Ultra-pure gear steel inclusion removal method based on interface activation energy regulation and control

Abstract

The invention discloses an ultra-pure gear steel inclusion removal method based on interface activation energy regulation and control, and belongs to the technical field of electroslag remelting. The removal method comprises the following steps: surface quality control of an electrode cast ingot, uniform coating of an anti-oxidation coating on the surface of the electrode cast ingot, electroslag system proportioning, current and voltage gradient control, gas atmosphere control in an electroslag furnace, and deep removal of harmful inclusions such as AlO and TiN through optimization of electrode components, slag system design and dynamic process control. The ultra-pure gear steel produced through the method is uniform in chemical component, inclusions in cast ingots can be effectively removed, and the total amount of the inclusions is reduced.

Description

Technical Field

[0001] This invention belongs to the field of electroslag remelting technology, and specifically relates to a method for removing inclusions in ultrapure gear steel based on the regulation of interface activation energy. Background Technology

[0002] Gear steel is widely used in the manufacture of automotive transmissions, wind turbine gearboxes, and aerospace transmission systems. With societal and technological advancements, higher demands are being placed on the fatigue strength and wear resistance of gear steel. Inclusions such as Al2O3 and TiN in gear steel can cause stress concentration, leading to fatigue fracture and limiting the service life of gears.

[0003] In industrial production, techniques such as calcium treatment for inclusion modification, refining slag system optimization, and protective casting are commonly used. Calcium treatment can convert Al2O3 into low-melting-point calcium aluminate, but its effectiveness is limited by many conditions and it is difficult to completely eliminate micron-sized inclusions. High-basicity refining slag has a certain adsorption capacity for oxides, but it is ineffective in removing TiN. Protective casting can effectively reduce secondary oxidation of molten steel, but it cannot avoid the problem of inclusion aggregation during solidification. In addition, the above methods have a removal rate of less than 50% for inclusions smaller than 20 μm, especially TiN inclusions of 1-5 μm.

[0004] Electroslag remelting (ESR), as a refining method for high-end special steels and high-temperature alloys, can achieve inclusion removal, microstructural densification, and fine-tuning of chemical composition. However, traditional ESR processes have significant limitations in smelting ultrapure gear steel: Firstly, the slag system design is not targeted enough. Conventional CaF2-CaO-Al2O3 ternary slag systems have limited ability to remove Al2O3, low titanium recovery, and high interfacial activation energy and poor wettability between the slag system and Al2O3 and TiN inclusions, making effective adsorption and removal difficult. Secondly, the process control window is too wide. Fixed current and voltage modes can easily lead to excessively deep molten pools and turbulent temperature fields, limiting the floating path and time of inclusions. Thirdly, the atmosphere protection and melting rate are mismatched. Simple constant-flow argon protection mode cannot dynamically suppress atmosphere fluctuations at different remelting stages, which may lead to secondary oxidation of the molten steel, generating new TiN or Al2O3 inclusions. Therefore, there is an urgent need in this field for an innovative electroslag remelting method that can fundamentally optimize the slag composition to reduce the interfacial energy barrier to harmful inclusions, and achieve dynamic synergistic control of current, voltage parameters and atmosphere protection, thereby efficiently removing inclusions from gear steel and meeting the stringent requirements of high-end equipment for material purity. Summary of the Invention

[0005] This invention provides a method for removing inclusions from ultrapure gear steel based on interface activation energy regulation. It aims to solve the problems of low removal efficiency of inclusions such as Al2O3 and TiN in gear steel, large fluctuations in titanium yield, and crude process control in traditional electroslag remelting. The method achieves deep removal of inclusions through dynamic joint control of slag composition, electrical parameters, and atmosphere.

[0006] To achieve the above effects, the technical solution adopted by the present invention is: a method for deep removal of inclusions in ultrapure gear steel by electroslag remelting based on interface activation energy regulation, the method comprising the following steps: (1) Surface quality control of electrode ingots: control the chemical composition of electrode ingots and apply an anti-oxidation coating; (2) Electroslag remelting slag system formulation and pretreatment: The electroslag remelting slag system is heated from room temperature to 900-1000℃ and kept at that temperature for 4-5 hours; a special slag system is prepared and baked. The chemical composition of the slag system includes: CaF2, CaO, MgO, Al2O 3、 TiO2; (3) Current-voltage gradient control: The current-voltage ratio is dynamically controlled in four stages during the electroslag remelting process; (4) Gas atmosphere control in electroslag furnace: Argon protection throughout the process and dynamic flow adjustment.

[0007] The special slag system in step (2) of the present invention contains the following chemical components by mass percentage: CaF2: 48-56%, CaO: 20-28%, MgO: 1-2%, Al2O3: 3-8%, TiO2: 8-10%.

[0008] In step (2) of this invention, the viscosity of the electroslag system at 1500℃ is 0.015~0.020 Pa·S, and the viscosity at 1600℃ is 0.018~0.025 Pa·S; the slag-gold interface activation energy between the slag system and the target inclusions (Al2O3, TiN) is adjusted to the optimal range, with the interface activation energy of Al2O3 being 120~150 kJ / mol and the interface activation energy of TiN being 150~180 kJ / mol.

[0009] In step (3) of this invention, the four-stage dynamic control is as follows: voltage 20-25V and current 1.6-1.8kA during the arc initiation period; voltage 25-28V and current 1.6-2.4kA during the slag formation period; voltage 30-35V and current 2.4-2.7kA during the remelting period; and voltage 18-20V and current 2.0-2.6kA during the shrinkage compensation period.

[0010] In step (4) of the present invention, the dynamic argon flow rate is controlled as follows: 220-260 L / min during the arc initiation and slag formation periods, 150-180 L / min during the remelting period, and 100-150 L / min during the feeding period.

[0011] The antioxidant coating in step (1) of the present invention is a nano-yttrium oxide dispersion-reinforced aluminate coating with a coating thickness of 0.2-0.5 mm, a nano-yttrium oxide content of 4-9%, and a nano-yttrium oxide particle size range of 10-100 nm.

[0012] In step (1) of this invention, the chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.15-0.22%, Si: 0.15-0.25%, Mn: 0.65-0.95%, P≤0.0030%, S≤0.0020%, Cr: 0.85-1.15%, Ni: 0.40-0.5%, Al: 0.015-0.055%, Nb: 0.015-0.030%, Mo: 0.11-0.15%, with the remainder being Fe and unavoidable impurities.

[0013] The method described in this invention yields ultrapure gear steel electroslag ingots with an inclusion number density of ≤4.06 inclusions / mm. 2 The number of inclusions was reduced by more than 30%; the TiN number density of electroslag ingots was ≤2.1 inclusions / mm. 2 The TiN removal rate exceeds 40%.

[0014] The method of the present invention stably controls the total oxygen content of molten steel to below 10 ppm and achieves a titanium element recovery rate of over 92%.

[0015] The design concept of this invention is to incorporate the activation energy of the slag-gold interface as a key control parameter into the design of the electroslag remelting slag system. By controlling the slag system ratio, the activation energy of the slag-gold-inclusion interface is kept within a specific range (Al2O3: 120-150 kJ / mol, TiN: 150-180 kJ / mol), reducing the energy barrier for inclusion adsorption and dissolution by the slag phase and accelerating mass transfer at the slag-gold interface. Adjusting the slag system ratio creates an oxygen potential gradient in the slag pool, enabling the targeted adsorption and removal of inclusions such as TiN and Al2O3. Adding 8-10% TiO2 can utilize the variable valence characteristics of Ti... 3+ / Ti 4+Valence equilibrium reactions reduce Ti element burn-off and decrease the formation of Ti oxide and Ti nitride inclusions. Furthermore, this invention employs a nano-yttrium oxide dispersion-reinforced aluminate coating as the electrode's anti-oxidation layer. Compared to traditional coatings, the nano-coating exhibits higher density and high-temperature stability, more effectively preventing surface oxidation during electrode heating. Simultaneously, yttrium oxide nanoparticles dissolve into the slag pool at high temperatures, reacting with high-melting-point brittle oxides such as Al₂O₃ to generate low-melting-point rare-earth aluminates, which encapsulate precipitated TiN inclusions, promoting inclusion spheroidization and facilitating their collision and flotation. The yttrium element in the yttrium oxide can dissolve nitrogen, inhibiting the precipitation of coarser TiN. Through the coordinated control of four-stage dynamic electrical parameters and the furnace atmosphere, a deep and gentle molten pool is formed within the furnace, extending the time for metal droplets to pass through the slag pool and for inclusions to float. An argon flow gradient regime ensures an inert atmosphere within the furnace while preventing high-speed gas flow from interfering with the slag pool and molten metal surface.

[0016] The beneficial effects of adopting the above technical solution are as follows: the ultra-pure gear steel produced by this invention achieves a comprehensive improvement in composition control, cleanliness and solidification quality, reduces the number of inclusions by more than 30%, removes TiN by more than 40%, effectively inhibits secondary oxidation of molten steel, stably controls the total oxygen content of molten steel to below 10ppm, stabilizes the titanium element recovery rate at more than 92%, and produces a uniform and dense ingot structure, which enables a leap in the fatigue life and reliability of gear steel. Moreover, it has a wide process window and is easy to produce stably in industrial applications. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments.

[0018] Comparative Example (1) Electrode ingot preparation: The chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.17%, Si: 0.20%, Mn: 0.80%, Cr: 1.10%, Ni: 0.42%, Al: 0.044%, Nb: 0.025%, Mo: 0.13%, Ti: 0.08%; the remainder is Fe and unavoidable impurities, and the surface is polished.

[0019] (2) Electroslag slag system ratio: The electroslag remelting slag system is heated from room temperature to 1000℃ and kept at that temperature for 4 hours. The chemical composition of the slag system by mass percentage includes: CaF2: 60%, CaO: 20%, Al2O3: 20%, and the remainder is unavoidable impurities. (3) Smelting process parameters: During the electroslag remelting process, the current and voltage remain stable at 20V and 2.0kA. The slag addition rate is 5kg / min.

[0020] (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The gas atmosphere control in electroslag furnace during smelting is as follows: Argon gas flow rate is 150L / min throughout the process.

[0021] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling. Example 1

[0022] A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation includes the following steps: (1) Electrode ingot preparation and surface quality control: The chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.17%, Si: 0.20%, Mn: 0.80%, Cr: 1.10%, Ni: 0.42%, Al: 0.044%, Nb: 0.025%, Mo: 0.13%, Ti: 0.08%, with the remainder being Fe and unavoidable impurities; The surface of the electrode ingot is uniformly coated with an anti-oxidation coating, which is a nano-yttrium oxide dispersion-reinforced aluminate coating with a yttrium oxide content of 4%, a thickness of 0.2~0.5 mm, and a nano-yttrium oxide particle size of 10 nm.

[0023] (2) Electroslag remelting slag system ratio: The electroslag remelting slag system was heated from room temperature to 1000℃ and kept at that temperature for 4h. The chemical composition of the slag system by mass percentage included: CaF2: 56%, CaO: 32%, MgO: 2%, Al2O3: 2%, TiO2: 8%, and the remainder were unavoidable impurities. The viscosity of the slag system was 0.015 Pa·S at 1500℃ and 0.018 Pa·S at 1600℃.

[0024] (3) Current and voltage gradient control: The current and voltage during the electroslag remelting process are controlled in four stages, as follows: voltage 25V and current 1.8kA during the arc initiation period; voltage 28V and current 2.4kA during the slag formation period; voltage 35V and current 2.7kA during the remelting period; voltage 20V and current 2.6kA during the feeding period. (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The partial pressure of gas in the furnace is changed with the current and voltage during the smelting process. The gas atmosphere in the electroslag furnace is controlled as follows: flow rate 220L / min during arc initiation, flow rate 220L / min during slag formation, 180L / min during remelting, 150L / min during feeding, and the total oxygen content of molten steel is stably controlled at 8ppm.

[0025] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling. Example 2

[0026] A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation includes the following steps: (1) Surface quality control of electrode ingots: The chemical composition of electrode ingots is controlled by mass percentage as follows: C: 0.16%, Si: 0.16%, Mn: 0.90%, Cr: 1.0%, Ni: 0.5%, Al: 0.055%, Nb: 0.020%, Mo: 0.14%, Ti: 0.08%, with the remainder being Fe and unavoidable impurities; An anti-oxidation coating is uniformly applied to the surface of the electrode ingots; The anti-oxidation coating is a nano-yttrium oxide dispersion-reinforced aluminate coating with a yttrium oxide content of 9%, a coating thickness of 0.2-0.5 mm, and a nano-yttrium oxide particle size range of 50 nm.

[0027] (2) Electroslag remelting slag system ratio: The electroslag remelting slag system was heated from room temperature to 950℃ and kept at that temperature for 5h. The chemical composition of the slag system by mass percentage included: CaF2: 52%, CaO: 32%, MgO: 1%, Al2O3: 5%, TiO2: 10%, and the remainder were unavoidable impurities; Slag system viscosity: 0.017 Pa·S at 1500℃ and 0.020 Pa·S at 1600℃.

[0028] (3) Current and voltage gradient control: The current and voltage during the electroslag remelting process are controlled in four stages, as follows: voltage 20V and current 1.6kA during the arc initiation period; voltage 25V and current 1.6kA during the slag formation period; voltage 30V and current 2.4kA during the remelting period; voltage 18V and current 2.0kA during the feeding period. (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The partial pressure of gas in the furnace is changed according to the current and voltage during the smelting process. The gas atmosphere control in the electroslag furnace is as follows: flow rate 260L / min during arc initiation, flow rate 260L / min during slag formation, 150L / min during remelting, 100L / min during feeding, and the total oxygen content of molten steel is stably controlled at 7ppm.

[0029] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling. Example 3

[0030] A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation includes the following steps: (1) Surface quality control of electrode ingots: The chemical composition of electrode ingots is controlled by mass percentage as follows: C: 0.22%, Si: 0.25%, Mn: 0.90%, Cr: 0.85%, Ni: 0.4%, Al: 0.055%, Nb: 0.030%, Mo: 0.15%, Ti: 0.08%, with the remainder being Fe and unavoidable impurities; An anti-oxidation coating is uniformly applied to the surface of the electrode ingots; The anti-oxidation coating is a nano-yttrium oxide dispersion-reinforced aluminate coating with a yttrium oxide content of 6%, a coating thickness of 0.2-0.5 mm, and a nano-yttrium oxide particle size range of 100 nm.

[0031] (2) Electroslag remelting slag system ratio: The electroslag remelting slag system was heated from room temperature to 1000℃ and kept at that temperature for 5h. The chemical composition of the slag system by mass percentage included: CaF2: 54%, CaO: 28%, MgO: 2%, Al2O3: 7%, TiO2: 9%, and the remainder were unavoidable impurities. The viscosity of the slag system was 0.020 Pa·S at 1500℃ and 0.025 Pa·S at 1600℃.

[0032] (3) Current and voltage gradient control: The current and voltage during the electroslag remelting process are controlled in four stages, as follows: voltage 22V and current 1.7kA during the arc initiation period; voltage 26V and current 2.0kA during the slag formation period; voltage 33V and current 2.5kA during the remelting period; voltage 19V and current 2.4kA during the feeding period. (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The partial pressure of gas in the furnace is changed with the current and voltage during the smelting process. The gas atmosphere in the electroslag furnace is controlled as follows: flow rate 240L / min during arc initiation, flow rate 240L / min during slag formation, 170L / min during remelting, 120L / min during feeding, and the total oxygen content of molten steel is stably controlled at 10ppm.

[0033] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling. Example 4

[0034] A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation includes the following steps: (1) Electrode ingot preparation and surface quality control: The chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.18%, Si: 0.19%, Mn: 0.85%, Cr: 0.95%, Ni: 0.45%, Al: 0.048%, Nb: 0.022%, Mo: 0.135%, Ti: 0.08%, with the remainder being Fe and unavoidable impurities; An anti-oxidation coating is uniformly applied to the surface of the electrode ingot; The anti-oxidation coating is a nano-yttrium oxide dispersion-reinforced aluminate coating with a yttrium oxide content of 5%, a coating thickness of 0.2~0.5 mm, and a nano-yttrium oxide particle size of 25 nm.

[0035] (2) Electroslag remelting slag system ratio: The electroslag remelting slag system was heated from room temperature to 980℃ and kept at that temperature for 4.5h; the chemical composition of the slag system (mass percentage): CaF2: 50%, CaO: 24%, MgO: 1.5%, Al2O3: 4%, TiO2: 8.5%, and the remainder were unavoidable impurities; the viscosity of the slag system was 0.016 Pa·S at 1500℃ and 0.019 Pa·S at 1600℃.

[0036] (3) Current and voltage gradient control: The current and voltage are dynamically controlled in four stages during the electroslag remelting process. The specific control is as follows: Arc initiation period: voltage 21V, current 1.65kA; Slag formation period: voltage 26V, current 1.8kA; Remelting period: voltage 31V, current 2.55kA; Compensation period: voltage 18.5V, current 2.2kA.

[0037] (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The partial pressure of gas in the furnace is changed according to the current and voltage during the smelting process. The gas atmosphere control in the electroslag furnace is as follows: flow rate 230L / min during arc initiation, flow rate 230L / min during slag formation, 160L / min during remelting, 110L / min during feeding, and the total oxygen content of molten steel is stably controlled at 9ppm.

[0038] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling. Example 5

[0039] A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation includes the following steps: (1) Electrode ingot preparation and surface quality control: The chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.20%, Si: 0.22%, Mn: 0.88%, Cr: 1.05%, Ni: 0.48%, Al: 0.052%, Nb: 0.028%, Mo: 0.145%, Ti: 0.08%, with the remainder being Fe and unavoidable impurities; An anti-oxidation coating is uniformly applied to the surface of the electrode ingot; A small amount of nano-yttrium oxide is added to the aluminate, with the yttrium oxide content being 8%, the coating thickness being 0.2~0.5mm, and the nano-yttrium oxide particle size being 75nm.

[0040] (2) Electroslag remelting slag system ratio: The electroslag remelting slag system was heated from room temperature to 960℃ and kept at that temperature for 4h; the chemical composition of the slag system (mass percentage): CaF2: 55%, CaO: 26%, MgO: 1.8%, Al2O3: 6%, TiO2: 9.5%, and the remainder were unavoidable impurities; the viscosity of the slag system was 0.018 Pa·S at 1500℃ and 0.022 Pa·S at 1600℃.

[0041] (3) Current and voltage gradient control: The current and voltage are dynamically controlled in four stages during the electroslag remelting process. The specific control is as follows: Arc initiation period: voltage 23V, current 1.75kA; Slag formation period: voltage 27V, current 2.2kA; Remelting period: voltage 34V, current 2.6kA; Compensation period: voltage 19.5V, current 2.5kA.

[0042] (4) Gas atmosphere control in electroslag furnace: Argon gas is used for protection throughout the process. The partial pressure of gas in the furnace is changed according to the current and voltage during the smelting process. The gas atmosphere control in the electroslag furnace is as follows: flow rate 250L / min during arc initiation, flow rate 250L / min during slag formation, 165L / min during remelting, 130L / min during feeding, and the total oxygen content of molten steel is stably controlled at 6ppm.

[0043] After cooling and demolding, the electroslag ingot is protected by a hood and argon gas until the temperature of the electroslag ingot is less than 400°C before being placed in a heating furnace for furnace cooling.

[0044] The oxygen content of the electroslag ingots in the comparative examples and embodiments was detected using an ON-851 oxygen-nitrogen analyzer. The Ti content of the initial electrode and the Ti content of the electroslag ingot were detected using a Spark8000 full-spectrum spark direct-reading spectrometer. The results are shown in Table 1. The type, size, and quantity of inclusions in the electroslag ingot were detected using an ASPEX automatic inclusion analysis electron microscope. The results are shown in Tables 2 and 3.

[0045] Table 1. Oxygen content and Ti yield during electroslag remelting

[0046] Table 2. Inclusions during electroslag remelting

[0047] Table 3. Inclusions during electroslag remelting

[0048] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for removing inclusions from ultrapure gear steel based on interface activation energy regulation, characterized in that, The method includes the following steps: (1) Surface quality control of electrode ingots: control the chemical composition of electrode ingots and apply an anti-oxidation coating; (2) Electroslag remelting slag system formulation and pretreatment: The electroslag remelting slag system is heated from room temperature to 900-1000℃ and kept at that temperature for 4-5 hours; a special slag system is prepared and baked. The chemical composition of the slag system includes: CaF2, CaO, MgO, Al2O 3、 TiO2; (3) Current-voltage gradient control: The current-voltage ratio is dynamically controlled in four stages during the electroslag remelting process; (4) Gas atmosphere control in electroslag furnace: Argon protection throughout the process and dynamic flow adjustment.

2. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to claim 1, characterized in that, The special slag system in step (2) contains the following chemical components by mass percentage: CaF2: 48-56%, CaO: 20-28%, MgO: 1-2%, Al2O3: 3-8%, TiO2: 8-10%.

3. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to claim 1, characterized in that, In step (2), the viscosity of the electroslag system at 1500℃ is 0.015~0.020 Pa·S, and the viscosity at 1600℃ is 0.018~0.025 Pa·S; the slag-gold interface activation energy between the slag system and the target inclusions (Al2O3, TiN) is adjusted to the optimal range, with the interface activation energy of Al2O3 being 120~150 kJ / mol and the interface activation energy of TiN being 150~180 kJ / mol.

4. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to claim 1, characterized in that, In step (3), the four-stage dynamic control is as follows: voltage 20-25V and current 1.6-1.8kA during the arc initiation period; voltage 25-28V and current 1.6-2.4kA during the slag formation period; voltage 30-35V and current 2.4-2.7kA during the remelting period; and voltage 18-20V and current 2.0-2.6kA during the shrinkage compensation period.

5. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to claim 1, characterized in that, In step (4), the dynamic argon flow rate is controlled as follows: 220-260 L / min during the arc initiation and slag formation periods, 150-180 L / min during the remelting period, and 100-150 L / min during the feeding period.

6. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to claim 1, characterized in that, The antioxidant coating in step (1) is a nano-yttrium oxide dispersion-reinforced aluminate coating with a coating thickness of 0.2 to 0.5 mm, a nano-yttrium oxide content of 4 to 9%, and a nano-yttrium oxide particle size range of 10 to 100 nm.

7. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to any one of claims 1-6, characterized in that, In step (1), the chemical composition of the electrode ingot is controlled by mass percentage as follows: C: 0.15-0.22%, Si: 0.15-0.25%, Mn: 0.65-0.95%, P≤0.0030%, S≤0.0020%, Cr: 0.85-1.15%, Ni: 0.40-0.5%, Al: 0.015-0.055%, Nb: 0.015-0.030%, Mo: 0.11-0.15%, with the remainder being Fe and unavoidable impurities.

8. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to any one of claims 1-6, characterized in that, The method yields ultrapure gear steel electroslag ingots with an inclusion number density of ≤4.06 inclusions / mm². 2 The number of inclusions was reduced by more than 30%; the TiN number density of electroslag ingots was ≤2.1 inclusions / mm. 2 The TiN removal rate exceeds 40%.

9. The method for removing inclusions from ultrapure gear steel based on interface activation energy regulation according to any one of claims 1-6, characterized in that, The method described above maintains a stable oxygen content of less than 10 ppm in molten steel and achieves a titanium recovery rate of over 92%.

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