Low-density steel guide horn and manufacturing method therefor

Abstract

The present invention belongs to the technical field of mechanical components. Disclosed are a low-density steel guide horn and a manufacturing method therefor. The chemical composition and mass percentage of the low-density steel guide horn are respectively: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, and the balance being Fe. The manufacturing method for the low-density steel guide horn comprises the steps: material preparation; guide horn housing manufacturing; raw material melting to form molten steel; deoxidation and slag removal treatment of the molten steel; adjusting the mass percentage content of Al, Ce, and Fe in the molten steel to meet set requirements for the composition of the low-density steel guide horn; molten steel pouring for forming the guide horn; and water toughening treatment of the guide horn. The present invention controls the chemical composition of the low-density steel to reduce the content of Mn in the steel and ensure the strength of the steel, controls the content of microalloy elements in the steel and adds rare earth to improve the machinability of the steel, and accurately controls the time of adding the rare earth in the smelting process to improve the quality of the guide horn.

Description

A low-density steel guide tooth and its manufacturing method Technical Field

[0001] This invention belongs to the field of mechanical component technology and relates to a low-density steel guide tooth and its manufacturing method. Background Technology

[0002] The industrial age has brought increasingly prominent environmental problems, such as global warming and energy depletion. The International Energy Outlook report indicates that approximately 23% of carbon dioxide emissions originate from vehicular traffic, and this figure is projected to double by 2050. Furthermore, transportation is the largest end-user of petroleum and other liquid fuels, accounting for over 50% of consumption. Therefore, reducing carbon dioxide emissions and fuel consumption rates is a challenge facing the automotive industry. One of the most important ways to achieve this is to reduce the weight of the vehicle body structure. For example, a compact car's body-in-white weighs around 350 kg. Reducing the body structure weight by 10% can save 6%–8% on fuel and reduce exhaust emissions by 5%–6%. Therefore, lightweighting is the future development path for the automotive industry.

[0003] Currently, guide teeth for construction machinery vehicles are mainly forged from 42CrMo steel, with a density of 7.8 g / cm³. 3 A single vehicle contains over 300 components, and these components are significantly heavier than other structural parts relative to the overall vehicle weight, making lightweighting essential. Fe-Mn-Al-C high-strength steel is a widely studied low-density steel; adding 1% Al to the steel reduces its density by 0.101 g / cm³. 3 For every 1% of carbon added to steel, the density decreases by 0.41 g / cm³. 3 For every 1% Mn added to steel, the density decreases by 0.0086 g / cm³. 3 Its density can reach 6.2 g / cm³. 3 -7.2g / cm 3 .

[0004] Fe-Mn-Al-C series low-density steels have high Mn and Al content, making them prone to reaction with O and S during smelting, which reduces the internal quality of the material. To prevent oxidation, a vacuum induction furnace must be used for smelting. At the same time, the high C, Mn, and Al content results in poorer machinability and weldability compared to traditional steel materials. Currently, low-density steel is mainly used in sheet metal production, but sheet metal processing and welding are prone to cracking, limiting the widespread use of low-density steel in lightweight structural component manufacturing. Summary of the Invention

[0005] (I) Purpose of the Invention

[0006] The purpose of this invention is to provide a low-density steel guide tooth and its manufacturing method. The invention uses low-density steel to replace traditional high-strength steel to achieve lightweight manufacturing of the guide tooth. In order to reduce the processing workload of low-density steel structural components, the low-density steel guide tooth is manufactured by casting. At the same time, by adjusting the chemical composition and heat treatment process based on Fe-Mn-Al-C system low-density steel, the machinability of low-density steel is improved, thereby achieving low-cost and high-efficiency manufacturing of low-density steel guide teeth.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, the present invention provides a low-density steel guide tooth, wherein the chemical composition and mass percentage of the guide tooth are as follows: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, and the balance is Fe.

[0009] The present invention also provides a method for manufacturing low-density steel guide teeth, which includes the following steps:

[0010] S1. Material preparation

[0011] Prepare the raw materials needed for smelting, which contain the components and impurities of low-density steel guide teeth;

[0012] S2, Induction of toothed shell manufacturing

[0013] The induced tooth shell was prepared according to the three-dimensional model of the induced tooth;

[0014] S3, Raw materials melt to form molten steel.

[0015] Add the raw materials prepared in step S1 into the medium frequency induction furnace and melt them completely;

[0016] S4. Deoxidation and slag removal treatment of molten steel

[0017] Ferrosilicon is added to the molten steel to deoxidize it, and the slag is collected and removed multiple times.

[0018] S5. Adjust the mass percentage content of Al, Ce and Fe in the molten steel to meet the composition requirements of the low-density steel induction tooth.

[0019] S6. Molten steel pouring to induce tooth formation;

[0020] S7, Induced tooth hydroforming treatment.

[0021] In step S1, the low-density steel guide tooth comprises, by mass percentage: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, with the balance being Fe.

[0022] In step S2, a wax model is manufactured using 3D printing based on the three-dimensional model of the induced tooth. The wax model is then dipped in an aqueous solution of quartz sand and zircon sand of different particle sizes to form a shell with a thickness of 5mm-8mm on the surface. The shell is placed in a heating furnace and heated at 850℃-950℃ for 2-3 hours. After all the wax inside the shell has melted and evaporated, the induced tooth-shaped shell is formed.

[0023] In step S3, the raw materials prepared in step S1 are added to the medium-frequency induction furnace and heating is started. During the heating process, the power is continuously increased until the temperature reaches 1610℃~1680℃, so that the raw materials are completely melted.

[0024] In step S4, ferrosilicon is added to the molten steel to deoxidize it. At the same time, a slag collector is added to the surface of the molten steel to collect impurities inside the steel on the surface of the medium-frequency induction furnace. The impurities are then removed using tools. The slag collection process is repeated multiple times until the surface of the molten steel is visually clean and free of impurities. At this point, the chemical composition of the molten steel is tested online.

[0025] In step S5, the difference between the actual Al content and the set value in the chemical composition tested in step S4 is compared. Aluminum wire is added to the molten steel to make the mass percentage content of Al reach the set value. Rare earth alloy is added to the molten steel to adjust the mass percentage content of Ce and Fe in the molten steel to reach the set value.

[0026] In step S6, after adding rare earth for 1 to 2 minutes, the molten steel is poured into the induced tooth-shaped shell at a pouring temperature of 1520 to 1610°C.

[0027] In step S6, after the induced teeth are cast and formed, a saw is used to cut the riser.

[0028] In step S7, after the riser is processed, the low-density steel guide tooth is subjected to water toughening treatment. The water toughening treatment includes: holding at 950℃~1050℃ for 0.5h~1h, cooling in oil; then holding at 690℃ for 0.2~0.3h, cooling in water to obtain the final state of the guide tooth.

[0029] (III) Beneficial Effects

[0030] The low-density steel guide teeth and their manufacturing method provided by the above technical solution have the following advantages: Beneficial effects:

[0031] (1) By controlling the chemical composition of low-density steel, the Mn content in the steel is reduced and the strength of the steel is guaranteed;

[0032] (2) Control the content of microalloying elements in steel, add rare earth to improve the workability of steel, and precisely control the addition time of rare earth in the smelting process to improve the quality of the induction teeth.

[0033] (3) Improved the chemical composition of low-density steel, determined the appropriate addition time and method, and achieved a high aluminum alloy content;

[0034] (4) The strength of low-density steel can reach 900MPa-1100MPa; the weight of low-density steel guide teeth is reduced by about 10% compared with 42CrMo material guide teeth. Detailed Implementation

[0035] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to examples.

[0036] This embodiment first provides a low-density steel guide tooth, the chemical composition and mass percentage of which are: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, with the balance being Fe.

[0037] Based on the chemical composition of the aforementioned easily machinable low-density steel, this embodiment manufactures the guide teeth of low-density steel using a medium-frequency induction furnace and 3D-printed sand molds, thereby achieving overall weight reduction of the vehicle.

[0038] The manufacturing method of low-density steel guide teeth includes the following steps:

[0039] S1. Material preparation

[0040] Prepare the raw materials needed for smelting. The raw materials contain the components and impurities of low-density steel guide teeth. The components of low-density steel guide teeth, by mass percentage, include: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, with the balance being Fe.

[0041] In this embodiment, recycled materials and scrap were used in the preparation of raw materials. By mass percentage, 40% was recycled Fe-Mn-Al-C series low-density steel plate (chemical composition: C 1.0-1.2%, Al 10-12%, Si 0.3-0.9%, Mn 25-30%, Fe as balance), and 60% was high-manganese steel processing scrap. The weight of a single furnace of molten steel was 200 kg. Based on this part of the raw materials, the composition of the low-density steel guide tooth containing the above components and percentages was obtained.

[0042] S2, Induction of toothed shell manufacturing

[0043] The wax model is manufactured using 3D printing based on the three-dimensional model of the guide tooth. The wax model is then dipped in an aqueous solution of quartz sand and zircon sand of different particle sizes to form a shell with a thickness of 5-8 mm. Finally, the shell is placed in a heating furnace and heated at 850-950℃ for 2-3 hours. After all the wax inside the shell has melted and evaporated, the guide tooth shell is removed.

[0044] S3, Raw materials melt to form molten steel.

[0045] Add the raw materials prepared in step S1 into the medium frequency induction furnace and start heating. During the heating process, continuously increase the power until the temperature reaches 1610℃~1680℃, at which point all the raw materials will melt.

[0046] S4. Deoxidation and slag removal treatment of molten steel

[0047] Ferrosilicon is added to the molten steel to deoxidize it. Simultaneously, a slag-collecting agent is added to the surface of the molten steel to gather impurities from inside the steel onto the surface of the medium-frequency induction furnace. These impurities are then removed using tools. This slag-collecting process is repeated multiple times until the surface of the molten steel appears clean and free of impurities. At this point, the molten steel is sampled online for chemical composition testing.

[0048] S5. Adjust the mass percentage content of Al, Ce, and Fe in the molten steel to meet the composition requirements for low-density steel induction teeth.

[0049] Compare the difference between the actual Al content and the set value in the chemical composition tested in step S4, add aluminum wire to the molten steel to make the mass percentage content of Al reach the set value; add rare earth alloy to the molten steel to adjust the mass percentage content of Ce and Fe in the molten steel to reach the set value.

[0050] The rare earth alloy used in this embodiment contains Ce and Fe elements, and has a density of approximately 7.8 g / cm³. 3 It has a density similar to that of steel, so it will not float on top of molten steel.

[0051] S6. Molten steel pouring, inducing tooth forming

[0052] After adding rare earth elements for 1 to 2 minutes, pour the molten steel into the induction tooth shell at a pouring temperature of 1520 to 1610℃.

[0053] The desired induced tooth was obtained, and the tested density result was 7.2 g / cm³. 3 This resulted in a reduction in weight. After smelting, the risers were cut using a conventional saw, which made the process easy and resulted in good surface quality.

[0054] S7, Induced Tooth Hydration Treatment

[0055] After riser processing, the low-density steel guide teeth undergo water quenching treatment. The water quenching treatment includes: holding at 950℃~1050℃ for 0.5h~1h, cooling in oil; then holding at 690℃ for 0.2~0.3h, cooling in water, to obtain the final state of the guide teeth.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A low-density steel guide tooth, characterized in that, The chemical composition and mass percentage of the induced teeth are as follows: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, with the balance being Fe.

2. A method for manufacturing low-density steel guide teeth, characterized in that, Includes the following steps: S1. Material preparation Prepare the raw materials needed for smelting, which contain the components and impurities of low-density steel guide teeth; S2, Induction of toothed shell manufacturing The induced tooth shell was prepared according to the three-dimensional model of the induced tooth; S3, Raw materials melt to form molten steel. Add the raw materials prepared in step S1 into the medium frequency induction furnace and melt them completely; S4. Deoxidation and slag removal treatment of molten steel Ferrosilicon is added to the molten steel to deoxidize it, and the slag is collected and removed multiple times. S5. Adjust the mass percentage content of Al, Ce and Fe in the molten steel to meet the composition requirements of the low-density steel induction tooth. S6. Molten steel pouring to induce tooth formation; S7, Induced tooth hydroforming treatment.

3. The method for manufacturing low-density steel guide teeth according to claim 2, characterized in that, In step S1, the low-density steel guide tooth comprises, by mass percentage: C 0.7-1.1%, Al 5-11%, Si 0.3-0.9%, Mn 10-15%, Ni 3-5%, V 0.3-0.8%, Ce 0.001-0.002%, with the balance being Fe.

4. The method for manufacturing low-density steel guide teeth according to claim 3, characterized in that, In step S2, a wax model is manufactured using 3D printing based on the three-dimensional model of the induced tooth. Then, the wax model is dipped in an aqueous solution of quartz sand and zircon sand of different particle sizes to form a shell with a thickness of 5mm-8mm on the surface. The shell is placed in a heating furnace and heated at 850℃-950℃ for 2h-3h. After all the wax inside the shell has melted and evaporated, the induced tooth-shaped shell is formed.

5. The method for manufacturing low-density steel guide teeth according to claim 4, characterized in that, In step S3, the raw materials prepared in step S1 are added to the medium-frequency induction furnace and heating is started. During the heating process, the power is continuously increased until the temperature reaches 1610℃~1680℃, so that the raw materials are completely melted.

6. The method for manufacturing low-density steel guide teeth according to claim 5, characterized in that, In step S4, ferrosilicon is added to the molten steel to deoxidize it. At the same time, a slag collector is added to the surface of the molten steel to collect impurities inside the steel on the surface of the medium-frequency induction furnace. The impurities are then removed using tools. The slag collection process is repeated multiple times until the surface of the molten steel is visually clean and free of impurities. At this point, the chemical composition of the molten steel is tested online.

7. The method for manufacturing low-density steel guide teeth according to claim 6, characterized in that, In step S5, the difference between the actual Al content and the set value in the chemical composition tested in step S4 is compared. Aluminum wire is added to the molten steel to make the mass percentage content of Al reach the set value. Rare earth alloy is added to the molten steel to adjust the mass percentage content of Ce and Fe in the molten steel to reach the set value.

8. The method for manufacturing low-density steel guide teeth according to claim 7, characterized in that, In step S6, after adding rare earth for 1 to 2 minutes, the molten steel is poured into the induced tooth-shaped shell at a pouring temperature of 1520 to 1610℃.

9. The method for manufacturing low-density steel guide teeth according to claim 8, characterized in that, In step S6, after the induced teeth are cast and formed, the riser is cut using a saw.

10. The method for manufacturing low-density steel guide teeth according to claim 9, characterized in that, In step S7, after the riser is processed, the low-density steel guide tooth is subjected to water toughening treatment. The water toughening treatment includes: holding at 950℃~1050℃ for 0.5h~1h, cooling in oil; then holding at 690℃ for 0.2~0.3h, cooling in water to obtain the final state of the guide tooth.