Silicon steel smelting method and silicon steel

Abstract

The present application discloses a smelting method for silicon steel and silicon steel, the method comprising: providing molten iron to be smelted, wherein the silicon content in the molten iron to be smelted is 0.2%-0.8%, and the titanium content is ≤0.20%; subjecting the molten iron to be smelted to a converter to obtain converter molten steel, wherein corundum particles are added to the ladle after the converter smelting; and subjecting the converter molten steel to RH refining and continuous casting to obtain silicon steel.

Description

Technical Field

[0001] The present application belongs to the technical field of steel smelting, and specifically relates to a smelting method of silicon steel and silicon steel. Background Art

[0002] Silicon steel generally has excellent magnetic properties and is primarily used in power systems to achieve efficient electromagnetic conversion. It is primarily used to manufacture the cores of motors and transformers. Its excellent soft magnetic characteristics and magnetization properties provide high magnetic flux for transformers, thereby achieving efficient electric-magnetic-electrical conversion.

[0003] Titanium is a harmful element in silicon steel. Inclusions in silicon steel can pin grain boundaries, delay recrystallization, and hinder grain growth, thereby affecting the magnetic properties of silicon steel. In particular, some fine precipitates such as Ti(CN), MnS, and AlN, which precipitate during solidification and hot rolling, can strongly pin magnetic domains and deteriorate the magnetic properties of silicon steel.

[0004] The titanium in silicon steel primarily comes from molten iron, ladle slag, and alloys. To control the titanium content in finished silicon steel, current methods include limiting the titanium content of the incoming molten iron, reducing the titanium content in the slag through double-slag smelting in the converter (BOF), reducing the amount of slag discharged from the converter, and using low-titanium alloys. For example, some steel mills require a titanium content of less than 0.03% in molten iron, which significantly increases molten iron costs and hinders the use of high-titanium iron ore for blast furnace protection. Double-slag smelting in the converter not only reduces production efficiency and increases slag consumption, but also lowers alloy yield. Reducing the amount of slag discharged from the converter not only increases operational complexity but also reduces steel yield. Using low-titanium alloys significantly increases costs. Summary of the Invention

[0005] In view of this, the present application provides a smelting method of silicon steel and silicon steel, aiming to provide a smelting method of silicon steel and silicon steel that can be produced in a process-based manner, with simple operation and stable production of silicon steel with a low titanium content.

[0006] In a first aspect, an embodiment of the present application provides a method for smelting silicon steel, the method comprising:

[0007] Providing molten iron to be smelted, wherein the silicon content in the molten iron to be smelted is 0.2%-0.8%, and the titanium content is ≤0.20%;

[0008] The molten iron to be smelted is subjected to converter smelting to obtain converter steel, and the surface of the converter steel has slag. Corundum particles are added to the ladle after the converter smelting, and the density of the converter steel ρ1, the corundum particles ρ2, and the slag ρ3 satisfy the following relationship: ρ1<ρ2<ρ3;

[0009] The converter molten steel is subjected to RH refining and continuous casting to produce silicon steel.

[0010] According to an embodiment of one aspect of the present application, the molten iron to be smelted includes the following chemical components in mass percentage: C: 3.4%-4.1%, Si: 0.2%-0.8%, Mn: 0.08%-0.50%, P: 0.02%-0.1%, S: 0.02%-0.07%, Ti≤0.03%-0.20%, V: 0.004%-0.050%.

[0011] According to an embodiment of one aspect of the present application, the bottom blowing intensity during the converter smelting process is 3.4-4.0Nm 3 / min·t, the oxygen content of the final molten steel in the converter is 0.05-0.11%.

[0012] According to an embodiment of one aspect of the present application, the corundum particles meet at least one of the following conditions:

[0013] 1) The corundum particles include the following components in mass percentage: more than 80% of Al2O3 and inevitable impurity components.

[0014] 2) The particle size of corundum particles is 0.5-6mm;

[0015] 3) The amount of corundum particles added is 0.5-1.5kg / ton of steel;

[0016] 4) The density of corundum particles is 3.98-4.1g / cm 3 .

[0017] According to an embodiment of one aspect of the present application, converter smelting satisfies at least one of the following conditions:

[0018] 1) The density of the steel slag is 2.3-2.8 g / cm 3 ;

[0019] 2) The steel slag comprises the following components by mass percentage: CaO, 32%-48%; SIO2, 10%-20%; P2O5, 1.5%-3%; Al2O3, 3.5%-5%; MgO, 5%-6.5%; MnO, 3.5%-5%; Fe, 15%-35%, with the remainder being unavoidable impurities;

[0020] 3) performing KR desulfurization on the molten iron to obtain the molten iron to be smelted;

[0021] 4) The density of the converter molten steel is 6.5-7.6 g / cm 3 .

[0022] According to an embodiment of one aspect of the present application, the method satisfies at least one of the following conditions:

[0023] 1) The density of the molten steel in the RH refining is 6.5-7.6 g / cm 3 ;

[0024] 2) The density of the surface slag in the RH refining is 2.3-2.8 g / cm 3 ;

[0025] 3) The surface slag in the RH refining comprises the following components in mass percentage: CaO, 20%-40%; SIO2, 20%-32%; P2O5, 1.5%-3%; Al2O3≤0.4%; MgO, 7%-10%; MnO≤3%; Fe, 1.5%-3%, and the balance being unavoidable impurities.

[0026] According to an embodiment of one aspect of the present application, the titanium content of the converter molten steel when it is sampled for oxygen determination and temperature measurement at the argon station is 0.0002%-0.0004%.

[0027] According to an embodiment of one aspect of the present application, the titanium content of the molten steel in RH refining is ≤20 ppm.

[0028] In a second aspect, an embodiment of the present application provides a silicon steel produced by the smelting method of the first aspect.

[0029] According to an embodiment of one aspect of the present application, the chemical composition in silicon steel includes, in mass percentage: C: 0.001%-0.07%, Si: 0.9%-3.5%, Mn: 0.08%-0.7%, P: 0.005%-0.03%, S: ≤0.010%, Als: 0.01%-0.6%, V: ≤0.0030%, Ti≤0.0030%.

[0030] This application has at least the following beneficial effects:

[0031] 1) The smelting method provided by the present application does not require the use of only low-titanium molten iron, thus meeting the needs of blast furnace production and avoiding the cost of the process of pre-de-titaniumization of molten iron.

[0032] 2) The smelting method provided in the present application does not require converter double slag smelting during the converter smelting process, thereby improving production efficiency and avoiding the reduction in molten steel yield caused by reducing slag feeding.

[0033] 3) The smelting method provided in the present application does not limit the amount of ladle slag and the titanium content in the slag during the converter smelting process, and corundum particles are added during the converter smelting (for example, during the steel tapping process). The density of the corundum particles is between that of the molten steel (molten iron) and the ladle slag, so that the corundum particles are located between the molten steel and the slag, forming a particle layer, which plays an isolating role, preventing the titanium in the slag from being reduced into the molten steel, increasing the titanium content in the steel, and affecting the performance of the silicon steel.

[0034] 4) The smelting method provided by the present application can stably control the residual titanium content in Rh molten steel / molten steel for continuous casting to be within 20 ppm, and can reach a minimum of 6 ppm, meeting the titanium content requirement of silicon steel production for molten steel, which is lower than 0.003%. DETAILED DESCRIPTION

[0035] In order to make the application purpose, technical solutions and beneficial technical effects of this application clearer, the application is further described in detail below with reference to the embodiments. It should be understood that the implementation regulations described in this specification are only for the purpose of explaining this application and are not intended to limit this application.

[0036] For simplicity, this application only explicitly discloses certain numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and similarly, any upper limit can be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value can serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0037] In the description of this application, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number, and “a variety” in “one or more” means two or more.

[0038] The above disclosure of the present application is not intended to describe every disclosed embodiment or every implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of examples, and these implementation regulations can be used in various combinations. In each example, the enumeration is only intended to be representative and should not be construed as exhaustive.

[0039] Ti is a harmful element in silicon steel. Inclusions in silicon steel can pin grain boundaries, delay recrystallization, and hinder grain growth, thereby affecting the magnetic properties of silicon steel. In particular, some fine precipitates such as Ti(CN), MnS, and AlN, which precipitate during solidification and hot rolling, can strongly pin magnetic domains and affect the magnetic properties of silicon steel.

[0040] Titanium is not suitable as an inhibitor for grain-oriented silicon steel because it forms TiN, which is more stable than BN and AlN. During hot rolling and normalizing, TiN can serve as a nucleus for AlN and MnS precipitation, forming coarse composite precipitates. TiS also causes uneven nitrogen diffusion and imperfect secondary recrystallization. Grain-oriented silicon steel generally requires a Ti content of ≤ 0.0020%.

[0041] The titanium content of silicon steel primarily comes from molten iron, ladle slag, and alloys. To control the titanium content in finished silicon steel, current methods include limiting the titanium content of the incoming molten iron, reducing the titanium content in the slag through double-slag smelting in the converter (BOF), reducing the amount of slag discharged from the converter, and using low-titanium alloys. For example, some steel mills require a molten iron titanium content of less than 0.03%. This significantly increases molten iron costs and hinders the use of high-titanium iron ore for blast furnace protection. Double-slag smelting in the converter not only reduces production efficiency and increases slag consumption, but also reduces alloy yield. Reducing the amount of slag discharged from the converter not only increases operational complexity but also reduces steel yield. Using low-titanium alloys significantly increases costs.

[0042] The related technology can only reduce the titanium addition in molten steel by reducing the amount of ladle slag or reducing the titanium content in the ladle slag, and the related technology cannot solve the problem of titanium in the ladle slag being reduced and entering the molten steel.

[0043] In view of this, the present application provides a method for smelting silicon steel, so as to provide a new smelting method without changing the original process, so as to produce silicon steel with a lower titanium content.

[0044] Silicon steel smelting method

[0045] In a first aspect, an embodiment of the present application provides a method for smelting silicon steel, the method comprising:

[0046] Providing molten iron to be smelted, wherein the silicon content in the molten iron to be smelted is 0.2-0.8%, and the titanium content is ≤0.20%;

[0047] The molten iron to be smelted is subjected to converter smelting to obtain converter molten steel, wherein the surface of the converter molten steel has slag, corundum particles are added to the ladle after the converter smelting, and the density ρ1 of the converter molten steel, the corundum particles ρ2, and the density ρ3 of the slag satisfy the following relationship: ρ1<ρ2<ρ3;

[0048] The converter molten steel is subjected to RH refining and continuous casting to produce silicon steel.

[0049] In some embodiments, the alloy is added to the ladle after smelting in the converter, and the amount of the alloy added is 15-60 kg / ton of steel.

[0050] In the related art, the main sources of titanium entering the molten steel are ladle slag and alloys, with ladle slag being the main source. Titanium is an element that is easily oxidized. After the molten iron is blown in a converter, the titanium element in the molten iron combines with oxygen to form titanium oxide, which floats up into the converter slag. During the tapping process, the slag enters the ladle along with the swirling flow of the molten steel at the end of the tapping process. In the subsequent production process, large amounts of ferrosilicon and aluminum are added to the ladle to deoxidize and alloy the molten steel. The titanium oxide and other substances in the slag will also be reduced and enter the molten steel in the form of metal. The titanium content in the slag and the total amount of ladle slag will affect the amount of titanium entering the molten steel.

[0051] In order to control the Ti content in silicon steel, corundum particles are added at the end of converter smelting. The addition time can be during the tapping process of converter smelting and in the ladle before RH smelting. At this time, the temperature of the molten steel is 1590-1650℃.

[0052] By adopting the method of the embodiment of the present application, the titanium content in the molten steel at the end of converter smelting can be reduced to a low level, such as 0.0001%.

[0053] According to the embodiments of the present application, the titanium content in the molten iron to be smelted is within the above range, and there is no need to strictly control the titanium content in the molten iron to a particularly low content, which not only meets the needs of blast furnace production but also avoids the process cost of pre-de-titaniumization of the molten iron.

[0054] According to the embodiment of the present application, the corundum particles are an oxide mineral whose main component is Al2O3, has stable chemical properties, a melting point of 2000-2030°C, and does not chemically react with molten steel.

[0055] According to the method of the embodiment of the present application, there is no need to impose strict requirements on the titanium content range of the molten iron to be smelted, which not only meets the need for titanium nitride furnace protection for blast furnace production, but also avoids the process cost of pre-de-titaniumization of the molten iron. There is also no need to reduce the titanium content in the slag through double slag smelting or reduce the amount of ladle slag.

[0056] In some embodiments, the corundum particles are added during the tapping process of the molten steel in the converter.

[0057] According to an embodiment of the present application, during the converter smelting process, corundum particles are added during the steel tapping process to form a corundum layer, which is located between the molten steel and the slag on the surface of the molten steel, playing an isolation role and preventing the titanium in the slag from being reduced into the molten steel.

[0058] In some optional embodiments, the molten iron to be smelted includes the following chemical components in mass percentage: C: 3.4%-4.1%, Si: 0.2%-0.8%, Mn: 0.08%-0.50%, P: 0.02%-0.1%, S: 0.02%-0.07%, Ti≤0.03%-0.20%, V: 0.004%-0.050%.

[0059] In some optional embodiments, the bottom blowing intensity during the converter smelting process is 3.4-4.0 Nm 3 / min·t, the oxygen content of the final molten steel in the converter is 0.05-0.11%.

[0060] Bottom blowing intensity refers to the volume of stirring gas introduced per ton of molten steel per minute.

[0061] According to the embodiment of the present application, by controlling the bottom blowing intensity during the converter smelting process within the above range, it can be used to adjust the composition of the molten steel, especially the oxygen content. By increasing the bottom blowing intensity, the oxygen supply can be increased, prompting unnecessary elements such as silicon and manganese to be oxidized and removed. This helps to control the impurity content in the steel, and increasing the bottom blowing intensity of the steel can also be used to adjust the carbon content in the steel. By controlling the flow rate and distribution of the bottom-blown oxygen, the degree of carbon oxidation can be adjusted, thereby changing the carbon content of the steel to meet specific product requirements. Bottom blowing intensity is also important for controlling the formation and removal of slag. Appropriate bottom blowing intensity can promote the formation and removal of slag, and can also avoid the contact between the steel slag and the molten steel, resulting in a low titanium content in the molten steel, prevent the slag from mixing into the steel, and improve the quality of the steel.

[0062] In some optional embodiments, the corundum particles meet at least one of the following conditions:

[0063] 1) The corundum particles include the following components in mass percentage: more than 80% of Al2O3 and inevitable impurity components.

[0064] 2) The particle size of corundum particles is 0.5-6mm;

[0065] 3) The amount of corundum particles added is 0.5-1.5kg / ton of steel;

[0066] 4) The density of corundum particles is 3.98-4.1g / cm 3 .

[0067] According to an embodiment of the present application, the corundum particles with the above characteristics are transferred from the converter molten steel to the RH furnace, forming a protective layer. On the one hand, a slag skin can be formed on the surface of the molten steel, reducing the contact between the molten steel and the air, thereby reducing the oxidation reaction. This helps to protect the alloying elements in the molten steel and reduce the loss of elements. It can also help control the temperature of the molten steel, slow down the cooling rate of the molten steel, and help maintain a suitable furnace temperature to ensure that the reaction in the furnace can continue while preventing unnecessary temperature drops. It can also intercept and adsorb some impurities and inclusions on the surface of the molten steel, thereby purifying the molten steel. This helps to improve the quality of the steel and reduce the content of internal inclusions. In addition, the loss of alloying elements can be reduced, the recovery rate of alloying elements in the molten steel can be improved, and it is beneficial to reduce costs.

[0068] In some optional embodiments, converter smelting satisfies at least one of the following conditions:

[0069] 1) The density of the steel slag is 2.3-2.8 g / cm 3 ;

[0070] 2) The steel slag comprises the following components by mass percentage: CaO, 32%-48%; SIO2, 10%-20%; P2O5, 1.5%-3%; Al2O3, 3.5%-5%; MgO, 5%-6.5%; MnO, 3.5%-5%; Fe, 15%-35%, with the remainder being unavoidable impurities;

[0071] 3) performing KR desulfurization on the molten iron to obtain the molten iron to be smelted;

[0072] 4) The density of the converter molten steel is 6.5-7.6 g / cm 3 .

[0073] According to the embodiments of the present application, the steel slag contains the aforementioned components and has the aforementioned density, which can protect molten steel from oxidation and significantly improve steel properties, such as hardness, strength, toughness, and corrosion resistance. Furthermore, it can help optimize smelting process control, ensure stable production, reduce adverse smelting reactions, and thus improve production efficiency.

[0074] According to the embodiments of the present application, steel slag can react with impurities and inclusions generated during the smelting process, separating them from the steel. This helps improve the quality of the steel and reduce the inclusion content. The formation of steel slag can help control the temperature during the smelting process. Appropriate steel slag can help maintain the chemical balance in the furnace, reduce unnecessary reactions and oxidation, and thus improve the stability of the smelting process. The appropriate amount of steel slag can form an isolation layer, forming a double isolation layer together with the corundum, preventing the steel slag from mixing into the molten steel and improving the quality of the steel.

[0075] In some optional embodiments, the method satisfies at least one of the following conditions:

[0076] 1) The density of the molten steel in the RH refining is 6.5-7.6 g / cm 3 ;

[0077] 2) The density of the surface slag in the RH refining is 2.3-2.8 g / cm 3 ;

[0078] 3) The surface slag in the RH refining comprises the following components in mass percentage: CaO, 20%-40%; SIO2, 20%-32%; P2O5, 1.5%-3%; Al2O3≤0.4%; MgO, 7%-10%; MnO≤3%; Fe, 1.5%-3%, and the balance being unavoidable impurities.

[0079] According to the embodiment of the present application, the above-mentioned KR desulfurization method can be used to obtain molten iron to be smelted with a sulfur content within an appropriate range.

[0080] According to the embodiment of the present application, by controlling the density of the converter molten steel and the density of the slag and corundum

[0081] In some optional embodiments, the titanium content of the converter molten steel when it is sampled for oxygen determination and temperature measurement at the argon station is 0.0002%-0.0004%.

[0082] In some optional embodiments, the titanium content of the molten steel in RH refining is ≤20 ppm.

[0083] In a second aspect, an embodiment of the present application provides a silicon steel produced by the smelting method of the first aspect.

[0084] In some optional embodiments, the chemical composition of the silicon steel includes, in mass percentage: C: 0.001%-0.07%, Si: 0.9%-3.5%, Mn: 0.08%-0.7%, P: 0.005%-0.03%, S: ≤0.010%, Als: 0.01%-0.6%, V: ≤0.0030%, Ti≤0.0030%.

[0085] Example

[0086] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and all instruments used in the examples are commercially available.

[0087] Example 1

[0088] A method for smelting silicon steel, comprising:

[0089] Hot metal desulfurization: Hot metal is used for desulfurization, and the titanium content of the hot metal is 0.16%. After desulfurization, the hot metal to be smelted includes the following chemical components in mass percentage: C: 3.8%, Si: 0.43%, Mn: 0.29%, P: 0.075%, S: 0.0006%, Ti: 0.16%, V: 0.0089%.

[0090] Converter smelting: The above molten iron is smelted in a converter, and the bottom blowing strength is guaranteed to be 3.9Nm during the blowing process. 3 / min·t, and the oxygen content of the molten steel at the end of smelting is 0.076%. Corundum particles with a particle size of 0.5-6mm are added during the tapping process, and the addition amount is 1.0kg / ton of steel. Corundum particles are added to the ladle, which is between the molten iron and the slag in the converter. Alloys and top slag are added as needed for modification. The converter tapping is carried out by slag blocking, and the slag blocking cone is used in conjunction with the slide plate slag blocking. After tapping, the ladle car is driven to the argon station for oxygen determination, temperature measurement and sampling, and then transported to the RH furnace. The titanium content in the molten steel is 0.0002%.

[0091] RH refining: According to the requirements of steel grade, refining such as composition adjustment and temperature adjustment is carried out in the RH furnace.

[0092] Continuous casting: After the composition temperature is qualified, the upper continuous casting is carried out, and the titanium content in the molten steel in the tundish is 0.0013%.

[0093] Example 2

[0094] A method for smelting silicon steel, comprising:

[0095] Hot metal desulfurization: Hot metal is used for desulfurization, and the titanium content of the hot metal is 0.13%. After desulfurization, the hot metal to be smelted includes the following chemical components in mass percentage: C: 4.0%, Si: 0.23%, Mn: 0.33%, P: 0.065%, S: 0.0007%, Ti: 0.13%, V: 0.0104%.

[0096] Converter smelting: The above molten iron is smelted in a converter, and the bottom blowing strength is guaranteed to be 4.0Nm during the blowing process. 3 / min·t, with an oxygen content of 0.082% at the end of smelting. Corundum particles with a particle size of 0.5-6mm are added during tapping at a rate of 0.7kg / ton of steel. Alloys and top slag are added as needed for modification. BOF tapping is performed with slag blocking, using a slag blocking cone and slide plate. After tapping, the ladle car is driven to an argon station for oxygen measurement, temperature measurement, and sampling before transfer to the RH furnace. The titanium content in the molten steel is 0.0003%.

[0097] RH refining: According to the requirements of steel grade, refining such as composition adjustment and temperature adjustment is carried out in the RH furnace.

[0098] Continuous casting: After the composition temperature is qualified, the upper continuous casting is carried out, and the titanium content in the molten steel in the tundish is 0.0016%.

[0099] Example 3

[0100] A method for smelting silicon steel, comprising:

[0101] Hot metal desulfurization: Hot metal is used for desulfurization. The titanium content of the hot metal is 0.07%. After desulfurization, the hot metal to be smelted includes the following chemical composition by mass percentage: Si: 0.33%, Mn: 0.29%, P: 0.055%, S: 0.0006%, Ti: 0.07%, V: 0.0083%. Converter smelting: The above hot metal is subjected to converter smelting. The bottom blowing strength during the blowing process is guaranteed to be 3.6Nm 3 / min·t, with an oxygen content of 0.082% at the end of smelting. Corundum particles with a particle size of 0.5-6mm are added during tapping at a rate of 1.5kg / ton of steel. Alloys and top slag are added as needed for modification. BOF tapping is performed with slag blocking, using a slag blocking cone and slide plate. After tapping, the ladle car is driven to an argon station for oxygen measurement, temperature measurement, and sampling before transfer to the RH furnace. The titanium content in the molten steel is 0.0002%.

[0102] RH refining: According to the requirements of steel grade, refining such as composition adjustment and temperature adjustment is carried out in the RH furnace.

[0103] Continuous casting: After the composition temperature is qualified, the upper continuous casting is carried out, and the titanium content in the molten steel in the tundish is 0.0007%.

[0104] Comparative Example 1

[0105] The present application is different from Example 1 in that no corundum particles are added.

[0106] Test section

[0107] The bimetallic band saw blades prepared in the examples and comparative examples were sampled according to GB / T 2975 “Sampling location and specimen preparation for mechanical properties testing of steel and steel products”.

[0108] (1) Silicon steel composition detection: The titanium content of the silicon steel in the embodiment and the comparative example was determined by direct reading spectrometer according to the method of GB / T 4336-2016. The titanium content of the silicon steel in the embodiment and the comparative example was determined by the instrument, as shown in Table 1.

[0109] (2) Mechanical properties testing:

[0110] According to GB / T228.1-2010 "Tension test of metallic materials Part 1 Room temperature test method", the bimetallic band saw blades prepared in the examples and comparative examples were sampled. The test results of the samples are shown in Table 1.

[0111] The tensile test was carried out using a German Zwick tensile testing machine with a load range of 50 to 1500 kN and a displacement speed of 2 mm / min. The tensile strength, yield limit, elongation and other test data of the material were obtained by computer graphics. The test results are shown in Table 1.

[0112] (3) Inclusion detection: After taking a sample of a certain size and polishing the cross-section in the rolling direction and the thickness direction, the number of inclusions in a certain area and the composition of each inclusion are measured using the automatic inclusion counting function of a scanning electron microscope. The number of inclusions per unit area or the number of inclusions containing a certain element per unit area is calculated to achieve the determination of the titanium inclusion content of the silicon steel in the examples and comparative examples.

[0113] Table 1 Titanium content and mechanical properties of silicon steel in Example

[0114]

[0115] Table 2

[0116]

[0117] In summary, it is shown that the method of application is beneficial to controlling the titanium content of RH refined molten steel and silicon steel, and is beneficial to reducing the number of titanium inclusions in oriented silicon steel.

[0118] The above is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any modification or replacement of the present technology should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for smelting silicon steel, characterized in that: The method comprises: Providing molten iron to be smelted, wherein the silicon content in the molten iron to be smelted is 0.2%-0.8%, and the titanium content is ≤0.20%; The molten iron to be smelted is subjected to converter smelting to obtain converter molten steel, wherein the surface of the converter molten steel has steel slag, and corundum particles are added to the ladle after the converter smelting, wherein the density ρ1 of the converter molten steel, the density ρ2 of the corundum particles, and the density ρ3 of the steel slag satisfy the following relationship: ρ1<ρ2<ρ3; the particle size of the corundum particles is 0.5-6 mm; and the amount of the corundum particles added is 0.5-1.5 kg / ton of steel; The converter molten steel is subjected to RH refining and continuous casting to produce the silicon steel.

2. The smelting method according to claim 1, characterized in that: The molten steel to be smelted includes the following chemical components in mass percentage: C: 3.4%-4.1%, Si: 0.2%-0.8%, Mn: 0.08%-0.50%, P: 0.02%-0.1%, S: 0.02%-0.07%, Ti: 0.03%-0.20%, V: 0.004%-0.050%.

3. The smelting method according to claim 1, characterized in that: The bottom blowing intensity during the converter smelting process is 3.4-4.0Nm 3 / min•t, and the oxygen content of the final molten steel in the converter smelting is 0.05%-0.11%.

4. The smelting method according to claim 1 or 3, characterized in that: The corundum particles meet at least one of the following conditions: 1) The corundum particles include the following components by mass percentage: more than 80% of Al2O3 and inevitable impurities; 2) The density of the corundum particles is 3.98-4.1 g / cm³.

5. The smelting method according to claim 1, characterized in that: The converter smelting satisfies at least one of the following conditions: 1) The density of the steel slag is 2.3-2.8g / cm³; 2) The steel slag comprises the following components by mass percentage: CaO, 32%-48%; SIO2, 10%-20%; P2O5, 1.5%-3%; Al2O3, 3.5%-5%; MgO, 5%-6.5%; MnO, 3.5%-5%; Fe, 15%-35%, with the remainder being unavoidable impurities; 3) performing KR desulfurization on the molten iron to obtain the molten iron to be smelted; 4) The density of the converter molten steel is 6.5-7.6 g / cm³.

6. The smelting method according to claim 1, characterized in that: The method satisfies at least one of the following conditions: 1) The density of the molten steel in the RH refining is 6.5-7.6 g / cm³; 2) The density of the surface slag in the RH refining is 2.3-2.8 g / cm³; 3) The surface slag in the RH refining comprises the following components by mass percentage: CaO, 20%-40%; SIO2, 20%-32%; P2O5, 1.5%-3%; Al2O3≤0.4%; MgO, 7%-10%; MnO≤3%; Fe, 1.5%-3%, and the balance being unavoidable impurities.

7. The smelting method according to claim 1, characterized in that: The titanium content of the converter molten steel when it is sampled for oxygen determination and temperature measurement at the argon station is 0.0002%-0.0004%.

8. The smelting method according to claim 1, characterized in that: The titanium content of the molten steel in the RH refining is ≤20 ppm.

9. A silicon steel, characterized in that: It is prepared by the smelting method according to any one of claims 1 to 8.

10. The silicon steel according to claim 9, characterized in that The chemical composition of the silicon steel includes, by mass percentage, C: 0.001%-0.07%, Si: 0.9%-3.5%, Mn: 0.08%-0.7%, P: 0.005%-0.03%, S: ≤0.010%, Als: 0.01%-0.6%, V: ≤0.0030%, and Ti≤0.0030%.

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