Split type nanocrystalline alloy steel pouring tank

Abstract

The utility model discloses a split type nanocrystalline alloy steel pouring groove which is formed by splicing a graphite runner groove located at the rear section and a corundum steel pouring head located at the front section, the graphite runner groove is made of graphite, the corundum steel pouring head is made of tabular corundum, and the graphite runner groove and the corundum steel pouring head are detachably connected through a lap joint structure. The detachable and replaceable split type structural design is adopted, the nanocrystalline alloy steel pouring groove is divided into two parts, the graphite runner groove and the corundum steel pouring head which are made of different materials are spliced, the two-section structure can be replaced independently, and overall replacement caused by local damage is avoided; besides, the advantages of corundum materials and graphite materials are fully utilized, cost is controlled, molten steel is prevented from adhering to the runner groove, and the defects that an existing integral type graphite nanocrystalline alloy steel pouring groove is short in service life and the molten steel is prone to adhering to the integral type corundum nanocrystalline alloy steel pouring groove are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of steel casting ladles, in particular to a split-type nanocrystalline alloy steel casting ladle for the production and preparation of nanocrystalline alloy strips. Background Technique

[0002] Due to excellent electromagnetic properties, high saturation magnetic induction intensity, high squareness ratio, high magnetic permeability, low loss, stable performance and other advantages, nanocrystalline alloy soft magnetic materials have developed rapidly in production applications in recent years, especially in various high-quality iron core materials used in switching power supplies and ISDN. At present, nanocrystalline alloy strips are mainly produced by the single-roll rapid quenching method, and its preparation process is as follows: the nanocrystalline master alloy is put into a vacuum medium-frequency furnace for remelting, and after melting, the alloy steel liquid is poured into the nozzle package through the nanocrystalline master alloy steel casting ladle and heated up. After heating up to 1400 °C, the alloy steel liquid flows out of the nozzle package, passes through the water inlet and the nozzle cup, and finally is sprayed onto the high-speed rotating cooling copper roll through the nozzle for condensation, and finally forms a nanocrystalline alloy strip with a thickness of 16 - 30 μm and a width of 10 - 75 mm. The nanocrystalline master alloy steel casting ladle is one of the key components of the nanocrystalline alloy strip production line. It is installed at the tail of the vacuum melting furnace, and its main function is to pour the nanocrystalline master alloy steel liquid of the vacuum melting furnace into the nozzle package, and it is the bridge between the vacuum melting furnace and the nozzle package.

[0003] The existing nanocrystalline master alloy steel casting ladles are integral types. According to different materials, there are mainly the following two types:

[0004] The first type is an integral corundum steel casting ladle, and all materials are plate-shaped corundum. The advantages are simple structure and low cost. However, there are the following disadvantages: ① The service life of the corundum casting head is short. Under the continuous scouring of high-temperature steel liquid, the service life is very short, and it cracks and becomes scrapped in about 1 month; ② The surface of the corundum runner groove is rough, and the steel liquid is easy to adhere to both sides of the runner groove, which is troublesome to clean; ③ After the steel liquid remaining in the runner groove cools, the steel block will firmly adhere to the bottom wall of the corundum runner groove, making it easy to dig out the bottom wall of the runner groove when removing the steel block later, resulting in pitted bottom walls, generating slag, and polluting the steel liquid.

[0005] The second type is an integral graphite steel casting ladle, and all materials are graphite. It has two advantages: ① The graphite surface is smooth, and the steel liquid is not easy to adhere to both sides of the graphite steel casting ladle; ② After the steel liquid remaining in the graphite runner groove cools, it will automatically separate from the bottom wall of the graphite runner groove and will not adhere to the bottom of the graphite groove, which is easy to clean. However, there are also two disadvantages, which are respectively: ① The graphite casting head is relatively fragile. Under the continuous scouring of high-temperature steel liquid, the service life is very short, and it cracks and becomes scrapped in one month; ② The manufacturing cost of the graphite steel casting ladle is high, which is 5 - 6 times that of the corundum steel casting ladle.

[0006] Therefore, there is an urgent need for a new type of steel casting ladle with relatively low cost, long service life and not easy to adhere steel liquid on the runner groove. Summary of the Utility Model

[0007] The purpose of the present utility model is to provide a split-type nanocrystalline alloy steel-pouring trough, which adopts a detachable and replaceable split-type structure design. The graphite runner trough and the corundum steel-pouring head, which are made of different materials respectively, are spliced to form a split-type nanocrystalline alloy steel-pouring trough. It can perfectly integrate the advantages of the two materials, making the split-type nanocrystalline alloy steel-pouring trough have the advantages of long service life, low cost and steel liquid not easily adhering to the runner trough, and well solving the disadvantages of the existing integral graphite nanocrystalline alloy steel-pouring trough with short service life and the integral corundum nanocrystalline alloy steel-pouring trough being prone to adhering steel liquid mentioned in the above background technology.

[0008] In order to achieve the above purpose, the present utility model adopts the following technical solutions:

[0009] A split-type nanocrystalline alloy steel-pouring trough is formed by splicing a graphite runner trough located at the rear section and a corundum steel-pouring head located at the front section. The graphite runner trough is made of graphite, the corundum steel-pouring head is made of plate-shaped corundum, and the graphite runner trough and the corundum steel-pouring head are detachably connected through a lapping structure.

[0010] Further, the graphite runner trough includes a horizontally distributed trough bottom. On both sides of the trough bottom and on the side away from the corundum steel-pouring head, there are trough walls extending upward. At one end of the trough bottom away from the corundum steel-pouring head, there is a blanking pipe with an opening downward; the corundum steel-pouring head includes a steel-pouring head body. The upper surface of the steel-pouring head body has a diversion arc surface distributed upward away from the graphite runner trough, and on both sides of the steel-pouring head body, there are baffle edges extending upward respectively.

[0011] Further, the central axis of the blanking pipe is vertically distributed with respect to the trough bottom, and the whole blanking pipe is in a conical shape with a larger upper part and a smaller lower part.

[0012] Preferably, the taper of the blanking pipe is (1:10) to (1:20).

[0013] Further, between the trough wall and the trough bottom and between the baffle edge and the steel-pouring head body, there are arc surface transitions.

[0014] Further, the radian of the diversion arc surface is R500mm to R1000mm.

[0015] Further, the lapping structure includes an upper lapping head and a lower lapping head that are seamlessly lapped and connected.

[0016] Further, both the upper lapping head and the lower lapping head are distributed along the width direction of the split-type nanocrystalline alloy steel-pouring trough.

[0017] Furthermore, the upper joint is arranged at one end of the corundum steel-pouring head close to the graphite runner groove, and the lower joint is arranged at one end of the graphite runner groove close to the corundum steel-pouring head.

[0018] Furthermore, the cross-sectional shapes of the upper joint and the lower joint are both rectangular.

[0019] Compared with the prior art, the present utility model provides a split-type nanocrystalline alloy steel-pouring groove, having the following beneficial effects:

[0020] The present utility model adopts a detachable and replaceable split-type structural design, splitting the nanocrystalline alloy steel-pouring groove into two parts, and splicing a graphite runner groove and a corundum steel-pouring head made of different materials. The corundum steel-pouring head at the front section and the graphite runner groove at the rear section can be independently replaced, avoiding overall replacement due to local damage.

[0021] Since the front-section steel-pouring head has a short service life and is made of inexpensive corundum material, the cost during frequent replacement can be lower; while the rear-section runner groove has a long service life and is made of relatively expensive graphite material, the cost of low-frequency replacement can be reduced. The present utility model makes full use of the advantages of corundum material and graphite material, successfully avoids the disadvantages of the two materials, achieves an optimal combination, controls the cost, and avoids molten steel from adhering to the runner groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is the front view sectional structure schematic diagram of the present utility model;

[0024] Figure 2 is the top view structure schematic diagram of the present utility model;

[0025] Figure 3 is Figure 1 the sectional view along the A-A direction in

[0026] Figure 4 is Figure 2 the sectional view along the B-B direction in

[0027] Reference numerals: 1, graphite runner groove; 11, groove bottom; 12, groove wall; 13, blanking pipe; 14, lower joint; 2, corundum steel-pouring head; 21, steel-pouring head body; 22, diversion arc surface; 23, retaining edge; 24, upper joint. Detailed implementation mode

[0028] The technical solution of the present utility model will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative work belong to the scope of protection of the present utility model.

[0029] Embodiment 1

[0030] Reference Figures 1 to 4 , the present utility model provides a split nano-crystalline alloy steel-pouring trough, which is formed by splicing a graphite runner trough 1 located in the rear section and a corundum steel-pouring head 2 located in the front section. The graphite runner trough 1 and the corundum steel-pouring head 2 are detachably connected through a lapping structure.

[0031] Among them, the graphite runner trough 1 is made of graphite. Specifically, the graphite runner trough 1 includes a horizontally distributed trough bottom 11. On both sides of the trough bottom 11 and on the side far from the corundum steel-pouring head 2, upwardly extending trough walls 12 are provided. At one end of the trough bottom 11 far from the corundum steel-pouring head, a blanking pipe 13 with a downward opening is provided. The central axis of the blanking pipe 13 is vertically distributed with respect to the trough bottom 11. The overall shape of the blanking pipe 13 is a frustum of a cone with a larger top and a smaller bottom, and the taper is (1:10) to (1:20), so as to facilitate connection with the steel-pouring port of the nozzle package. The transition between the trough wall 12 and the trough bottom 11 is an arc surface to avoid stress concentration. As an example, the purity of the graphite used to prepare the graphite runner trough is above 99%.

[0032] The corundum steel-pouring head 2 is made of plate-shaped corundum. Specifically, the corundum steel-pouring head 2 includes a steel-pouring head body 21. The upper surface of the steel-pouring head body 21 has a diversion arc surface 22 distributed upward away from the graphite runner trough 1. On both sides of the steel-pouring head body 21, upwardly extending retaining edges 23 are provided. The transition between the retaining edge 23 and the steel-pouring head body 21 is an arc surface to avoid stress concentration. The radian of the diversion arc surface 22 is R500mm to R1000mm, and the specific specification dimensions can be set according to the use requirements.

[0033] In some specific implementation modes, the lapping structure includes an upper lapping head 24 and a lower lapping head 14 that are seamlessly lapped and connected. Specifically, both the upper lapping head 24 and the lower lapping head 14 are distributed along the width direction of the split nano-crystalline alloy steel-pouring trough. As an example, in this embodiment, the upper lapping head 24 is provided at one end of the corundum steel-pouring head 2 close to the graphite runner trough 1, the lower lapping head 14 is provided at one end of the graphite runner trough 1 close to the corundum steel-pouring head 2, and the cross-sectional shapes of the upper lapping head 24 and the lower lapping head 14 are both rectangular.

[0034] Thus, by adopting the split - type structure design, the advantages of two materials are combined, and the disadvantages of the existing integral graphite nanocrystal alloy steel - pouring trough with short service life and the integral corundum nanocrystal alloy steel - pouring trough being prone to adhering molten steel are well solved.

[0035] The following further describes the present utility model in detail through specific preparation examples in conjunction with the accompanying drawings.

[0036] Unless otherwise specified, the experimental and testing methods used in the preparation examples are all conventional methods, and the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0037] Preparation Example 1

[0038] A split - type nanocrystal alloy steel - pouring trough is formed by splicing a graphite flow - channel trough 1 at the rear section and a corundum steel - pouring head 2 at the front section. The structure is as Figures 1 to 4 shown. The same as in Embodiment 1, so it will not be described in detail again. Its specific preparation method is as follows:

[0039] S1. Prepare the graphite flow - channel trough 1:

[0040] S11. Crushing, screening and batching: First, crush the raw materials for preparing the graphite flow - channel trough 1. The raw materials for preparing the graphite flow - channel trough 1 are ungraphitized petroleum coke with a carbon content of 99.12%, an ash content of 0.12%, a volatile content of 0.22%, and a sulfur content of 0.11%. Then screen them into 1# material with a particle size of 5 mesh, 2# material with a particle size of 20 mesh, 3# material with a particle size of 100 mesh, 4# material with a particle size of 200 mesh, and 5# material with a particle size of 300 mesh. After that, mix the crushed materials of different particle sizes evenly according to the weight ratio of 1# material: 2# material: 3# material: 4# material: 5# material = 12:14:15:16:43 to obtain the first intermediate raw material.

[0041] S12. Dry mixing: Put the prepared first intermediate raw material into a kneading machine for dry mixing. The dry - mixing time is 45 min, and the dry - mixing temperature is 70 °C.

[0042] S13. Kneading: Put the dry - mixed first intermediate raw material and the binder into the kneading machine for kneading at a kneading temperature of 90 °C and a kneading time of 60 min to obtain the second intermediate raw material. The binder used for preparing the graphite flow - channel trough 1 is polyurethane resin, and its dosage accounts for 8.5% of the total amount of the first intermediate raw material.

[0043] S14. Shaping: The second intermediate raw material obtained by kneading is dried at a temperature of 103°C for 33 minutes using a drum drying equipment to obtain the mud material for isostatic pressing, with a volatile content of 2.97%; subsequently, the mixed mud material is directly loaded into an epoxy resin mold of a predetermined shape and pressed into shape using an isostatic press, with a forming pressure of 28 MPa and a pressure holding time of 50 minutes to obtain an intermediate product.

[0044] S15. Curing and sintering: The intermediate product after isostatic pressing is loaded into a tunnel kiln, filled with argon for protective anti-oxidation roasting, with an argon purity of 99.32%, an argon pressure of 0.65 MPa, a roasting temperature of 1130°C, a heating-up time of 52 hours, held at 1130°C for 5 hours, and then naturally cooled to room temperature.

[0045] S16. Graphitization: Then, the product after curing and sintering is put into a high-temperature graphitization furnace for graphitization treatment, with a graphitization time of 72 hours and a maximum graphitization temperature of 2450°C.

[0046] S17. Machining: It is machined into the outer dimensions required by the user using a numerical control machine tool, and the product is inspected by X-ray flaw detection to obtain the graphite flow channel groove 1.

[0047] S2. Preparation of the corundum steel-pouring head 2:

[0048] S21. Weigh the raw materials for preparing the corundum steel-pouring head 2. By mass percentage, the corundum steel-pouring head 2 is composed of the following raw materials: 36% of 2 - 6 mm granular tabular corundum aggregate, 15% of 0.5 - 2 mm granular tabular corundum aggregate, 24% of 0 - 0.5 mm granular tabular corundum powder, 6% of metallic silicon powder, 3% of metallic aluminum powder, 7% of α-Al2O3 fine powder, 5% of binder, and 4% of water. Among them, the index requirements for the raw materials for preparing the corundum steel-pouring head are as follows: the Al2O3 content in the tabular corundum aggregate is ≥99%, the Fe2O3 content is ≤0.2%, and the Na2O content is ≤0.37%; the Si content in the metallic silicon powder is ≥98%; the α-Al2O3 content in the α-Al2O3 fine powder is ≥98%, and the particle size is ≤1 micron; the Al content in the metallic aluminum powder is ≥99%. The binder used for preparing the corundum steel-pouring head 2 is polyvinyl alcohol (i.e., PVA).

[0049] S22. Prepare the co-ground powder: Premix the 0 - 0.5 mm granular tabular corundum powder, metallic silicon powder, metallic aluminum powder, and α-Al2O3 fine powder, and co-grind them in a ball mill for 33 minutes to form the co-ground powder. Five magnets are suspended under the ball mill, and the iron filings on the magnets are cleaned each time a batch of abrasive is discharged.

[0050] S23. Prepare the mud material: Knead the 2 - 6 mm granular plate-shaped corundum aggregate and the 0.5 - 2 mm granular plate-shaped corundum aggregate for 3 - 5 minutes until uniform, then add the co-ground powder obtained in step S22, add water and binder, and obtain the wet material of the embryo body of the corundum steel-pouring head after mixing and stirring evenly in a wet pan mill. At least 5 magnets are hung under the wet pan mill, and the iron filings on the magnets must be cleaned each time a batch of material is processed.

[0051] S24. Molding: Put the wet material of the embryo body into a mold and place it in an upper-mounted vibrating pressure molding machine to vibrate, pressurize and ram for molding.

[0052] S25. Drying: After demolding, put the formed steel-pouring head embryo body into an electric drying furnace, heat it from room temperature to 125 °C, with a heating-up time of 1 h, keep it at 125 °C for 10 h to dry the moisture of the steel-pouring head embryo body.

[0053] S26. Sintering: Put the dried steel-pouring head embryo body into a nitriding furnace for sintering, heat it from room temperature to 1450 °C, with a heating-up time of 11 hours, then keep it at 1450 °C for heat preservation and sintering for 12 h, and the nitrogen flow rate is 12 m 3 / h; Take it out and cool after sintering to obtain the corundum steel-pouring head 2.

[0054] S3. Finally, splice the prepared graphite runner groove 1 and the corundum steel-pouring head 2 to obtain a split-type nanocrystalline alloy steel-pouring groove.

[0055] Preparation Example 2

[0056] A split-type nanocrystalline alloy steel-pouring groove is formed by splicing the graphite runner groove 1 located at the rear section and the corundum steel-pouring head 2 located at the front section. The structure is as Figures 1 to 4 shown. The same as in Example 1, so it will not be described in detail again. The specific preparation method is as follows:

[0057] S1. Prepare the graphite runner groove 1:

[0058] S11. Crushing, screening and batching: First, crush the raw materials for preparing the graphite runner groove 1. Among them, the raw materials for preparing the graphite runner groove 1 are ungraphitized petroleum coke with a carbon content of 99.05%, an ash content of 0.15%, a volatile content of 0.27%, and a sulfur content of 0.12%. Then screen them into 1# material with a particle size of 5 mesh, 2# material with a particle size of 20 mesh, 3# material with a particle size of 100 mesh, 4# material with a particle size of 200, and 5# material with a particle size of 300 mesh. After that, mix the crushed materials with different particle sizes evenly according to the weight ratio of 1# material: 2# material: 3# material: 4# material: 5# material = 10:15:15:15:45 to obtain the first intermediate raw material.

[0059] S12. Dry mixing: Put the prepared first intermediate raw material into a kneading machine for dry mixing. The dry mixing time is 50 min, and the dry mixing temperature is 75 °C.

[0060] S13, Kneading: The first intermediate raw material after dry mixing and the binder are simultaneously put into a kneading machine for kneading. The kneading temperature is 87 °C and the kneading time is 65 min to obtain the second intermediate raw material. Among them, the binder used for preparing the graphite flow channel groove is silicone resin, and its dosage accounts for 9.2% of the total amount of the first intermediate raw material.

[0061] S14, Forming: The second intermediate raw material obtained by kneading is dried at 96 °C for 28 min using a drum drying equipment to obtain the mud for isostatic pressing, and its volatile content is 4.1%; Subsequently, the mixed mud is directly loaded into an epoxy resin mold with a predetermined shape and is pressed into shape using an isostatic press. The forming pressure is 26 MPa and the pressure holding time is 55 min to obtain the intermediate product.

[0062] S15, Curing and sintering: The intermediate product after isostatic pressing is loaded into a tunnel kiln, and argon is filled for protective anti-oxidation roasting. The purity of argon is 99.48%, the argon pressure is 0.64 MPa, the roasting temperature is 1220 °C, the heating-up time is 55 h, it is kept at 1220 °C for 7 h, and then it is naturally cooled to room temperature.

[0063] S16, Graphitization: Then the product after curing and sintering is put into a high-temperature graphitization furnace for graphitization treatment. The graphitization time is 69 h and the highest graphitization temperature is 2530 °C.

[0064] S17, Machining: It is machined into the external dimensions required by the user using a numerical control machine tool, and the product is inspected by X-ray flaw detection to obtain the graphite flow channel groove 1.

[0065] S2. Preparation of the corundum steel-pouring head 2:

[0066] S21, Weigh the raw materials for preparing the corundum steel-pouring head 2. By mass percentage, the corundum steel-pouring head 2 is composed of the following raw materials: 32% of 2 - 6 mm granular plate-shaped corundum aggregate, 12% of 0.5 - 2 mm granular plate-shaped corundum aggregate, 26% of 0 - 0.5 mm granular plate-shaped corundum powder, 7% of metallic silicon powder, 4% of metallic aluminum powder, 8% of α-Al2O3 fine powder, 6% of binder, and 5% of water. Among them, the index requirements for the raw materials used for preparing the corundum steel-pouring head are as follows: the Al2O3 content in the plate-shaped corundum aggregate is ≥99%, the Fe2O3 content is ≤0.2%, and the Na2O content is ≤0.37%; the Si content in the metallic silicon powder is ≥98%; the α-Al2O3 content in the α-Al2O3 fine powder is ≥98% and the particle size is ≤1 micron; the Al content in the metallic aluminum powder is ≥99%. The binder used for preparing the corundum steel-pouring head is ethylene-vinyl alcohol copolymer (PVOH).

[0067] S22. Prepare the co-ground powder: Premix the 0 - 0.5 mm granular plate-shaped corundum powder, metallic silicon powder, metallic aluminum powder, and α-Al₂O₃ fine powder, and co-grind them in a ball mill for 33 minutes to form the co-ground powder. Hang 5 magnets under the ball mill, and clean the iron filings on the magnets each time a batch of abrasive is produced.

[0068] S23. Prepare the mud material: Knead the 2 - 6 mm granular plate-shaped corundum aggregate and the 0.5 - 2 mm granular plate-shaped corundum aggregate for 3 - 5 minutes until uniform, then add the co-ground powder obtained in step S22, add water and binder, and mix and stir evenly in a wet pan mill to obtain the wet material of the embryo body of the corundum steel pouring head. Hang at least 5 magnets under the wet pan mill, and clean the iron filings on the magnets each time a batch of material is processed.

[0069] S24. Molding: Put the wet material of the embryo body into a mold, and place it in an upper-mounted vibration pressure molding machine to vibrate, pressurize, and ram to form.

[0070] S25. Drying: After demolding, put the formed steel pouring head embryo body into an electric heating drying furnace, heat it from room temperature to 130 °C, with a heating-up time of 1 hour, keep it at 130 °C for 11 hours to dry the moisture of the steel pouring head embryo body.

[0071] S26. Sintering: Put the dried steel pouring head embryo body into a nitriding furnace for sintering, heat it from room temperature to 1500 °C, with a heating-up time of 11 hours, then keep it at 1450 °C for heat preservation and sintering for 11 hours, and the nitrogen flow rate is 11 m 3 / h; After sintering, take it out and cool to obtain the corundum steel pouring head 2.

[0072] S3. Finally, splice the prepared graphite runner groove 1 and the corundum steel pouring head 2 to obtain a split-type nanocrystalline alloy steel pouring groove.

[0073] Preparation Example 3

[0074] A split-type nanocrystalline alloy steel pouring groove is formed by splicing the graphite runner groove 1 located at the rear section and the corundum steel pouring head 2 located at the front section. The structure is as Figures 1 to 4 shown. The same as in Example 1, so it will not be elaborated here. Its specific preparation method is as follows:

[0075] S1. Prepare the graphite runner groove 1:

[0076] S11. Scrap, screening and batching: First, the raw materials for preparing the graphite runner groove 1 are crushed. The raw materials for preparing the graphite runner groove 1 are ungraphitized petroleum coke with a carbon content of 99.38%, an ash content of 0.32%, a volatile content of 0.33%, and a sulfur content of 0.14%. Then, it is screened into No. 1 material with a particle size of 5 mesh, No. 2 material with a particle size of 20 mesh, No. 3 material with a particle size of 100 mesh, No. 4 material with a particle size of 200, and No. 5 material with a particle size of 300 mesh. After that, the crushed materials with different particle sizes are mixed evenly according to the weight ratio of No. 1 material: No. 2 material: No. 3 material: No. 4 material: No. 5 material = 13:13:13:15:46 to obtain the first intermediate raw material.

[0077] S12. Dry mixing: Put the prepared first intermediate raw material into a kneading machine for dry mixing. The dry mixing time is 57 min and the dry mixing temperature is 78 °C.

[0078] S13. Kneading: Put the dry-mixed first intermediate raw material and the binder into the kneading machine for kneading at the same time. The kneading temperature is 93 °C and the kneading time is 68 min to obtain the second intermediate raw material. The binder used for preparing the graphite runner groove is polyimide resin, and its dosage accounts for 10.4% of the total amount of the first intermediate raw material.

[0079] S14. Molding: The second intermediate raw material obtained by kneading is dried at 112 °C for 36 min by a drum drying device to obtain the mud for isostatic pressing, and its volatile content is 3.7%. Subsequently, the mixed mud is directly loaded into an epoxy resin mold with a predetermined shape and pressed into shape by an isostatic press. The molding pressure is 30 MPa and the pressure holding time is 48 min to obtain an intermediate product.

[0080] S15. Curing and sintering: Put the intermediate product after isostatic pressing into a tunnel kiln, fill it with argon for protective anti-oxidation roasting. The purity of argon is 99.39%, the argon pressure is 0.59 MPa, the roasting temperature is 1190 °C, the heating-up time is 48 h, keep it at 1190 °C for 9 h, and then cool it naturally to room temperature.

[0081] S16. Graphitization: Then put the product after curing and sintering into a high-temperature graphitization furnace for graphitization treatment. The graphitization time is 69 h and the highest graphitization temperature is 2390 °C.

[0082] S17. Machining: Use a numerical control machine tool to machine it into the external dimensions required by the user, and perform X-ray flaw detection on the product to obtain the graphite runner groove 1.

[0083] S2. Prepare the corundum steel-pouring head 2:

[0084] S21. Weigh the raw materials for preparing the corundum steel-pouring head 2. By mass percentage, the corundum steel-pouring head 2 is composed of the following raw materials: 35% of 2 - 6 mm granular tabular corundum aggregate, 12% of 0.5 - 2 mm granular tabular corundum aggregate, 28% of 0 - 0.5 mm granular tabular corundum powder, 5% of metallic silicon powder, 3% of metallic aluminum powder, 6% of α-Al2O3 micropowder, 7% of binder, and 4% of water. Among them, the index requirements for the raw materials for preparing the corundum steel-pouring head are as follows: the Al2O3 content in the tabular corundum aggregate is ≥99%, the Fe2O3 content is ≤0.2%, and the Na2O content is ≤0.37%; the Si content in the metallic silicon powder is ≥98%; the α-Al2O3 content in the α-Al2O3 micropowder is ≥98%, and the particle size is ≤1 micron; the Al content in the metallic aluminum powder is ≥99%. The binder used for preparing the corundum steel-pouring head is clay.

[0085] S22. Prepare the co-ground powder: Premix the 0 - 0.5 mm granular tabular corundum powder, metallic silicon powder, metallic aluminum powder, and α-Al2O3 micropowder, and co-grind them in a ball mill for 33 min to form the co-ground powder. Five magnets are suspended under the ball mill, and the iron filings on the magnets are cleaned each time a batch of abrasive is produced.

[0086] S23. Prepare the mud material: Knead the 2 - 6 mm granular tabular corundum aggregate and 0.5 - 2 mm granular tabular corundum aggregate for 3 - 5 min until uniform, then add the co-ground powder prepared in step S22, add water and binder, and mix and stir evenly in a wet pan mill to obtain the wet blank material of the corundum steel-pouring head. At least five magnets are suspended under the wet pan mill, and the iron filings on the magnets must be cleaned each time a batch of material is processed.

[0087] S24. Molding: Put the wet blank material into a mold and place it in an upper-mounted vibration pressure molding machine to vibrate, pressurize, and ram to form.

[0088] S25. Drying: After demolding, put the formed steel-pouring head blank into an electric drying furnace, heat it from room temperature to 133°C, with a heating-up time of 1 h, keep it at 130°C for 12 h to dry the moisture of the steel-pouring head blank.

[0089] S26. Sintering: Put the dried steel-pouring head blank into a nitriding furnace for sintering, heat it from room temperature to 1530°C, with a heating-up time of 11 hours, then keep it at 1520°C for heat preservation and sintering for 13 h, and the nitrogen flow rate is 12 m 3 / h; After sintering, take it out and cool to obtain the corundum steel-pouring head 2.

[0090] S3. Finally, splice the prepared graphite runner groove 1 and the corundum steel-pouring head 2 to obtain a split-type nanocrystalline alloy steel-pouring groove.

[0091] Perform performance tests on the graphite runner grooves and corundum steel-pouring heads prepared in Preparation Examples 1 - 3, and the data are shown in Tables 1 and 2 below.

[0092] Table 1 Performance of graphite flow channels prepared in Preparation Examples 1 to 3

[0093]

[0094] Table 2 Performance of corundum steel-pouring heads prepared in Preparation Examples 1 to 3

[0095]

[0096] The above embodiments only exemplarily illustrate the concept and technical solutions of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

[0097] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A split-type nanocrystalline alloy steel casting trough, characterized in that It is formed by splicing a graphite runner groove located in the rear section and a corundum steel-pouring head located in the front section. The graphite runner groove is made of graphite, the corundum steel-pouring head is made of plate-shaped corundum, and the graphite runner groove and the corundum steel-pouring head are detachably connected through a lapping structure.

2. The split nano-crystalline alloy steel casting groove according to claim 1, characterized in that, The graphite runner groove includes a horizontally distributed groove bottom. Groove walls extending upward are provided on both sides of the groove bottom and on the side away from the corundum steel-pouring head. A blanking pipe with a downward opening is provided at one end of the groove bottom away from the corundum steel-pouring head. The corundum steel-pouring head includes a steel-pouring head body. The upper surface of the steel-pouring head body has a diversion arc surface distributed upward away from the graphite runner groove, and retaining edges extending upward are respectively provided on both sides of the steel-pouring head body.

3. The split nanocrystalline alloy steel casting ladle according to claim 2, wherein The central axis of the blanking pipe is vertically distributed with respect to the groove bottom, and the overall shape of the blanking pipe is a cone with a larger upper part and a smaller lower part.

4. The split nanocrystalline alloy steel pouring trough according to claim 3, characterized in that, The taper of the blanking pipe is (1:10) to (1:20).

5. The split nanocrystalline alloy steel casting ladle according to claim 2, wherein The transition between the groove wall and the groove bottom and between the retaining edge and the steel-pouring head body is an arc surface.

6. The split nano-crystalline alloy steel casting ladle according to claim 2, characterized in that, The radian of the diversion arc surface is R500mm to R1000mm.

7. The split nano-crystalline alloy steel casting ladle according to any one of claims 1 to 6, characterized in that The lapping structure includes an upper lapping head and a lower lapping head that are seamlessly lapped.

8. The split nanocrystalline alloy steel casting ladle according to claim 7, characterized in that, Both the upper lapping head and the lower lapping head are distributed along the width direction of the split nanocrystalline alloy steel-pouring groove.

9. The split nanocrystalline alloy steel casting ladle according to claim 7, wherein, The upper lapping head is arranged at one end of the corundum steel-pouring head close to the graphite runner groove, and the lower lapping head is arranged at one end of the graphite runner groove close to the corundum steel-pouring head.

10. The split nanocrystalline alloy steel casting ladle according to claim 7, characterized in that, The cross-sectional shapes of both the upper lapping head and the lower lapping head are rectangular.

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