for the impact wheel according to claim 1, characterized in that, In S103, the filling ratio of the plurality of consumable electrodes (3) is 0.2-0.

45.

5. The near-net-shape forming method for the impact wheel according to claim 1, characterized in that, In S103, the furnace mouth voltage of the electroslag casting is 70-90V and the current is 2000-40000A.

6. The near-net-shape forming method for the impact wheel according to claim 1, characterized in that, The inner lining of the electroslag casting crystallizer (2) is a copper lining, and the outer shell of the electroslag casting crystallizer (2) is a carbon steel plate outer shell. A cooling cavity is formed between the inner lining and the outer shell. The cooling cavity is separated into cooling channels by a partition plate, and the partition plate is an aluminum alloy plate.

7. The near-net-shape forming method for the impact wheel according to claim 1, characterized in that, S104 includes: S1041, Stress annealing; S1042, Normalizing; S1043, two tempering processes.

8. The near-net-shape forming method for the impact wheel according to claim 1, characterized in that, The consumable electrode (3) is made of AOD refined steel liquid; and / or, The consumable electrode (3) is manufactured by rolling, metal mold solidification forming or steel plate welding.

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