CA3218735A1 - Near-net shape forming method for impulse wheel - Google Patents
Near-net shape forming method for impulse wheel Download PDFInfo
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- CA3218735A1 CA3218735A1 CA3218735A CA3218735A CA3218735A1 CA 3218735 A1 CA3218735 A1 CA 3218735A1 CA 3218735 A CA3218735 A CA 3218735A CA 3218735 A CA3218735 A CA 3218735A CA 3218735 A1 CA3218735 A1 CA 3218735A1
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- consumable electrodes
- bucket
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- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000005266 casting Methods 0.000 claims abstract description 166
- 239000002893 slag Substances 0.000 claims abstract description 39
- 238000002844 melting Methods 0.000 claims abstract description 18
- 230000008018 melting Effects 0.000 claims abstract description 18
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 239000002184 metal Substances 0.000 claims abstract description 15
- 238000001816 cooling Methods 0.000 claims description 11
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 11
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 10
- 239000010959 steel Substances 0.000 claims description 10
- 229910052681 coesite Inorganic materials 0.000 claims description 7
- 229910052906 cristobalite Inorganic materials 0.000 claims description 7
- 125000006850 spacer group Chemical group 0.000 claims description 7
- 229910052682 stishovite Inorganic materials 0.000 claims description 7
- 229910052905 tridymite Inorganic materials 0.000 claims description 7
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims description 6
- 229910001634 calcium fluoride Inorganic materials 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 238000000137 annealing Methods 0.000 claims description 4
- 239000010962 carbon steel Substances 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 238000005496 tempering Methods 0.000 claims description 4
- 229910000838 Al alloy Inorganic materials 0.000 claims description 3
- 238000000926 separation method Methods 0.000 claims description 3
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- 235000012239 silicon dioxide Nutrition 0.000 claims description 3
- 238000007711 solidification Methods 0.000 claims description 3
- 230000008023 solidification Effects 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 2
- 238000005096 rolling process Methods 0.000 claims description 2
- 238000003466 welding Methods 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 abstract description 5
- 239000000463 material Substances 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
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- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
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Abstract
A near-net shape forming method for an impulse wheel is provided according to an embodiment of the present application. Overflow forming of a casting such as a bucket unit is performed in a variable curved surface channel of an electroslag casting crystallizer by simultaneous melting of multiple electrodes. Consumable electrodes are inserted into electrode channels of the electroslag casting crystallizer. Positions of the electrode channels into which the consumable electrodes are inserted are determined based on a cross-sectional position of the electroslag casting crystallizer, and the number of the electrode channels into which the consumable electrodes are inserted is determined based on a cross-sectional area of the electroslag casting crystallizer. The number of the electrode channels is more than one, and the electrode channels are separately distributed along the cross-section of the electroslag casting crystallizer. Multiple consumable electrodes synchronously perform electroslag casting, and a molten metal formed by melting of the multiple consumable electrodes passes through a slag pool and enters into a molten pool. The molten pool is filled into the cross-section of an overflow channel of the electroslag casting crystallizer and simultaneously rises, to achieve forming of an irregularly-shaped casting, which eliminates the limitations that the electroslag casting can only be used to form a simple casting in the conventional techno logy.
Description
NEAR-NET SHAPE FORMING METHOD FOR IMPULSE WHEEL
FIELD
[0001] The present application relates to a technical field of thermal processing of materials, and in particular to a near-net shape forming method for an impulse wheel.
BACKGROUND
FIELD
[0001] The present application relates to a technical field of thermal processing of materials, and in particular to a near-net shape forming method for an impulse wheel.
BACKGROUND
[0002] In the conventional technology, electroslag casting can be used for forming a casting with a simple structure, such as an ingot, and is unable to be used for forming an irregularly-shaped member.
SUMMARY
SUMMARY
[0003] A near-net shape forming method for an impulse wheel is provided according to the present application, to achieve forming of an irregularly-shaped member.
[0004] In order to achieve the above object, a near-net shape forming method for an impulse wheel is provided according to the present application. The method includes:
[0005] S101, designing an electroslag casting crystallizer based on a shape and dimensions of a bucket unit, determining the number of electrode channels of the electroslag casting crystallizer based on a width of the bucket unit and a thickness of an overflow channel of the electroslag casting crystallizer, and manufacturing the electroslag casting crystallizer;
[0006] where the bucket unit is a unit formed by division of the impulse wheel along a plane where an open end of a bucket is located, and the bucket unit is one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position;
[0007] S102, preparing consumable electrodes based on dimensions of the electrode channels;
[0008] S103, simultaneously performing electroslag casting of multiple consumable electrodes, so that a molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer to be formed, to obtain a prefabricated Date Recue/Date Received 2023-11-03 member; and
[0009] S104, heat treating the prefabricated member to obtain the bucket unit.
[0010] In an embodiment, in the near-net shape forming method for an impulse wheel, S103 includes:
[0011] S1031, laying a mixture of steel chips and slag at a bottom of the electroslag casting crystallizer;
[0012] S1032, simultaneously arcing and melting slag of part of the multiple consumable electrodes to obtain a stable slag pool filled into a cross-section of the electroslag casting crystallizer;
[0013] S1033, synchronously performing electroslag casting of the multiple consumable electrodes, so that the molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer to be formed, to obtain the prefabricated member.
[0014] In an embodiment, in the near-net shape forming method for an impulse wheel, the slag is a five-component slag comprising CaF2, Al2O3, CaO, MgO and 5i02, wherein the CaF2 has a mass percentage of 10% to 30%, the Al2O3 has a mass percentage of 25% to 35%, the CaO has a mass percentage of 20% to 30%, the MgO has a mass percentage of 4%
to 8%, and the 5i02 has a mass percentage of 2% to 10%.
to 8%, and the 5i02 has a mass percentage of 2% to 10%.
[0015] In an embodiment, in the near-net shape forming method for an impulse wheel, in S103, a filling ratio of the multiple consumable electrodes ranges from 0.2 to 0.45.
[0016] In an embodiment, in the near-net shape forming method for an impulse wheel, in S103, the electroslag casting is performed at a furnace mouth voltage of 70V
to 90V and a current of 2000A to 40000A.
to 90V and a current of 2000A to 40000A.
[0017] In an embodiment, in the near-net shape forming method for an impulse wheel, between S103 and S104, the method further includes S105, feeding.
[0018] In an embodiment, in the near-net shape forming method for an impulse wheel, S105 is specifically:
[0019] S1051, uniformly reducing an electroslag casting current to a minimum feeding current and maintaining the minimum feeding current for a first predetermined time period;
Date Recue/Date Received 2023-11-03
Date Recue/Date Received 2023-11-03
[0020] S1052, uniformly increasing the minimum feeding current to a maximum casting current and maintaining the maximum casting current for a second predetermined time period, wherein the maximum casting current is equal to 60% to 80% of the electroslag casting current;
[0021] S1053, repeating S1051 to S1052 at least 3 times, and using the maximum casting current as an electroslag casting current for a next current change; and
[0022] S1054, uniformly reducing the electroslag casting current to OA.
[0023] In an embodiment, in the near-net shape forming method for an impulse wheel, a liner of the electroslag casting crystallizer is a copper liner, a housing of the electroslag casting crystallizer is a carbon steel plate housing, a cooling cavity is formed between the liner and the housing, and a cooling flow channel is formed by separation of the cooling cavity by a spacer plate, where the spacer plate is an aluminum alloy plate.
[0024] In an embodiment, in the near-net shape forming method for an impulse wheel, S104 comprises:
[0025] S1041, stress annealing;
[0026] S1042, normalizing; and
[0027] S1043, tempering twice.
[0028] In an embodiment, in the near-net shape forming method for an impulse wheel, the consumable electrodes are made of AOD refined steel liquid; and/or
[0029] the consumable electrodes are made by a rolling process, a metal-type solidification and forming process, or a steel plate splicing and welding process.
[0030] In the near-net shape forming method for an impulse wheel according to the embodiments of the present application, overflow forming of a casting such as a bucket unit is performed in a variable curved surface channel of the electroslag casting crystallizer by simultaneous melting of the multiple electrodes. The consumable electrodes are inserted into the electrode channels of the electroslag casting crystallizer. Positions of the electrode channels into which the consumable electrodes are inserted are determined based on a cross-sectional position of the electroslag casting crystallizer, and the number of the electrode channels into which the consumable electrodes are inserted is determined based on a Date Recue/Date Received 2023-11-03 cross-sectional area of the electroslag casting crystallizer. The number of the electrode channels is more than one, and the electrode channels are separately distributed along the cross-section of the electroslag casting crystallizer. Multiple consumable electrodes synchronously perform electroslag casting, and the molten metal formed by melting of the multiple consumable electrodes passes through a slag pool and enters into a molten pool. The molten pool is filled into the cross-section of the overflow channel of the electroslag casting crystallizer and simultaneously rises, to achieve forming of an irregularly-shaped casting, which eliminates the limitations that the electroslag casting can only be used to form a simple casting in the conventional technology.
BRIEF DESCRIPTION OF THE DRAWINGS
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the conventional technology, the accompanying drawings to be used in the description of the embodiments or the conventional technology will be briefly described below. Apparently, the accompanying drawings in the following description illustrate only some examples or embodiments of the present application, and other accompanying drawings can be obtained by those skilled in the art based on the provided accompanying drawings without any creative efforts. The present application can be applied to other similar scenarios based on the provided accompanying drawings. Unless obvious from the linguistic context or otherwise indicated, the same reference numerals in the drawings represent the same structure or operation.
[0032] FIG. 1 is a schematic structural view of a bucket unit according to the present application in different dividing forms;
[0033] FIG. 2 is a schematic structural view of an electroslag casting crystallizer according to the present application;
[0034] FIG. 3 is a top view of the electroslag casting crystallizer according to the present application;
[0035] FIG. 4 is a schematic structural view of an inner cavity of the electroslag casting crystallizer according to the present application;
[0036] FIG. 5 is a front view of the inner cavity of the electroslag casting crystallizer Date Recue/Date Received 2023-11-03 according to the present application;
[0037] FIG. 6 is a schematic structural view of the electroslag casting crystallizer according to the present application with consumable electrodes being inserted into part of electrode channels;
[0038] FIG. 7 is a schematic structural view of the electroslag casting crystallizer according to the present application with consumable electrodes being inserted into multiple electrode channels; and
[0039] FIG. 8 is a flowchart of a near-net shape forming method for an impulse wheel according to the present application.
[0040] The reference numerals in the accompanying drawings are as follows:
[0041] 1, bucket unit, 2, electroslag casting crystallizer, and 3, consumable electrode.
DETAILED DESCRIPTION OF THE EMBODIMENTS
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0042] The present application is further described in detail below with reference to the accompanying drawings and embodiments. It is understandable that specific embodiments described herein are used to simply explain related parts of the present application, but not to limit the present application. The embodiments described below are only some embodiments rather than all the embodiments of the present application. All the other embodiments obtained by those skilled in the art based on the embodiments in the present application without any creative efforts fall into the protection scope of the present application.
[0043] It should be noted that for easy of description, the drawings merely show the related parts of the present application. In a case of no conflict, the embodiments of the present application and features in the embodiments may be combined with each other.
[0044] It should be understood that "system", "device", "unit" and/or "module"
in the present application are used for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words serve the same object, they may be replaced by other expressions.
in the present application are used for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words serve the same object, they may be replaced by other expressions.
[0045] As shown in the present application and the claims, the words "a", "an", and/or "the"
do not specifically refer to singular, but may also include plural, unless the context clearly Date Recue/Date Received 2023-11-03 indicates exceptions. Generally speaking, the terms "include" and "comprise"
only indicate that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. Methods or devices may also contain other steps or elements. An element defined by the statement "comprising (including) a...
" does not exclude the case that other identical elements exist in the process, method, product or device including the element.
do not specifically refer to singular, but may also include plural, unless the context clearly Date Recue/Date Received 2023-11-03 indicates exceptions. Generally speaking, the terms "include" and "comprise"
only indicate that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. Methods or devices may also contain other steps or elements. An element defined by the statement "comprising (including) a...
" does not exclude the case that other identical elements exist in the process, method, product or device including the element.
[0046] In the description of the embodiments of the present application, unless otherwise specified, "I" means or, for example, A/B can mean A or B. The "and/or" herein is only an association relationship that describes the associated objects, which means that there may be three kinds of relationships, for example, A and/or B may mean that there are three cases: A
alone, A and B at the same time, and B alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more.
alone, A and B at the same time, and B alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more.
[0047] The terms "first" and "second" are for purpose of description, and should not be interpreted as indicating or implying relative importance or implying the number of the indicated technical features. Therefore, the features defined by "first" and "second" may explicitly or implicitly include one or more of the features.
[0048] A flowchart is used in the present application to explain the operation performed by the system according to the embodiment of the present application. It should be understood that the preceding or subsequent operations are not necessarily performed accurately in sequence. Instead, the steps can be processed in reverse order or simultaneously. In addition, other operations can be added to these procedures, or one or more operations can be removed from these procedures.
[0049] A bucket unit 1 is an irregularly-shaped member with non-equal-thickness three-dimensional variable curved surface. Electroslag casting of a bucket blank is performed by a crystallizer in the form of integral or block combination structures, resulting in a large post-processing allowance and a low material utilization rate.
[0050] Referring to FIG. 1 to FIG. 8, a near-net shape forming method for an impulse wheel is disclosed according to some embodiments of the present application. The method can achieve casting forming of an irregularly-shaped part.
[0051] The present application is illustrated by an example of near-net shape forming of a Date Recue/Date Received 2023-11-03 bucket unit 1 of an impulse wheel. The bucket unit 1 is a bucket structure needed by a manufacturer. As shown in FIG. 1, the bucket unit 1 may be one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and a part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position. The spoke plate may be provided with a structure such as a positioning pin or a positioning groove.
[0052] In a near-net shape forming method for an impulse wheel according to the present application, overflow forming of a casting such as a bucket unit 1 is performed in a variable curved surface channel of an electroslag casting crystallizer 2 by simultaneous melting of multiple electrodes.
.. [0053] The near-net shape forming method for an impulse wheel according to the present application comprises:
[0054] S101, designing an electroslag casting crystallizer 2 based on a shape and dimensions of a bucket unit 1, determining the number of electrode channels of the electroslag casting crystallizer 2 based on a width of the bucket unit 1 and a thickness of an overflow channel of the electroslag casting crystallizer 2, and manufacturing the electroslag casting crystallizer 2;
[0055] S102, preparing consumable electrodes 3 based on dimensions of the electrode channels;
[0056] S103, simultaneously performing electroslag casting of multiple consumable electrodes 3, so that overflow forming is performed in the overflow channel of the electroslag casting crystallizer 2, to obtain a prefabricated member; and [0057] S104, heat treating the prefabricated member to obtain the bucket unit 1.
[0058] The bucket unit 1 is a unit formed by division of the impulse wheel along a plane where an open end of a bucket is located, and the bucket unit 1 is one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position.
[0059] In the near-net shape forming method for an impulse wheel according to the present application, the consumable electrodes 3 are inserted into the electrode channels of the electroslag casting crystallizer 2. Positions of the electrode channels into which the consumable electrodes 3 are inserted are determined based on a cross-sectional position of the Date Recue/Date Received 2023-11-03 electroslag casting crystallizer 2, and the number of the electrode channels into which the consumable electrodes 3 are inserted is determined based on a cross-sectional area of the electroslag casting crystallizer 2. Taking the near-net-shape formed bucket unit 1 as an example, as shown in FIG. 2, the electroslag casting crystallizer 2 is provided with five electrode channels, which are provided at two side edges, a dividing edge, and back reinforcing bars of the bucket, respectively. Referring to FIGS. 6 and 7, a lower part of the bucket unit 1 is formed firstly, and the lower structure is located in the middle of the electroslag casting crystallizer 2. In this case, it is required to first insert three consumable electrodes 3 into the three electrode channels corresponding to the dividing edge and the back reinforcing bars. As the molten pool rises, it is required to form the middle and lower parts of the bucket unit 1. In this case, it is required to insert two consumable electrodes 3 into the electrode channels corresponding to the two side edges of the bucket.
[0060] Due to the limitation of the shape and dimensions of the overflow channel of the electroslag casting crystallizer 2, the consumable electrodes 3 cannot be inserted into the overflow channel. In the present application, the electrode channels are provided in the electroslag casting crystallizer 2, and the consumable electrodes 3 are inserted in the electrode channels.
[0061] The number of the electrode channels is multiple, and the multiple electrode channels are separately distributed along the cross-section of the electroslag casting crystallizer 2. The multiple consumable electrodes 3 synchronously perform the electroslag casting. The molten pool is filled into the cross-section of the overflow channel of the electroslag casting crystallizer 2 and simultaneously rises, to form a casting.
[0062] In the present application, multiple consumable electrodes 3 synchronously perform the electroslag casting, and the molten metal formed by melting the multiple consumable electrodes 3 passes through the slag pool and enters into the molten pool. The molten metal flows and is filled into the cross-section of the cavity of the electroslag casting transistor 2, to achieve forming of an irregularly-shaped casting.
[0063] In some embodiments of the present application, S103 includes:
[0064] S1031, laying a mixture of steel chips and slag at a bottom of the electroslag casting crystallizer 2;
Date Recue/Date Received 2023-11-03 [0065] S1032, simultaneously arcing and melting slag of part of the multiple consumable electrodes 3 to obtain a stable slag pool filled into a cross-section of the electroslag casting crystallizer 2;
[0066] S1033, synchronously performing electroslag casting of the multiple consumable electrodes 3, so that the molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer 2 to be formed, to obtain the prefabricated member.
[0067] In S1031, the mass ratio of the steel chips to the slag is equal to 3:1, and the mass ratio of the steel chips to the slag is not limited to 3:1, which may be appropriately adjusted according to components of the slag.
[0068] The mixture of the steel chips and the slag is uniformly laid at a bottom of the electroslag casting crystallizer 2, with a thickness of 20mm to 50 mm, to ensure that the multiple consumable electrodes 3 can arc synchronously.
[0069] S1032 is performed to foini, in the electroslag casting crystallizer 2, a stable slag pool filled into the entire cross-section of the electroslag casting crystallizer 2, to provide protection for the molten pool. In some embodiments of the present application, the filling ratio of the consumable electrodes 3 in S1032 is equal to 0.24.
[0070] After the stable slag pool is formed, the method proceeds to step S1033.
[0071] In S1033, the multiple consumable electrodes 3 synchronously perform the electroslag casting, and overflow forming is performed in the overflow channel. In some embodiments of the present application, the filling ratio of the consumable electrodes 3 in S1033 is equal to 0.31.
[0072] In some embodiments of the present application, the filling ratio of the multiple consumable electrodes 3 ranges from 0.2 to 0.45, to ensure that the molten metal formed in the process of melting and rising of the multiple consumable electrodes 3 is able to flow to be filled into the cross-section of the cavity of the electroslag casting crystallizer 2, to improve the quality of the electroslag casting.
[0073] The filling ratio is a ratio of a sum of the cross-sectional areas of the consumable electrodes 3 arranged in the electroslag casting crystallizer 2 to the cross-sectional area of the electroslag casting crystallizer 2.
Date Recue/Date Received 2023-11-03 [0074] In the near-net shape forming method for an impulse wheel according to the present application, the slag is a five-component slag comprising CaF2, Al2O3, CaO, MgO and SiO2.
The CaF2 has a mass percentage of 10% to 30%, the Al2O3 has a mass percentage of 25% to 35%, the CaO has a mass percentage of 20% to 30%, the MgO has a mass percentage of 4%
to 8%, and the SiO2 has a mass percentage of 2% to 10%.
[0075] The slag according to the present application has a low melting point, high electrical resistance and is weakly acidic, which can improve the forming quality and electrical efficiency and is favorable to the plastic toughness of the material compared to the two-component slag CaF2-A1203.
[0076] In the present application, the five-component slag is used as an arc initiator, rather than conventional TiO2 arc initiator, avoiding contamination of the slag system.
[0077] In an embodiment, addition amount of slag is not higher than 15% of the total mass of the slag system, and thickness of a slag layer is equal to 40% to 60% of the equivalent diameter of the electroslag casting crystallizer 2.
[0078] In S103, the electroslag casting is performed at a furnace mouth voltage of 70V to 90V and a current of 2000A to 40000A.
[0079] In the near-net shape forming method for an impulse wheel according to the present application, the furnace mouth voltage is higher than the conventional voltage by about 40%, and the use of an ultra-high voltage allows the molten pool to be moved upward, the current to be reduced while the power remains unchanged, and the depth of the consumable electrodes 3 inserted into the slag pool to become less. The slag pool functions as a heat source for melting the electrodes, the melting speed of the consumable electrodes 3 slows down, so that the molten pool has sufficient time to flow in the overflow channel, to ensure that the molten metal can overflow to be filled into the cross-section of the electroslag casting crystallizer 2, to ensure the quality of the filling.
[0080] The cm-rent gradually increased from 2000A at the arc end to 20000A at the maximum cross-sectional area of the bucket in a vertical casting direction (A-A position in FIG. 5), to control a current growth speed in a current fluctuation value of 2000 in the casting process.
[0081] After the casting exceeds the maximum cross-sectional area, it is required to reduce Date Recite/Date Received 2023-11-03 the current.
[0082] In the process, only the current is changed and the voltage is not changed, to ensure that the electroslag casting process is always performed in an ultra-high voltage.
[0083] The near-net shape forming method for an impulse wheel further includes S105, feeding, between S103 and S104.
[0084] S105 comprises the following steps S1051 to S1054.
[0085] S1051, uniformly reducing an electroslag casting current to a minimum feeding current and maintaining the minimum feeding current for a first predetermined time period;
[0086] S1052, uniformly increasing the minimum feeding current to a maximum casting current and maintaining the maximum casting current for a second predetermined time period, wherein the maximum casting current is equal to 60% to 80% of the electroslag casting current;
[0087] S1053, repeating S1051 to S1052 at least 3 times, and using the maximum casting current as an electroslag casting current for a next current change; and [0088] S1054, uniformly reducing the electroslag casting current to OA.
[0089] The function of the feeding in the near-net shape forming method for an impulse wheel is similar to the function of casting a riser, which is mainly to compensate for the volume shrinkage of the metal molten pool at a later stage and to avoid radial shrinkage of the casting. By reducing the melting speed of the consumable electrodes and in turn reducing the melting velocity, the purpose of feeding while melting is achieved.
[0090] A liner of the electroslag casting crystallizer 2 is a copper liner, a housing of the electroslag casting crystallizer 2 is a carbon steel plate housing, a cooling cavity is formed between the liner and the housing, and a cooling flow channel is formed by separation of the cooling cavity by a spacer plate. The spacer plate is an aluminum alloy plate.
[0091] The copper liner has good thermal conductivity and can enhance the cooling effect on the casting.
[0092] The carbon steel plate has high hardness and can provide firm support to improve the strength of the housing of the electroslag casting crystallizer 2.
[0093] In some embodiments of the present application, the liner has a thickness ranging Date Recue/Date Received 2023-11-03 from 8mm to 18 mm, the spacer plate has a thickness ranging from 5mm to 15 mm, and the cooling cavity has a thickness ranging from 20mm to 50 mm.
[0094] S104 comprises the following steps S1041 to S1043.
[0095] S1041, stress annealing;
[0096] S1042, normalizing; and [0097] S1043, tempering twice.
[0098] Parameters of the stress annealing, the normalizing, and the tempering are determined by the type of material of the casting, the dimensions of the casting, and the mechanical property requirements of the casting, and are not specifically limited herein.
[0099] The electroslag casting crystallizer 2 according to the present application is configured as split structures, and an outer side of each of the split structures is of a flat plate structure, and the combination of the split structures constitutes the cavity of the electroslag casting crystallizer 2.
[0100] In conjunction with the above description, five electrode channels are respectively provided at two side edges, a dividing edge, and back reinforcing bars of the bucket, respectively. The electrode channel located at the dividing edge is named as a first electrode channel, the electrode channels located at the two back reinforcing bars are named as second electrode channels, and the electrode channels located at the two side edges are named as third electrode channels.
[0101] During the near-net shape forming of one half of the bucket, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2.
[0102] During the near-net shape forming of the entire bucket, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three Date Recue/Date Received 2023-11-03 consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2. As the molten pool rises to the one half position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are completely consumed, and at this time, the electroslag casting of the consumable electrodes 3 located only in the first electrode channel and the two second electrode channels is performed.
[0103] During the near-net shape forming of the entire bucket and the spoke plate, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2. As the molten pool rises to the one half position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are completely consumed, and at this time, the electroslag casting of the consumable electrodes 3 located only in the first electrode channel and the two second electrode channels is performed. As the molten pool rises to a position of a spoke plate crystallizer of the electroslag casting crystallizer 2, the electroslag casting of the consumable electrode 3 located in only the first electrode channel is performed.
[0104] The near-net shape forming method for an impulse wheel according to the present application is used to prepare a casting with an irregularly-shaped structure.
The near-net shape formed casting blank can meet the size requirements of finishing of the casting with only a small amount of processing, in which a machining allowance is small, the materials are saved and the processing cycle is shortened.
[0105] By controlling the melting speed of the consumable electrodes 3, the molten pool is Date Recue/Date Received 2023-11-03 filled into the cavity so that the casting is free of defects such as looseness and porosity, and can reach the technical effect of forgings under the macroscopic non-destructive testing, with a dense microstructure, fine dendritic crystal, and diffusely distributed inclusions. In addition, the conventional mechanical properties are comparable to forgings of the same size level, and are better than those of large-level integrally forged parts.
[0106] The castings manufactured by the near-net shape forming method according to the present application have manufacturing cycle and costs much lower than those in a case of integral forging and the quality much higher than that in a case of integral forging.
[0107] The near-net shape forming by the electroslag casting integrates melting, refining, solidification, and near-net shape forming, and has the characteristics of removing non-metallic inclusions, reducing the content of hazardous elements, controlling the direction of crystallization, and making the casting be solidified sequentially.
[0108] The electroslag casting crystallizer 2 is a metal-type crystallizer, and the use of metal-type crystallizer to replace a large number of non-metallic molding materials such as sand, binders and paints makes the solid waste emission reduced, reduces the pollution of the environment and realizes green manufacturing.
[0109] The above description illustrates only preferable embodiments of the present application and an illustration of the technical principles applied, which are not intended to limit the present application. Various changes and variations may be made by those skilled in the art to the present application. The scope of the present application is not limited to the technical solutions formed by a particular combination of the above technical features, but also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above application concept. For example, the scope of the present application may cover a technical solution formed by replacing the features described above with technical features with similar functions disclosed in (but not limited to) the present application.
Date Recue/Date Received 2023-11-03
.. [0053] The near-net shape forming method for an impulse wheel according to the present application comprises:
[0054] S101, designing an electroslag casting crystallizer 2 based on a shape and dimensions of a bucket unit 1, determining the number of electrode channels of the electroslag casting crystallizer 2 based on a width of the bucket unit 1 and a thickness of an overflow channel of the electroslag casting crystallizer 2, and manufacturing the electroslag casting crystallizer 2;
[0055] S102, preparing consumable electrodes 3 based on dimensions of the electrode channels;
[0056] S103, simultaneously performing electroslag casting of multiple consumable electrodes 3, so that overflow forming is performed in the overflow channel of the electroslag casting crystallizer 2, to obtain a prefabricated member; and [0057] S104, heat treating the prefabricated member to obtain the bucket unit 1.
[0058] The bucket unit 1 is a unit formed by division of the impulse wheel along a plane where an open end of a bucket is located, and the bucket unit 1 is one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position.
[0059] In the near-net shape forming method for an impulse wheel according to the present application, the consumable electrodes 3 are inserted into the electrode channels of the electroslag casting crystallizer 2. Positions of the electrode channels into which the consumable electrodes 3 are inserted are determined based on a cross-sectional position of the Date Recue/Date Received 2023-11-03 electroslag casting crystallizer 2, and the number of the electrode channels into which the consumable electrodes 3 are inserted is determined based on a cross-sectional area of the electroslag casting crystallizer 2. Taking the near-net-shape formed bucket unit 1 as an example, as shown in FIG. 2, the electroslag casting crystallizer 2 is provided with five electrode channels, which are provided at two side edges, a dividing edge, and back reinforcing bars of the bucket, respectively. Referring to FIGS. 6 and 7, a lower part of the bucket unit 1 is formed firstly, and the lower structure is located in the middle of the electroslag casting crystallizer 2. In this case, it is required to first insert three consumable electrodes 3 into the three electrode channels corresponding to the dividing edge and the back reinforcing bars. As the molten pool rises, it is required to form the middle and lower parts of the bucket unit 1. In this case, it is required to insert two consumable electrodes 3 into the electrode channels corresponding to the two side edges of the bucket.
[0060] Due to the limitation of the shape and dimensions of the overflow channel of the electroslag casting crystallizer 2, the consumable electrodes 3 cannot be inserted into the overflow channel. In the present application, the electrode channels are provided in the electroslag casting crystallizer 2, and the consumable electrodes 3 are inserted in the electrode channels.
[0061] The number of the electrode channels is multiple, and the multiple electrode channels are separately distributed along the cross-section of the electroslag casting crystallizer 2. The multiple consumable electrodes 3 synchronously perform the electroslag casting. The molten pool is filled into the cross-section of the overflow channel of the electroslag casting crystallizer 2 and simultaneously rises, to form a casting.
[0062] In the present application, multiple consumable electrodes 3 synchronously perform the electroslag casting, and the molten metal formed by melting the multiple consumable electrodes 3 passes through the slag pool and enters into the molten pool. The molten metal flows and is filled into the cross-section of the cavity of the electroslag casting transistor 2, to achieve forming of an irregularly-shaped casting.
[0063] In some embodiments of the present application, S103 includes:
[0064] S1031, laying a mixture of steel chips and slag at a bottom of the electroslag casting crystallizer 2;
Date Recue/Date Received 2023-11-03 [0065] S1032, simultaneously arcing and melting slag of part of the multiple consumable electrodes 3 to obtain a stable slag pool filled into a cross-section of the electroslag casting crystallizer 2;
[0066] S1033, synchronously performing electroslag casting of the multiple consumable electrodes 3, so that the molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer 2 to be formed, to obtain the prefabricated member.
[0067] In S1031, the mass ratio of the steel chips to the slag is equal to 3:1, and the mass ratio of the steel chips to the slag is not limited to 3:1, which may be appropriately adjusted according to components of the slag.
[0068] The mixture of the steel chips and the slag is uniformly laid at a bottom of the electroslag casting crystallizer 2, with a thickness of 20mm to 50 mm, to ensure that the multiple consumable electrodes 3 can arc synchronously.
[0069] S1032 is performed to foini, in the electroslag casting crystallizer 2, a stable slag pool filled into the entire cross-section of the electroslag casting crystallizer 2, to provide protection for the molten pool. In some embodiments of the present application, the filling ratio of the consumable electrodes 3 in S1032 is equal to 0.24.
[0070] After the stable slag pool is formed, the method proceeds to step S1033.
[0071] In S1033, the multiple consumable electrodes 3 synchronously perform the electroslag casting, and overflow forming is performed in the overflow channel. In some embodiments of the present application, the filling ratio of the consumable electrodes 3 in S1033 is equal to 0.31.
[0072] In some embodiments of the present application, the filling ratio of the multiple consumable electrodes 3 ranges from 0.2 to 0.45, to ensure that the molten metal formed in the process of melting and rising of the multiple consumable electrodes 3 is able to flow to be filled into the cross-section of the cavity of the electroslag casting crystallizer 2, to improve the quality of the electroslag casting.
[0073] The filling ratio is a ratio of a sum of the cross-sectional areas of the consumable electrodes 3 arranged in the electroslag casting crystallizer 2 to the cross-sectional area of the electroslag casting crystallizer 2.
Date Recue/Date Received 2023-11-03 [0074] In the near-net shape forming method for an impulse wheel according to the present application, the slag is a five-component slag comprising CaF2, Al2O3, CaO, MgO and SiO2.
The CaF2 has a mass percentage of 10% to 30%, the Al2O3 has a mass percentage of 25% to 35%, the CaO has a mass percentage of 20% to 30%, the MgO has a mass percentage of 4%
to 8%, and the SiO2 has a mass percentage of 2% to 10%.
[0075] The slag according to the present application has a low melting point, high electrical resistance and is weakly acidic, which can improve the forming quality and electrical efficiency and is favorable to the plastic toughness of the material compared to the two-component slag CaF2-A1203.
[0076] In the present application, the five-component slag is used as an arc initiator, rather than conventional TiO2 arc initiator, avoiding contamination of the slag system.
[0077] In an embodiment, addition amount of slag is not higher than 15% of the total mass of the slag system, and thickness of a slag layer is equal to 40% to 60% of the equivalent diameter of the electroslag casting crystallizer 2.
[0078] In S103, the electroslag casting is performed at a furnace mouth voltage of 70V to 90V and a current of 2000A to 40000A.
[0079] In the near-net shape forming method for an impulse wheel according to the present application, the furnace mouth voltage is higher than the conventional voltage by about 40%, and the use of an ultra-high voltage allows the molten pool to be moved upward, the current to be reduced while the power remains unchanged, and the depth of the consumable electrodes 3 inserted into the slag pool to become less. The slag pool functions as a heat source for melting the electrodes, the melting speed of the consumable electrodes 3 slows down, so that the molten pool has sufficient time to flow in the overflow channel, to ensure that the molten metal can overflow to be filled into the cross-section of the electroslag casting crystallizer 2, to ensure the quality of the filling.
[0080] The cm-rent gradually increased from 2000A at the arc end to 20000A at the maximum cross-sectional area of the bucket in a vertical casting direction (A-A position in FIG. 5), to control a current growth speed in a current fluctuation value of 2000 in the casting process.
[0081] After the casting exceeds the maximum cross-sectional area, it is required to reduce Date Recite/Date Received 2023-11-03 the current.
[0082] In the process, only the current is changed and the voltage is not changed, to ensure that the electroslag casting process is always performed in an ultra-high voltage.
[0083] The near-net shape forming method for an impulse wheel further includes S105, feeding, between S103 and S104.
[0084] S105 comprises the following steps S1051 to S1054.
[0085] S1051, uniformly reducing an electroslag casting current to a minimum feeding current and maintaining the minimum feeding current for a first predetermined time period;
[0086] S1052, uniformly increasing the minimum feeding current to a maximum casting current and maintaining the maximum casting current for a second predetermined time period, wherein the maximum casting current is equal to 60% to 80% of the electroslag casting current;
[0087] S1053, repeating S1051 to S1052 at least 3 times, and using the maximum casting current as an electroslag casting current for a next current change; and [0088] S1054, uniformly reducing the electroslag casting current to OA.
[0089] The function of the feeding in the near-net shape forming method for an impulse wheel is similar to the function of casting a riser, which is mainly to compensate for the volume shrinkage of the metal molten pool at a later stage and to avoid radial shrinkage of the casting. By reducing the melting speed of the consumable electrodes and in turn reducing the melting velocity, the purpose of feeding while melting is achieved.
[0090] A liner of the electroslag casting crystallizer 2 is a copper liner, a housing of the electroslag casting crystallizer 2 is a carbon steel plate housing, a cooling cavity is formed between the liner and the housing, and a cooling flow channel is formed by separation of the cooling cavity by a spacer plate. The spacer plate is an aluminum alloy plate.
[0091] The copper liner has good thermal conductivity and can enhance the cooling effect on the casting.
[0092] The carbon steel plate has high hardness and can provide firm support to improve the strength of the housing of the electroslag casting crystallizer 2.
[0093] In some embodiments of the present application, the liner has a thickness ranging Date Recue/Date Received 2023-11-03 from 8mm to 18 mm, the spacer plate has a thickness ranging from 5mm to 15 mm, and the cooling cavity has a thickness ranging from 20mm to 50 mm.
[0094] S104 comprises the following steps S1041 to S1043.
[0095] S1041, stress annealing;
[0096] S1042, normalizing; and [0097] S1043, tempering twice.
[0098] Parameters of the stress annealing, the normalizing, and the tempering are determined by the type of material of the casting, the dimensions of the casting, and the mechanical property requirements of the casting, and are not specifically limited herein.
[0099] The electroslag casting crystallizer 2 according to the present application is configured as split structures, and an outer side of each of the split structures is of a flat plate structure, and the combination of the split structures constitutes the cavity of the electroslag casting crystallizer 2.
[0100] In conjunction with the above description, five electrode channels are respectively provided at two side edges, a dividing edge, and back reinforcing bars of the bucket, respectively. The electrode channel located at the dividing edge is named as a first electrode channel, the electrode channels located at the two back reinforcing bars are named as second electrode channels, and the electrode channels located at the two side edges are named as third electrode channels.
[0101] During the near-net shape forming of one half of the bucket, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2.
[0102] During the near-net shape forming of the entire bucket, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three Date Recue/Date Received 2023-11-03 consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2. As the molten pool rises to the one half position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are completely consumed, and at this time, the electroslag casting of the consumable electrodes 3 located only in the first electrode channel and the two second electrode channels is performed.
[0103] During the near-net shape forming of the entire bucket and the spoke plate, consumable electrodes 3 are inserted into the first electrode channel and the two second electrode channels, and the three consumable electrodes 3 synchronously arc and melt slag to form a stable slag pool in the cross-section of the electroslag casting crystallizer 2. With the molten pool rising to the maximum cross-sectional area of the electroslag casting crystallizer 2, consumable electrodes 3 are inserted into the two third electrode channels, and the five consumable electrodes 3 simultaneously perform electroslag casting. The molten metal formed by the consumable electrodes 3 flows and is formed in the overflow channel of the electroslag casting crystallizer 2. As the molten pool rises to the one half position of the electroslag casting crystallizer 2, the consumable electrodes 3 located in the two third electrode channels are completely consumed, and at this time, the electroslag casting of the consumable electrodes 3 located only in the first electrode channel and the two second electrode channels is performed. As the molten pool rises to a position of a spoke plate crystallizer of the electroslag casting crystallizer 2, the electroslag casting of the consumable electrode 3 located in only the first electrode channel is performed.
[0104] The near-net shape forming method for an impulse wheel according to the present application is used to prepare a casting with an irregularly-shaped structure.
The near-net shape formed casting blank can meet the size requirements of finishing of the casting with only a small amount of processing, in which a machining allowance is small, the materials are saved and the processing cycle is shortened.
[0105] By controlling the melting speed of the consumable electrodes 3, the molten pool is Date Recue/Date Received 2023-11-03 filled into the cavity so that the casting is free of defects such as looseness and porosity, and can reach the technical effect of forgings under the macroscopic non-destructive testing, with a dense microstructure, fine dendritic crystal, and diffusely distributed inclusions. In addition, the conventional mechanical properties are comparable to forgings of the same size level, and are better than those of large-level integrally forged parts.
[0106] The castings manufactured by the near-net shape forming method according to the present application have manufacturing cycle and costs much lower than those in a case of integral forging and the quality much higher than that in a case of integral forging.
[0107] The near-net shape forming by the electroslag casting integrates melting, refining, solidification, and near-net shape forming, and has the characteristics of removing non-metallic inclusions, reducing the content of hazardous elements, controlling the direction of crystallization, and making the casting be solidified sequentially.
[0108] The electroslag casting crystallizer 2 is a metal-type crystallizer, and the use of metal-type crystallizer to replace a large number of non-metallic molding materials such as sand, binders and paints makes the solid waste emission reduced, reduces the pollution of the environment and realizes green manufacturing.
[0109] The above description illustrates only preferable embodiments of the present application and an illustration of the technical principles applied, which are not intended to limit the present application. Various changes and variations may be made by those skilled in the art to the present application. The scope of the present application is not limited to the technical solutions formed by a particular combination of the above technical features, but also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above application concept. For example, the scope of the present application may cover a technical solution formed by replacing the features described above with technical features with similar functions disclosed in (but not limited to) the present application.
Date Recue/Date Received 2023-11-03
Claims (10)
1. A near-net shape forming method for an impulse wheel, comprising:
S101, designing an electroslag casting crystallizer (2) based on a shape and dimensions of a bucket unit (1), determining the number of electrode channels of the electroslag casting crystallizer (2) based on a width of the bucket unit (1) and a thickness of an overflow channel of the electroslag casting crystallizer (2), and manufacturing the electroslag casting crystallizer (2);
wherein the bucket unit (1) is a unit formed by division of the impulse wheel along a plane where an open end of a bucket is located, and the bucket unit (1) is one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position;
S102, preparing consumable electrodes (3) based on dimensions of the electrode channels;
S103, simultaneously performing electroslag casting of multiple consumable electrodes (3), so that a molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer (2) to be formed, to obtain a prefabricated member; and S104, heat treating the prefabricated member to obtain the bucket unit (1).
S101, designing an electroslag casting crystallizer (2) based on a shape and dimensions of a bucket unit (1), determining the number of electrode channels of the electroslag casting crystallizer (2) based on a width of the bucket unit (1) and a thickness of an overflow channel of the electroslag casting crystallizer (2), and manufacturing the electroslag casting crystallizer (2);
wherein the bucket unit (1) is a unit formed by division of the impulse wheel along a plane where an open end of a bucket is located, and the bucket unit (1) is one half of a bucket, three fourths of a bucket, an entire bucket, an entire bucket and part of a spoke plate, or an entire bucket and an entire spoke plate corresponding to the entire bucket in position;
S102, preparing consumable electrodes (3) based on dimensions of the electrode channels;
S103, simultaneously performing electroslag casting of multiple consumable electrodes (3), so that a molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer (2) to be formed, to obtain a prefabricated member; and S104, heat treating the prefabricated member to obtain the bucket unit (1).
2. The near-net shape forming method for an impulse wheel according to claim 1, wherein S103 comprises:
S1031, laying a mixture of steel chips and slag at a bottom of the electroslag casting crystallizer (2);
S1032, simultaneously arc starting and melting slag of part of the multiple consumable electrodes (3) to obtain a stable slag pool filled into a cross-section of the electroslag casting crystallizer (2);
S1033, synchronously performing electroslag casting of the multiple consumable electrodes (3), so that the molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer (2) to be formed, to obtain the prefabricated member.
S1031, laying a mixture of steel chips and slag at a bottom of the electroslag casting crystallizer (2);
S1032, simultaneously arc starting and melting slag of part of the multiple consumable electrodes (3) to obtain a stable slag pool filled into a cross-section of the electroslag casting crystallizer (2);
S1033, synchronously performing electroslag casting of the multiple consumable electrodes (3), so that the molten metal formed by the electroslag casting overflows into the overflow channel of the electroslag casting crystallizer (2) to be formed, to obtain the prefabricated member.
3. The near-net shape forming method for an impulse wheel according to claim 2, wherein the slag is a five-component slag comprising CaF2, A1203, CaO, Mg0 and Si02, wherein the CaF2 has a mass percentage of 10% to 30%, the A1203 has a mass percentage of 25% to 35%, the Ca0 has a mass percentage of 20% to 30%, the Mg0 has a mass percentage of 4% to 8%, and the SiO2 has a mass percentage of 2% to 10%.
4. The near-net shape forming method for an impulse wheel according to claim 1, wherein in S103, a filling ratio of the multiple consumable electrodes (3) ranges from 0.2 to 0.45.
5. The near-net shape forming method for an impulse wheel according to claim 1, wherein in S103, the electroslag casting is performed at a furnace mouth voltage of 70V to 90V and a current of 2000A to 40000A.
6. The near-net shape forming method for an impulse wheel according to claim 1, wherein, between S103 and S104, the method further comprises S105, feeding.
7. The near-net shape forming method for an impulse wheel according to claim 6, wherein S105 is:
S1051, uniformly reducing an electroslag casting current to a minimum feeding current and maintaining the minimum feeding current for a first predetermined time period;
S1052, uniformly increasing the minimum feeding current to a maximum casting current and maintaining the maximum casting current for a second predetermined time period, wherein the maximum casting current is equal to 60% to 80% of the electroslag casting current;
S1053, repeating S1051 to S1052 at least 3 times, and using the maximum casting current as an electroslag casting current for a next current change; and S1054, uniformly reducing the electroslag casting current to OA.
S1051, uniformly reducing an electroslag casting current to a minimum feeding current and maintaining the minimum feeding current for a first predetermined time period;
S1052, uniformly increasing the minimum feeding current to a maximum casting current and maintaining the maximum casting current for a second predetermined time period, wherein the maximum casting current is equal to 60% to 80% of the electroslag casting current;
S1053, repeating S1051 to S1052 at least 3 times, and using the maximum casting current as an electroslag casting current for a next current change; and S1054, uniformly reducing the electroslag casting current to OA.
8. The near-net shape forming method for an impulse wheel according to claim 1, wherein a liner of the electroslag casting crystallizer (2) is a copper liner, a housing of the electroslag casting crystallizer (2) is a carbon steel plate housing, a cooling cavity is formed between the liner and the housing, and a cooling flow channel is formed by separation of the cooling cavity by a spacer plate, wherein the spacer plate is an aluminum alloy plate.
9. The near-net shape forming method for an impulse wheel according to claim 1, wherein S104 comprises:
S1041, stress annealing;
S1042, normalizing ; and S1043, tempering twice.
S1041, stress annealing;
S1042, normalizing ; and S1043, tempering twice.
10. The near-net shape forming method for an impulse wheel according to claim 1, wherein the consumable electrodes (3) are made of AOD refined steel liquid;
and/or the consumable electrodes (3) are made by a rolling process, a metal-type solidification and forming process, or a steel plate splicing and welding process.
and/or the consumable electrodes (3) are made by a rolling process, a metal-type solidification and forming process, or a steel plate splicing and welding process.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211460321.0A CN115709273A (en) | 2022-11-17 | 2022-11-17 | Near-net forming method of impact runner |
| CN202211460321.0 | 2022-11-17 |
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| Publication Number | Publication Date |
|---|---|
| CA3218735A1 true CA3218735A1 (en) | 2024-05-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3218735A Pending CA3218735A1 (en) | 2022-11-17 | 2023-11-03 | Near-net shape forming method for impulse wheel |
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| Country | Link |
|---|---|
| CN (1) | CN115709273A (en) |
| CA (1) | CA3218735A1 (en) |
-
2022
- 2022-11-17 CN CN202211460321.0A patent/CN115709273A/en active Pending
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- 2023-11-03 CA CA3218735A patent/CA3218735A1/en active Pending
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