Preparation method of oriented silicon steel and oriented silicon steel

Abstract

The method comprises the steps that molten iron with the titanium mass content smaller than or equal to 0.25% is subjected to converter smelting, converter molten steel is prepared and transferred to a steel ladle, and the oxygen content of the converter molten steel at the end point of converter smelting is 0.06%-0.09%; aluminum blocks, 43.2-48kg of silicon iron per ton of molten steel and 0-4kg of phosphorus iron alloy per ton of molten steel are added in the process of transferring the molten steel of the converter to a steel ladle; the converter molten steel is subjected to RH vacuum refining, refined molten steel is prepared, and the adding amount of silicon iron is 0-4.8 kg per ton of steel in the RH vacuum refining process; the adding amount of the temperature-adjusting scrap steel is 0-2 kg per ton of steel; and the refined molten steel is subjected to continuous casting to prepare the oriented silicon steel, and the oriented silicon steel comprises the following chemical components in percentage by mass: 0.03%-0.07% of C, 3.0%-3.50% of Si, 0.1%-0.3% of Mn, 0.01%-0.035% of P, less than or equal to 0.0100% of S, 0.01%-0.035% of Als, less than or equal to 0.0030% of Ti, less than or equal to 0.002% of T.O and the balance of Fe and inevitable impurity elements. According to the preparation method, the titanium content of the oriented silicon steel is reduced, so that the oriented silicon steel has excellent magnetic performance and relatively low iron loss.

Description

Technical Field

[0001] This application belongs to the technical field of the preparation of grain-oriented electrical steel, and specifically relates to a preparation method of grain-oriented electrical steel and grain-oriented electrical steel. Background Art

[0002] As a core representative of iron-based soft magnetic materials, grain-oriented electrical steel is widely used in the fields of power transformers, motors, and electromagnetic equipment due to its excellent magnetic permeability (μ≥10 4 H / cm) and low coercivity (Hc≤5 A / m). However, its high performance is in sharp contradiction with the high sensitivity of the preparation process, which has become a key bottleneck restricting industrial upgrading.

[0003] The current mainstream production process adopts "converter smelting - refining - continuous casting", and the core difficulties lie in the regulation of titanium element and the control dilemma of grain size. Summary of the Invention

[0004] In view of this, this application provides a preparation method of grain-oriented electrical steel and grain-oriented electrical steel. On the basis of not affecting the mechanical properties of grain-oriented electrical steel, this preparation method reduces the titanium content in the steel, improves the excellent magnetic properties of grain-oriented electrical steel, and reduces the iron loss of grain-oriented electrical steel.

[0005] In the first aspect, an embodiment of this application provides a preparation method of grain-oriented electrical steel, including:

[0006] Carry out converter smelting on hot metal with a titanium mass content ≤0.25% to obtain converter molten steel and transfer the converter molten steel to a ladle. Among them, the oxygen content of the converter molten steel at the end of converter smelting is 0.06% to 0.09%; during the process of transferring the converter molten steel to the ladle, add aluminum blocks, 43.2 - 48 kg / ton of molten steel of ferrosilicon, and 0 - 4 kg / ton of molten steel of ferrophosphorus alloy;

[0007] Carry out RH vacuum refining on the converter molten steel to obtain refined molten steel. Among them, during the RH vacuum refining process, the addition amount of ferrosilicon is 0 - 4.8 kg / ton of molten steel to make the addition amount of ferrosilicon 48 kg / ton of molten steel; the addition amount of temperature-adjusting scrap steel is 0 - 2 kg / ton of molten steel;

[0008] Carry out continuous casting on the refined molten steel to obtain grain-oriented electrical steel. Among them, the grain-oriented electrical steel includes the following chemical components by mass percentage: C: 0.03% - 0.07%, Si: 3.0% - 3.50%, Mn: 0.1% - 0.3%, P: 0.01% - 0.035%, S≤0.0100%, Als: 0.01% - 0.035%, Ti≤0.0030%, T.O≤0.002%, and the balance is Fe and inevitable impurity elements.

[0009] In some alternative embodiments, the mass content of titanium in the ferrosilicon is ≤0.015%.

[0010] In some alternative embodiments, the ferrophosphorus alloy comprises, by mass percentage, 23%-25% of phosphorus element, 70%-73% of iron element, ≤0.5% of titanium element and inevitable impurity elements.

[0011] In some alternative embodiments, the calculation method of the addition amount of the aluminum block is: the addition amount of the aluminum block (kg) = (ω[O] - 0.0020%) × 1000 × 1.125 kg / ton of molten steel, where ω[O] represents the oxygen content of the molten steel in the converter at the end of the converter blowing.

[0012] In some alternative embodiments, the temperature-adjusting scrap steel comprises, by mass percentage, 96%-97% of iron element, 3%-3.5% of silicon element, ≤0.0030% of titanium element and inevitable impurity elements.

[0013] In some alternative embodiments, the phosphorus element content in the refined molten steel is 0.025% to 0.035%.

[0014] In some alternative embodiments, after the hot metal with a titanium mass content of ≤0.25% is subjected to converter smelting to obtain converter molten steel and the converter molten steel is transferred to a ladle, the method further comprises: by adding an Al2O3 slag material operation, making the mass content of Al2O3 in the ladle slag reach 43%-55%.

[0015] In some alternative embodiments, the ladle slag comprises, by mass percentage, CaO: 17%-19%, SiO 2: 19%-21%, Al2O 3: 43%-55%, MgO: 6%-9% and the rest are inevitable impurity components.

[0016] In some alternative embodiments, after the refined molten steel is continuously cast, the method further comprises:

[0017] The slab prepared by continuous casting is hot-rolled, and the hot-rolled slab is normalized, cold-rolled, decarburized and annealed,

[0018] coated with magnesium oxide, high-temperature annealed, flat stretched annealed and coated with an insulating film to obtain grain-oriented silicon steel,

[0019] In a second aspect, an embodiment of the present application provides a grain-oriented silicon steel prepared by the method of the first aspect.

[0020] In some alternative embodiments, the iron loss P of the grain-oriented silicon steel 17 / 50 is 0.71-0.85 W / kg, and the magnetic induction intensity B8 is 1.89-1.94 T.

[0021] This application has at least the following beneficial effects:

[0022] The method provided by this application controls the raw material components, addition amounts, and titanium input amounts during the steelmaking process, controls the appropriate alloy addition amount and the oxygen content at the end of the converter during the converter smelting process, combines with the process of optimizing the addition amount of temperature-adjusting scrap steel and the composition of the ladle slag in the RH vacuum refining, further stably controls the titanium content in the grain-oriented electrical steel at a low level, improves the magnetic properties of the grain-oriented electrical steel, and reduces the iron loss. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions of the embodiments of this application, the drawings required to be used in the embodiments of this application will be briefly introduced below. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Shows the influence of the oxygen content of the molten steel in the embodiment of this application on the titanium input rate in ferrosilicon.

[0025] Figure 2 Shows the effect diagram of the influence of the temperature-adjusting scrap steel of this application on the titanium increment of the molten steel.

[0026] Figure 3 Shows the influence of the ladle slag components in the embodiment of this application on the titanium content in the molten steel.

[0027] Figure 4 Shows the curve graph of the change in the titanium content in the molten steel of the embodiment and the comparative example of this application. Detailed Embodiments

[0028] In order to make the application purpose, technical solutions, and beneficial technical effects of this application clearer, the following further details this application in combination with embodiments. It should be understood that the embodiments described in this specification are only for explaining this application and not for limiting this application.

[0029] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly recorded; and any lower limit can be combined with other lower limits to form a range not explicitly recorded. Similarly, any upper limit can be combined with any other upper limit to form a range not explicitly recorded. In addition, although not explicitly recorded, each point or single value between the range endpoints is included in this range. Thus, each point or single value can be used as its own lower limit or upper limit and combined with any other point or single value or combined with other lower limits or upper limits to form a range not explicitly recorded.

[0030] In the description of the present application, it should be noted that unless otherwise specified, "above" and "below" include the corresponding numerical value, and the meaning of "multiple" in "one or more" is two or more than two.

[0031] The above application content of the present application does not intend to describe every disclosed embodiment or every implementation mode in the present application. The following description more specifically gives examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments, and these embodiments can be used in various combinations. In each instance, the enumeration is only a representative group and should not be construed as exhaustive.

[0032] [Ti] in grain-oriented silicon steel will form fine inclusions TiO x and nano-scale inclusions such as Ti(N,C) (particle size < 50nm), which not only hinder the full removal of carbon element (residual carbon content needs to be < 0.003%), but also reduce the cleanliness of molten steel, inhibit grain growth during annealing, are not conducive to the formation of Goss texture, and thus reduce the electromagnetic properties of the finished product. Therefore, how to stably prepare grain-oriented silicon steel with low titanium content is the key research direction.

[0033] In a first aspect, an embodiment of the present application provides a method for preparing grain-oriented silicon steel, including: step 100 to step 300.

[0034] Step 100, smelt hot metal with a titanium mass content ≤ 0.25% in a converter to obtain converter molten steel and transfer the converter molten steel to a ladle. Among them, the oxygen content of the converter molten steel at the end of the converter smelting is 0.06% to 0.09%; during the process of transferring the converter molten steel to the ladle, aluminum blocks and ferrosilicon of 43.2 - 48 kg / ton of molten steel and 0 - 4 kg / ton of molten steel ferrophosphorus alloy are added.

[0035] In this step, selecting hot metal with a titanium mass content ≤ 0.25% for converter smelting and the oxygen content of the converter molten steel at the end of the converter blowing are beneficial to subsequent control of the titanium content and reduction of the titanium element content brought in from the raw materials.

[0036] In this step, the addition amounts of subsequent various alloys are calculated based on the oxygen content of the converter molten steel at the end of the converter smelting. Different oxygen contents result in different addition amounts of subsequent various alloys.

[0037] When the converter tapping is completed, the ladle containing the converter molten steel enters the argon station. In the argon station, part of the alloy is added, and argon gas is blown to cool down the temperature, measure the temperature, and take samples before leaving the argon station. Thus, after adding various alloys to the converter molten steel, the oxygen content of the converter molten steel in the ladle is 0.0008% - 0.0035%, and optionally 0.0009% - 0.002%; the oxygen content of the converter molten steel in the ladle at this position can be understood as: the oxygen content of the molten steel in the ladle before RH vacuum smelting after adding each alloy in the converter ladle.

[0038] In this step, the molten steel from the converter is transferred to the ladle, and ferrosilicon at 43.2 - 48 kg per ton of molten steel, ferrophosphorus alloy at 0 - 4 kg per ton of molten steel, and aluminum blocks are added, thereby controlling the tapping process of the converter. Especially after deoxidation with aluminum, the [O] content in the molten steel is controlled, and the introduction rate of [Ti] in the molten steel by adding ferrosilicon in the converter is reduced.

[0039] In this step, compared with the addition ratio of ferrosilicon in the prior art, the added mass of ferrosilicon is increased, which can reduce the oxygen content, thereby reducing the amount of [Ti] introduced by ferrosilicon into the molten steel.

[0040] In this step, compared with the addition ratio of ferrophosphorus in the prior art, the [P] content at the end of the converter is increased, and the addition amount of ferrophosphorus during the argon station and RH refining processes is reduced. Ferrophosphorus is added under high oxygen conditions, thereby reducing the amount of [Ti] introduced by low-titanium ferrophosphorus into the molten steel. The reason for the analysis is that the P content of the finished product is fixed. The P remaining after the converter end smelting. If the remaining P increases, then the amount of ferrophosphorus alloy to be added during the subsequent smelting process will decrease, and since the ferrophosphorus alloy contains titanium, the amount of titanium introduced will be reduced.

[0041] Step 200: The molten steel from the converter is subjected to RH vacuum refining to obtain refined molten steel. Among them, during the RH vacuum refining process, the addition amount of ferrosilicon is 0 - 4.8 kg per ton of molten steel, so that the addition amount of ferrosilicon is 48 kg per ton of molten steel; the addition amount of temperature-adjusting scrap steel is 0 - 2 kg per ton of molten steel.

[0042] In this step, the addition amount of temperature-adjusting scrap steel is reduced, achieving precise temperature control, reducing the addition of temperature-adjusting scrap steel, and facilitating the reduction of the problem of titanium introduced by temperature-adjusting scrap steel.

[0043] Step 300: The refined molten steel is continuously cast to obtain grain-oriented silicon steel. Among them, the grain-oriented silicon steel includes the following chemical components in mass percentage: C: 0.03% - 0.07%, Si: 3.0% - 3.50%, Mn: 0.1% - 0.3%, P: 0.01% - 0.035%, S ≤ 0.0100%, Als: 0.01% - 0.035%, Ti ≤ 0.0030%, T.O ≤ 0.002%, and the balance is Fe and inevitable impurity elements.

[0044] According to the embodiments of the present application, by controlling the raw material components, addition amounts, and titanium introduction amounts during the steelmaking process, controlling the appropriate alloy addition amount and the oxygen content at the end of the converter during the converter smelting process, and combining with the addition amount of temperature-adjusting scrap steel and the process of optimizing the ladle slag during RH vacuum refining, the titanium content in the grain-oriented silicon steel is further stably controlled at a low level, improving the magnetic properties of the grain-oriented silicon steel and reducing the iron loss.

[0045] In addition, the preparation method of the present application does not need to reduce the alloy content in the slag through large slag volume in the converter or slag pouring operation, reducing the consumption of slag materials and improving production efficiency; and can achieve the control of extremely low titanium content.

[0046] T.O represents total oxygen, which is the sum of free oxygen in steel and oxygen element in inclusions, and is an index characterizing the amount of inclusions in steel.

[0047] In some alternative embodiments, the addition amount of ferrosilicon in the converter ladle is greater than that in the RH vacuum refining, which is beneficial to further reduce the Ti input rate and improve the performance of the steel plate.

[0048] In some alternative embodiments, step 100 specifically includes blowing molten iron with a titanium content ≤ 0.25% in a converter. At the end of the converter blowing, the end-point oxygen content is 0.06% - 0.09%. Aluminum blocks are added for deoxidation during the process of tapping the converter into the ladle, so that the [O] content of the molten steel after aluminum deoxidation is 0.0008% - 0.0035%, optionally 0.0009% - 0.002%. Thus, within this range of the oxygen content of the molten steel, this oxygen-containing environment is beneficial to reducing the Ti input rate of adding ferrosilicon to the molten steel.

[0049] Figure 1 Shows the influence of the oxygen content of the molten steel in the embodiment of the present application on the Ti input rate of ferrosilicon.

[0050] Since the added ferrosilicon contains a certain amount of titanium, and when the oxygen content in the molten steel is different, the retention rate or input rate effect of the titanium content in the ferrosilicon by the molten steel is different. When the oxygen content of the molten steel is greater than or equal to 0.0008%, the Ti input rate of the ferrosilicon by the molten steel can be further reduced, and the titanium element content of the steel grade can be further reduced. The [O] content of the molten steel after aluminum deoxidation is 0.0008% - 0.0035%, optionally 0.0009% - 0.002%. Thus, within this range of the oxygen content of the molten steel, this oxygen-containing environment is beneficial to reducing the Ti input rate of adding ferrosilicon to the molten steel.

[0051] In some alternative embodiments, in the RH refining step, metallic manganese is added, and metallic manganese is used to replace high-carbon ferromanganese to reduce the amount of Ti input into the molten steel by ferromanganese. In this way, the titanium element content of the raw and auxiliary materials is reduced, and through process optimization for reasonable distribution, the amount of it input into the molten steel is reduced, avoiding the reduction of titanium elements entering the slag and re-entering the molten steel to cause a secondary increase.

[0052] In some alternative embodiments, in the tapping and argon station steps, the temperature is controlled by blowing argon for cooling. Thus, the temperature control accuracy is improved, the use of temperature-adjusting scrap steel is reduced, and thus the amount of Ti input into the molten steel by the temperature-adjusting scrap steel is reduced.

[0053] In some alternative embodiments, before step 100, the method further includes: subjecting the molten iron to desulfurization treatment.

[0054] In some alternative embodiments, the mass content of titanium in the ferrosilicon is ≤0.015%. Using ferrosilicon with a lower [Ti] content can reduce the introduction of [Ti] content into the molten steel.

[0055] In some alternative embodiments, the ferrophosphorus alloy includes, by mass percentage, 23%-25% of phosphorus element, 70%-73% of iron element, ≤0.5% of titanium element, and inevitable impurity elements.

[0056] In some alternative embodiments, the calculation method for the addition amount of the aluminum block is: addition amount of the aluminum block (kg) = (ω[O] - 0.0020%) × 1000 × 1.125 kg / ton of molten steel, where ω[O] represents the oxygen content of the converter molten steel at the end of converter blowing.

[0057] In some alternative embodiments, the temperature-adjusting scrap steel includes, by mass percentage, 96%-97% of iron element, 3%-3.5% of silicon element, ≤0.0030% of titanium element, and inevitable impurity elements.

[0058] In this embodiment, using the corner waste of grain-oriented electrical steel as the raw material of the temperature-adjusting scrap steel can reduce the pollution of the composition and be as close as possible to the composition.

[0059] Figure 2 The effect diagram showing the influence of the temperature-adjusting scrap steel of the embodiment of the present application on the increment of titanium in the molten steel is shown. Figure 2 In, adding different masses of the temperature-adjusting scrap steel has different influences on the content of titanium element in the molten steel. From Figure 2 it can be seen that in order to further reduce the titanium content in the molten steel, the addition amount of the temperature-adjusting scrap steel is 0 to 4 kg, and can be optionally 2 - 4 kg.

[0060] In some alternative embodiments, the phosphorus element content in the refined molten steel is 0.025% to 0.035%.

[0061] In some alternative embodiments, after subjecting the molten iron with a titanium mass content ≤0.25% to converter smelting to obtain converter molten steel and transferring the converter molten steel to a ladle, the method further includes: by adding an Al2O3 slag material operation, making the mass content of Al2O3 in the ladle slag reach 43%-55%. Thus, the titanium increment in the molten steel can be reduced by reducing the ladle slag amount or reducing the titanium content in the ladle slag, and the problem that titanium in the ladle slag is reduced and enters the molten steel can be solved.

[0062] In some alternative embodiments, the ladle slag includes, by mass percentage, CaO: 17%-19%, SiO 2:19%-21%, Al2O 3: 43%-55%, MgO: 6%-9%, and the rest are inevitable impurity components. Thus, by controlling the composition of the ladle slag and avoiding the reduction of titanium oxide in the ladle slag into the molten steel, the production of low-titanium grain-oriented silicon steel from high-titanium hot metal can be achieved, and the reduction of (TiO2) in the ladle slag into the molten steel during the calming process can be avoided, thereby reducing the [Ti] content in the molten steel during the calming process.

[0063] Figure 3 The influence of the ladle slag components in the embodiments of the present application on the titanium content in the molten steel is shown. The higher the TiO2 content, the higher the titanium element content in the molten steel.

[0064] In some alternative embodiments, after continuous casting of the refined molten steel, the method further includes:

[0065] Hot rolling the slab prepared by continuous casting. The hot-rolled slab is subjected to normalizing, cold rolling, decarburizing annealing, coating with magnesium oxide, high-temperature annealing, skin-pass stretching annealing, and coating with an insulating film to obtain the finished grain-oriented silicon steel.

[0066] In a second aspect, the embodiments of the present application provide a kind of grain-oriented silicon steel prepared by the method in the first aspect.

[0067] In some alternative embodiments, the iron loss P of the grain-oriented silicon steel 17 / 50 is 0.71 - 0.85 W / kg, and the magnetic induction intensity B8 is 1.88 - 1.94 T.

[0068] Embodiment

[0069] The following embodiments more specifically describe the content disclosed in the present application. These embodiments are only for illustrative purposes, because various modifications and changes within the scope of the present application are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further treatment, and the instruments used in the embodiments are all commercially available.

[0070] Example 1

[0071] This embodiment provides a method for preparing grain-oriented silicon steel, including the following steps:

[0072] The hot metal with a titanium content of 0.14% is blown in a converter. The total mass of the hot metal is 200 tons. The oxygen content at the end of the converter blowing is 0.06%. After the converter tapping is completed, it enters the argon station, and part of the alloy is added at the argon station. Aluminum blocks are added for deoxidation during the converter tapping process, and the addition amount of aluminum blocks is 0.6525 kg / ton of steel. Control the [O] content in the molten steel to 0.0025% after adding aluminum for deoxidation during the converter tapping process;

[0073] Then ferrosilicon with a low titanium content is added. The Ti content in the ferrosilicon is 0.013%, and the addition amount is 45 kg / ton of steel. During the converter tapping process, according to the P content at the end of the converter, 3 kg / ton of ferrophosphorus is added; according to the Mn content at the end of the converter, 2 kg / ton of ferromanganese is added. Control the end temperature of the converter blowing to 1620 °C, and cool it to 1610 °C by blowing argon at the argon station;

[0074] The converter molten steel is subjected to RH vacuum refining to obtain refined molten steel. Among them, ferrosilicon is added during the RH refining process. The Ti content in the ferrosilicon is 0.013%, and the addition amount is 3 kg / ton of steel. The addition amount of steelmaking scrap for temperature adjustment during the RH refining process is 2 kg / ton of steel. The composition of the steelmaking scrap for temperature adjustment includes 96.6% iron element, 3.3% silicon element, 0.0016% titanium element and inevitable impurity elements by mass percentage;

[0075] Optimize the ladle slag by adding Al2O3-containing slag materials. After RH refining, adjust the ladle slag composition to CaO 18%, SiO2 20%, Al2O3 51%, MgO 8%, and the others are inevitable impurities.

[0076] The slab prepared by continuous casting, among which, the grain-oriented silicon steel slab includes the following chemical components by mass percentage: Among them, the grain-oriented silicon steel includes the following chemical components by mass percentage: C: 0.055%, Si: 3.3%, Mn: 0.13%, P: 0.028%, S: 0.0060%, Als: 0.0295%, Ti: 0.0014%, T.O≤0.0010%, and the balance is Fe and inevitable impurity elements.

[0077] Hot-roll the slab. The hot-rolled slab is normalized, cold-rolled, decarburized annealed, coated with magnesium oxide, high-temperature annealed, skin-passed and stretched annealed, and coated with an insulating film to obtain the finished grain-oriented silicon steel.

[0078] Example 2

[0079] The difference between this example and Example 1 is that: the addition amount of ferrosilicon during converter tapping is 43.2 kg / ton of steel, ferrophosphorus alloy is added during the converter tapping process, and the addition amount of steelmaking scrap for temperature adjustment is 0.8 kg / ton of steel.

[0080] Example 3

[0081] The difference between this embodiment and Embodiment 1 lies in that: the timing of adding the aluminum block is different. The aluminum block is added at the moment before the ladle enters the RH furnace for RH vacuum smelting, and the aluminum block starts to melt into the molten steel after entering the RH furnace.

[0082] Embodiment 4

[0083] The difference between this embodiment and Embodiment 1 lies in that: 43.2 kg of ferrosilicon and ferro-phosphorus alloy at 4 kg per ton of steel are added during the process of transferring the converter molten steel to the ladle.

[0084] Embodiment 5

[0085] The difference between this embodiment and Embodiment 1 lies in that: the adding order of ferrosilicon and the aluminum block is different. Ferrosilicon is added first during the process of transferring the converter molten steel to the ladle, and then the aluminum block is added.

[0086] Comparative Example 1

[0087] The difference from Embodiment 1 lies in that: no aluminum block is added. 26 kg per ton of steel of ferrosilicon is added during the tapping process of the converter, ferro-phosphorus alloy is added in the RH furnace for RH vacuum refining, 22 kg per ton of steel of ferrosilicon alloy is added during the RH smelting process, and the addition amount of temperature-adjusting scrap steel is 8 kg per ton.

[0088] Comparative Example 2

[0089] The difference from Embodiment 1 lies in that: the timing of adding the aluminum block is different. The ferro-phosphorus alloy in this comparative example is added in the RH furnace for RH vacuum refining.

[0090] Comparative Example 3

[0091] The difference between this comparative example and Embodiment 1 lies in that: the timing of adding the ferro-phosphorus alloy and the aluminum block is different: the aluminum block is added during the converter steel smelting, and the addition amount is the same as that in Embodiment 1. The ferro-phosphorus alloy is added in the RH furnace for RH vacuum refining. And the addition amount of temperature-adjusting scrap steel is 8 kg per ton.

[0092] Test section

[0093] Measure the Ti content, iron loss P 17 / 50 and magnetic induction intensity B8 in the grain-oriented silicon steel obtained in the embodiments and comparative examples.

[0094] Detection method for Ti content in grain-oriented silicon steel: Detect according to GB / T 4336 "Spark source atomic emission spectrometric analysis method for carbon steel and medium and low alloy steel (conventional method)".

[0095] Detection methods for iron loss and magnetic induction intensity in grain-oriented silicon steel: Detect with reference to GB / T 3655-2008 "Method for measuring magnetic properties of electrical steel sheets (strip) using Epstein frame".

[0096] Table 1

[0097]

[0098] The measured performance parameters above are averaged.

[0099] Figure 4 The graph showing the change in titanium content in the molten steel of the embodiments and comparative examples of the present application is presented. Figure 4 The Ti content in Example 1 and Comparative Example 1 at different process nodes is disclosed, demonstrating that the preparation process of Example 1 can further reduce the titanium content in molten steel or grain-oriented silicon steel compared to Comparative Example 1.

[0100] The above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technology or replacement should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A preparation method of oriented silicon steel, characterized in that, Including: Molten iron with a titanium mass content ≤ 0.25% is subjected to converter smelting to obtain converter molten steel, and the converter molten steel is transferred to a ladle. Among them, the oxygen content of the converter molten steel at the end of the converter smelting is 0.06% to 0.09%; during the transfer of the converter molten steel to the ladle, aluminum blocks, 43.2 - 48 kg / ton of molten steel of ferrosilicon, and 0 - 4 kg / ton of molten steel of ferrophosphorus alloy are added; The converter molten steel is subjected to RH vacuum refining to obtain refined molten steel. Among them, during the RH vacuum refining process, the addition amount of ferrosilicon is 0 - 4.8 kg / ton of molten steel to make the addition amount of ferrosilicon 48 kg / ton of molten steel; the addition amount of temperature-adjusting scrap steel is 0 - 2 kg / ton of molten steel; The refined molten steel is continuously cast to obtain grain-oriented silicon steel. Among them, the grain-oriented silicon steel includes the following chemical components in mass percentage: C: 0.03% - 0.07%, Si: 3.0% - 3.50%, Mn: 0.1% - 0.3%, P: 0.01% - 0.035%, S ≤ 0.0100%, Als: 0.01% - 0.035%, Ti ≤ 0.0030%, T.O ≤ 0.002%, and the balance is Fe and inevitable impurity elements.

2. The method according to claim 1, wherein The mass content of titanium in the ferrosilicon ≤ 0.015%.

3. The method according to claim 1, wherein The ferrophosphorus alloy includes 23% - 25% of phosphorus element, 70% - 73% of iron element, ≤ 0.5% of titanium element, and inevitable impurity elements in mass percentage.

4. The method according to claim 1, wherein The calculation method of the addition amount of the aluminum block is: the addition amount of the aluminum block (kg) = (ω[O] - 0.0020%) × 1000 × 1.125 kg / ton of molten steel, where ω[O] represents the oxygen content of the converter molten steel at the end of the converter blowing.

5. The method according to claim 1, wherein The temperature-adjusting scrap steel includes 96% - 97% of iron element, 3% - 3.5% of silicon element, ≤ 0.0030% of titanium element, and inevitable impurity elements in mass percentage.

6. The method according to any one of claims 1 to 5, characterized in that The phosphorus element content in the refined molten steel is 0.025% to 0.035%.

7. The method according to any one of claims 1 to 5, characterized in that, After subjecting the molten iron with a titanium mass content ≤ 0.25% to converter smelting to obtain converter molten steel and transferring the converter molten steel to the ladle, the method further includes: by adding an Al2O3 slag material operation, making the mass content of Al2O3 in the ladle slag reach 43% - 55%.

8. The method according to claim 7, wherein The ladle slag includes CaO: 17% - 19%, SiO2: 19% - 21%, Al2O3: 43% - 55%, MgO: 6% - 9% in mass percentage, and the rest are inevitable impurity components.

9. An oriented electrical steel, characterized in that, Obtained by the method according to any one of claims 1 - 8.

10. The grain-oriented electrical steel according to claim 9, characterized in that, The iron loss P of the grain-oriented electrical steel 17 / 50 is 0.71 - 0.85 W / kg, and the magnetic induction intensity B8 is 1.88 - 1.94 T.

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