Non-oriented high-silicon steel thin strip containing trace phosphorus and plane flow casting preparation method of non-oriented high-silicon steel thin strip

Abstract

The invention discloses a trace phosphorus-containing non-oriented high silicon steel thin strip and a plane flow casting preparation method thereof. The high-silicon steel thin strip comprises the following chemical components: 4.5-7.0 wt% of Si, 0.01-0.085 wt% of P, less than or equal to 0.002 wt% of C, N, O and S, and the balance of Fe and inevitable impurities. A high-silicon steel thin strip with the thickness being 0.03-0.13 mm is manufactured through plane flow casting; and the high-silicon steel thin strip with the thickness of 0.02-0.10 mm is obtained through flattening rolling with the rolling reduction smaller than or equal to 30%, and finally two-section annealing treatment is conducted to obtain the high-silicon steel thin strip with the uniform microstructure. The trace phosphorus element is added into the components, so that the wettability between molten steel and a plane flow casting cooling roller is improved, the yield is increased, the rolling reduction is controlled, the surface quality of the thin strip is improved through smooth rolling, the stacking coefficient of the finished thin strip is increased, the microstructure uniformity is promoted through two-stage annealing treatment, and the magnetic performance of the high silicon steel is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of non-oriented high silicon steel, and in particular relates to a non-oriented high silicon steel thin strip containing trace phosphorus and a planar flow casting preparation method thereof. Background Art

[0002] Non-oriented silicon steel is an important soft magnetic material, widely used in the manufacture of iron cores for large, medium and small motors, wind and hydroelectric generators. It is an indispensable key basic material in new energy vehicles, power electronics, aerospace, smart grids, rail transit, wireless charging and other fields, and plays an important role in today's energy regulation, transmission and conversion.

[0003] The magnetic properties of non-oriented silicon steel gradually increase with the increase of Si content. When the Si addition reaches 6.5%, the magnetic properties are the highest. 6.5% Si high silicon steel has excellent soft magnetic properties such as high magnetic permeability, high magnetic flux density, high resistivity, extremely low high-frequency iron loss and magnetostriction close to zero. It is one of the soft magnetic materials with the most application prospects in the future and is called "super iron core". Compared with 3.0% Si silicon steel, the resistivity of 6.5% Si high silicon steel increases significantly and the AC iron loss decreases significantly. In the power and energy industry, if 6.5% Si high silicon steel is used to make motors, it will significantly save energy and electricity consumption and greatly reduce motor noise.

[0004] However, when the Si content in silicon steel is ≥4.5%, B2 and D03 ordered structures will appear, which greatly reduces its cold working performance and makes it difficult to process using conventional cold rolling processes, restricting the large-scale production and application of high silicon steel. So far, only JFE Company in Japan has achieved industrial production of 6.5% Si high silicon steel using chemical vapor deposition (CVD) technology in the world. However, this process has the disadvantages of high energy consumption, serious equipment corrosion, toxic by-products and environmental pollution, which is not conducive to large-scale promotion and application. With the in-depth understanding of the inherent properties of high silicon steel, researchers are considering using various special preparation processes to prepare high silicon steel sheets, such as traditional rolling process (Chinese patents CN107201479A, CN104120234A), thin strip casting and rolling process (Chinese patents CN104831036A, CN105063473A), alloy plasticization process (Chinese patents CN111155023A, CN103266215A, CN110387501A) and powder rolling process (Chinese patents CN108044100A, CN108097964A). However, the production process of rolling and casting and rolling is complicated and the operation is difficult. Although the addition of alloying elements such as Cu, B, Zr, and rare earth can increase the plasticity of high silicon steel, it deteriorates its magnetic properties to a certain extent.

[0005] Chinese patent CN104046758A discloses a short-process high-efficiency cold-rolled preparation method for high-silicon steel thin strips. Through rapid solidification and strip throwing, the molten steel liquid quickly passes through the temperature range for forming the ordered phase, inhibits the formation of the ordered phase, and effectively improves the plasticity of the high-silicon steel. However, due to the high melting point, high viscosity, poor fluidity, and poor wettability between the melt and the cooling roller of high silicon steel in the rapid solidification and strip throwing forming process, the forming performance of high silicon steel is significantly affected, and the surface quality of the obtained thin strip is poor. Even through cold rolling and flattening, the surface defects cannot be completely eliminated, which affects the subsequent stacking and use of the finished thin strips. Summary of the invention

[0006] The invention discloses a non-oriented high silicon steel thin strip containing trace phosphorus and a planar flow casting preparation method thereof, so as to solve any of the above and other potential problems in the prior art.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a planar flow casting preparation method of a trace phosphorus non-oriented high silicon steel strip, the chemical composition of the high silicon steel strip is: Si is 4.5-7.0wt%, P is 0.01-0.085wt%, C≤0.002wt%, N≤0.002wt%, O≤0.002wt%, S≤0.002wt%, and the rest is Fe and unavoidable impurities, and the non-oriented high silicon steel strip with a thickness of 0.02-0.10mm is prepared;

[0008] Another object of the present invention is to provide a planar flow casting method for preparing the above-mentioned high silicon steel thin strip, and the specific steps of the planar flow casting method are as follows:

[0009] S1) weighing each chemical component according to the design ratio of high silicon steel, melting the raw materials at a temperature of 1550-1650° C. and casting into a master alloy steel ingot with uniform composition;

[0010] S2) placing the master alloy steel ingot obtained in S1) in a crucible of a planar flow casting device under the protection of an inert gas or a covering agent, heating and remelting the ingot and keeping the temperature;

[0011] S3) applying pressure above the molten steel in the crucible according to the superheat of the molten steel by means of a pressure control system of a planar casting device;

[0012] S4) Planar flow casting: under pressure, the molten steel is flow-casted onto a rotating cooling copper roller through a flat nozzle below the plane flow casting device to prepare a high silicon steel strip with a thickness of 0.03 to 0.13 mm;

[0013] S5) temper rolling: temper rolling the high silicon steel strip obtained in S4);

[0014] S6) Annealing treatment: The high silicon steel strip after the temper rolling in S5) is subjected to two-stage annealing treatment to obtain a high silicon steel strip with a thickness of 0.02 to 0.10 mm.

[0015] Furthermore, the inert gas in S2) is argon or nitrogen; the covering agent is a CaO-Al2O3-SiO2 basic molten steel covering agent, and the plane flow casting remelting temperature is 1480-1600°C.

[0016] Furthermore, the superheat degree of the molten steel in said S3) is 20-140°C and the applied pressure is 30-200 kPa.

[0017] Furthermore, in the planar flow casting process of the medium-high silicon steel in S4), the distance between the nozzle and the cooling copper roller is 0.1-2.0 mm, and the linear speed of the cooling copper roller surface is 5-50 m / s.

[0018] Furthermore, the total reduction of the temper rolling in S5) is ≤30%.

[0019] Further, the two-stage annealing treatment in S6) is specifically as follows:

[0020] S6.1) In the annealing atmosphere of H2 / N2 mixed gas, first heat to a temperature of 900-950°C at 10-20°C / min and anneal for 0.5-1h;

[0021] S6.2) Then raise the temperature to 980-1050°C at a rate of 5-10°C / s, and the annealing time is 0.5-1h.

[0022] Furthermore, the magnetic properties of the non-oriented high silicon steel strip containing trace phosphorus obtained by the plane flow casting preparation method are as follows: magnetic induction intensity B8: ≥1.27T, iron loss P 10 / 400 :≤12.48W / kg、P 2 / 5000 : ≤13.96W / kg.

[0023] A high silicon steel thin strip prepared by the above-mentioned planar flow casting preparation method is used in the manufacture of large, medium and small motor cores.

[0024] The technical principle of the present invention is:

[0025] In view of the characteristics of high silicon steel such as high melting point, high viscosity, poor fluidity, and poor wettability between melt and cooling roller, the present invention uses trace P elements to reduce the viscosity of high silicon steel, increase the fluidity of molten steel, and improve the wettability between molten steel and plane flow casting cooling roller, thereby improving the surface quality and yield rate of high silicon steel thin strips; through the grain boundary segregation of trace P during the segmented annealing process, the {111} surface texture component in the annealing texture of non-oriented silicon steel is reduced, and the {100} and {110} surface texture components are increased, thereby improving the magnetic induction intensity and reducing the steel loss of silicon steel. Adding trace P elements, combined with the advantages of rapid solidification of plane flow casting to inhibit the formation of ordered phases of high silicon steel and improve the plasticity of high silicon steel, a high silicon steel thin strip with a thickness of 0.03 to 0.13 mm and good plasticity is obtained. Through the leveling rolling with a total reduction of ≤30%, the defects of the thin strip are effectively reduced, the surface quality is improved, and the stacking coefficient of the finished thin strip is increased. The leveling rolling can also increase the driving force for the growth of high silicon steel grains in the subsequent annealing process of the thin strip, effectively reduce the annealing temperature, and reduce the annealing time. Through the subsequent short-time annealing treatment at a lower temperature, a non-oriented high silicon steel thin strip with a trace phosphorus content of 0.02 to 0.10 mm in thickness and uniform microstructure and good comprehensive magnetic properties can be obtained.

[0026] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0027] After adding a trace amount of 0.01-0.085wt% P to high silicon steel, the resistivity of silicon steel is effectively increased, the viscosity of high silicon steel is reduced, the fluidity of molten steel is increased, the wettability between molten steel and plane flow casting cooling roller is improved, and the surface quality and yield rate of high silicon steel thin strip are improved;

[0028] The characteristic that the P element basically does not segregate during the rapid solidification process of plane flow casting effectively avoids the cold working brittleness caused by the segregation of the P element during the leveling rolling process. At the same time, extending the annealing time in the finished product annealing stage promotes the grain boundary segregation of P, improves the texture component of high silicon steel, and enhances its magnetic properties.

[0029] The addition of trace P elements improves the magnetic properties of high silicon steel. Combined with the advantages of plane flow casting and rapid solidification, the formation of ordered phases in high silicon steel is suppressed, the plasticity of high silicon steel is improved, and non-oriented silicon steel strips with excellent performance are obtained.

[0030] Temper rolling with a total reduction of ≤30% can not only improve the surface quality of high silicon steel, but also increase the driving force for grain growth during annealing, reduce annealing temperature, reduce annealing time, improve the magnetic properties of high silicon steel strip, and achieve energy saving and consumption reduction.

[0031] Annealing treatment in a H2 / N2 mixed atmosphere can reduce the oxidation generated by the surface of the thin strip in contact with air during the plane flow casting process, further improving the magnetic properties of the thin strip.

[0032] The preparation of ultra-thin non-oriented high-silicon steel of 0.02-0.10 mm is achieved through a short-process and ultra-near-net-shape production process, which has many advantages such as short process flow, simple manufacturing method, and significant energy saving and consumption reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic flow chart of a planar flow casting preparation method of a trace phosphorus-containing non-oriented high silicon steel thin strip according to the present invention;

[0034] Figure 2 This is a microscopic image of the microstructure of the high silicon steel strip after annealing in Example 2 of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with embodiments:

[0036] The present invention discloses a planar flow casting preparation method for a non-oriented high silicon steel strip containing trace phosphorus, which makes full use of the characteristics of trace phosphorus elements to reduce the viscosity of high silicon steel and increase the fluidity of molten steel, improve the wettability between molten steel and the planar flow casting cooling roller, increase the resistivity of high silicon steel, improve the annealing texture, improve the surface quality and yield rate of the high silicon steel strip, and optimize the magnetic properties. Combined with the advantages of rapid solidification of planar flow casting to inhibit the formation of ordered phases of high silicon steel and improve the plasticity of high silicon steel, a high silicon steel strip with a thickness of 0.03 to 0.13 mm and good plasticity is obtained. The surface quality of the strip is improved by leveling rolling with a small reduction, and the yield rate of the finished strip is improved. Leveling rolling can also increase the driving force for the growth of high silicon steel grains during the annealing treatment of the strip, effectively reduce the annealing treatment temperature, reduce the annealing treatment time, and obtain a microstructure with uniform grain size. Annealing treatment under a H2 / N2 mixed atmosphere can reduce the oxidation generated by the surface of the strip in contact with air during the planar flow casting process, so that the comprehensive magnetic properties of the high silicon steel strip are improved by 10 to 20%. Finally, a non-oriented high silicon steel strip with a microstructure uniformity and excellent comprehensive magnetic properties containing trace phosphorus is produced with a thickness of 0.02 to 0.10 mm. The invention has many advantages such as a short process flow, a simple manufacturing method, and significant energy saving and consumption reduction.

[0037] Embodiment 1:

[0038] like Figure 1 As shown, the present invention provides a method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition mass percentage of the steel is: Si: 6.53%, P: 0.051%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and inevitable impurity elements, and the process route is: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip, and the preparation method comprises the following steps:

[0039] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1650°C and cast into a master alloy steel ingot with uniform composition;

[0040] Remelting: Place the master alloy steel ingot in the crucible of the flat flow casting equipment under argon protection and heat it to 1560℃ for remelting and heat preservation. The superheat of the steel liquid is 100℃.

[0041] Pressurizing: applying a pressure of 35 kPa above the molten steel in the crucible through a pressure control system;

[0042] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 0.60 mm, and the linear speed of the cooling copper roller surface is 30 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented silicon steel strip with a thickness of 0.065 mm;

[0043] Temper rolling: The 0.065 mm thick silicon steel strip obtained by plane flow casting is tempered with a total reduction of 30% to obtain a 0.045 mm thick flat strip;

[0044] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 950℃ at 20℃ / min for annealing for 0.5h, then heated to 1050℃ at 10℃ / s for annealing for 0.5h, and then cooled to room temperature with the furnace after annealing to obtain a trace phosphorus non-oriented silicon steel thin strip with excellent magnetic properties. The magnetic properties are: magnetic induction intensity B8: 1.29T, iron loss P 10 / 400 :9.11W / kg、P 2 / 5000 :9.43W / kg.

[0045] Embodiment 2:

[0046] A method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition of the steel is as follows: Si: 5.58%, P: 0.063%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and inevitable impurity elements. The process route is as follows: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip. The preparation method comprises the following steps:

[0047] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1620°C and cast into a master alloy steel ingot with uniform composition;

[0048] Remelting: Under the protection of CaO-Al2O3-SiO2 basic steel covering agent, the master alloy ingot is placed in the crucible of the plane flow casting equipment and heated to 1520℃ for remelting and heat preservation. The superheat of the steel liquid is 55℃;

[0049] Pressurizing: applying a pressure of 120 kPa above the molten steel in the crucible through a pressure control system;

[0050] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 1.50 mm, and the linear speed of the cooling copper roller surface is 15 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented silicon steel strip with a thickness of 0.094 mm;

[0051] Temper rolling: The 0.094 mm thick silicon steel strip obtained by plane flow casting is tempered with a total reduction of 20% to obtain a 0.075 mm thick flat strip;

[0052] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 900℃ at 20℃ / min for annealing for 1h, and then heated to 980℃ at 8℃ / s for annealing for 1h. After annealing, it is cooled to room temperature with the furnace to obtain a trace phosphorus non-oriented silicon steel thin strip with excellent magnetic properties. The microstructure micrograph of the high silicon steel thin strip after annealing is shown in Figure 2. Figure 2 As shown, the magnetic properties of silicon steel strip are: magnetic induction intensity B8: 1.30T, iron loss P 10 / 400 :11.82W / kg、P 2 / 5000 : 12.63W / kg

[0053] Embodiment 3:

[0054] A method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition of the steel is as follows: Si: 6.56%, P: 0.030%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and inevitable impurity elements. The process route is as follows: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip. The preparation method comprises the following steps:

[0055] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1580°C and cast into a master alloy steel ingot with uniform composition;

[0056] Remelting: Under the protection of nitrogen, the master alloy steel ingot is placed in the crucible of the plane flow casting equipment and heated to 1500℃ for remelting and heat preservation. The superheat of the steel liquid is 40℃;

[0057] Pressurizing: applying a pressure of 175 kPa above the molten steel in the crucible through a pressure control system;

[0058] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 0.70 mm, and the linear speed of the cooling copper roller surface is 35 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented silicon steel strip with a thickness of 0.065 mm;

[0059] Temper rolling: The 0.065 mm thick silicon steel strip obtained by plane flow casting is tempered with a total reduction of 30% to obtain a 0.045 mm thick flat strip;

[0060] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 900℃ at 15℃ / min for annealing for 0.5h, and then heated to 1000℃ at 10℃ / s for annealing for 0.5h. After annealing, it is cooled to room temperature with the furnace to obtain a non-oriented silicon steel thin strip containing trace phosphorus with excellent magnetic properties. The magnetic properties are: magnetic induction intensity B8: 1.28T, iron loss P 10 / 400 :10.05W / kg、P 2 / 5000 :9.22W / kg

[0061] Embodiment 4:

[0062] A method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition of the steel is as follows: Si: 4.97%, P: 0.082%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and inevitable impurity elements. The process route is as follows: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip. The preparation method comprises the following steps:

[0063] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1650°C and cast into a master alloy steel ingot with uniform composition;

[0064] Remelting: Under the protection of CaO-Al2O3-SiO2 basic steel covering agent, the master alloy ingot is placed in the crucible of the plane flow casting equipment and heated to 1580℃ for remelting and heat preservation. The superheat of the steel liquid is 110℃.

[0065] Pressurizing: applying a pressure of 60 kPa above the molten steel in the crucible through a pressure control system;

[0066] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 0.20 mm, and the linear speed of the cooling copper roller surface is 50 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented silicon steel strip with a thickness of 0.031 mm;

[0067] Temper rolling: The 0.031 mm thick silicon steel strip obtained by plane flow casting was tempered with a total reduction of 15% to obtain a 0.026 mm thick flat strip;

[0068] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 925℃ at 10℃ / min for annealing for 0.5h, then heated to 1050℃ at 5℃ / s for annealing for 1h, and then cooled to room temperature with the furnace to obtain a trace phosphorus non-oriented silicon steel thin strip with excellent magnetic properties. The magnetic properties are: magnetic induction intensity B8: 1.31T, iron loss P 10 / 400 :10.76W / kg、P 2 / 5000 : 11.53W / kg

[0069] Embodiment 5:

[0070] A method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition of the steel is as follows: Si: 6.02%, P: 0.085%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and unavoidable impurity elements. The process route is as follows: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip. The preparation method comprises the following steps:

[0071] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1600°C and cast into a master alloy steel ingot with uniform composition;

[0072] Remelting: Under the protection of argon, the master alloy steel ingot is placed in the crucible of the flat flow casting equipment and heated to 1530℃ for remelting and heat preservation. The superheat of the steel liquid is 70℃.

[0073] Pressurizing: applying a pressure of 130 kPa above the molten steel in the crucible through a pressure control system;

[0074] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 0.50 mm, and the linear speed of the cooling copper roller surface is 40 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented silicon steel strip with a thickness of 0.048 mm;

[0075] Temper rolling: The 0.048 mm thick silicon steel strip obtained by plane flow casting is tempered with a total reduction of 25% to obtain a 0.036 mm thick flat strip;

[0076] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 950℃ at 20℃ / min for 1h, then heated to 1030℃ at 8℃ / s for 1h, and then cooled to room temperature with the furnace to obtain a trace phosphorus non-oriented silicon steel thin strip with excellent magnetic properties. The magnetic properties are: magnetic induction intensity B8: 1.30T, iron loss P 10 / 400 :9.64W / kg、P 2 / 5000 :10.15W / kg.

[0077] Embodiment 6:

[0078] A method for preparing a thin strip of non-oriented high silicon steel containing trace phosphorus by plane flow casting, wherein the chemical composition of the steel is as follows: Si: 6.98%, P: 0.019%, C, N, O, S are all ≤ 0.002%, and the rest are Fe and inevitable impurity elements. The process route is as follows: raw material - smelting - remelting - pressurization - plane flow casting - level rolling - annealing treatment - finished thin strip. The preparation method comprises the following steps:

[0079] Melting: According to the chemical composition of the above-mentioned trace phosphorus-containing non-oriented high silicon steel, the raw materials are melted at 1600°C and cast into a master alloy steel ingot with uniform composition;

[0080] Remelting: Place the master alloy steel ingot in the crucible of the flat flow casting equipment under the protection of nitrogen, heat it to 1510℃ for remelting and keep it warm, and the superheat of the steel liquid is 50℃;

[0081] Pressurizing: applying a pressure of 100 kPa above the molten steel in the crucible through a pressure control system;

[0082] Plane casting: Under pressure, the distance between the plane nozzle below the plane casting crucible and the cooling copper roller is controlled to be 2.00 mm, and the linear speed of the cooling copper roller surface is 12 m / s, so that the molten steel is cast onto the rotating cooling copper roller to prepare a non-oriented high silicon steel strip with a thickness of 0.126 mm;

[0083] Temper rolling: The 0.126 mm thick silicon steel strip obtained by plane flow casting was tempered with a total reduction of 26% to obtain a 0.090 mm thick flat strip;

[0084] Annealing treatment: In a H2 / N2 mixed atmosphere, the flat rolled thin strip is first heated to 930℃ at 15℃ / min and annealed for 0.75h; then heated to 1000℃ at 7℃ / s and annealed for 0.75h. After annealing, it is cooled to room temperature with the furnace to obtain a trace phosphorus non-oriented silicon steel thin strip with excellent magnetic properties. The magnetic properties are: magnetic induction intensity B8: 1.27T, iron loss P 10 / 400 :12.48W / kg、P 2 / 5000 :13.96W / kg.

[0085] The above is a detailed introduction to a non-oriented high silicon steel strip containing trace phosphorus and a planar flow casting preparation method thereof provided in the embodiments of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application; at the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0086] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0087] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0088] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0089] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be protected by the specification attached to the present application.

Claims

1. A non-oriented high silicon steel strip containing trace phosphorus, characterized in that: The mass percentages of the components of the high silicon steel strip are as follows: Si is 4.5-7.0wt%, P is 0.01-0.085wt%, C≤0.002wt%, N≤0.002wt%, O≤0.002wt%, S≤0.002wt%, and the rest are Fe and unavoidable impurities.

2. A planar flow casting method for preparing a high silicon steel strip as claimed in claim 1, characterized in that: The specific steps of the planar flow casting preparation method are as follows: S1) weighing each chemical component according to the design ratio of high silicon steel, melting the raw materials at a temperature of 1550-1650° C. and casting into a master alloy steel ingot with uniform composition; S2) placing the master alloy steel ingot obtained in S1) in a crucible of a planar flow casting device under the protection of an inert gas or a covering agent, heating and remelting the ingot and keeping the temperature; S3) applying pressure above the molten steel in the crucible according to the superheat of the molten steel by means of a pressure control system of a planar casting device; S4) Planar flow casting: under pressure, the molten steel is flow-casted onto a rotating cooling copper roller through a flat nozzle below the plane flow casting device to prepare a high silicon steel strip with a thickness of 0.03 to 0.13 mm; S5) temper rolling: temper rolling the high silicon steel strip obtained in S4); S6) Annealing treatment: The high silicon steel strip after the temper rolling in S5) is subjected to two-stage annealing treatment to obtain a high silicon steel strip with a thickness of 0.02 to 0.10 mm.

3. The planar flow casting preparation method according to claim 2, characterized in that: The inert gas in S2) is argon or nitrogen; the covering agent is a CaO-Al2O3-SiO2 basic molten steel covering agent, and the plane flow casting remelting temperature is 1480-1600°C.

4. The planar flow casting preparation method according to claim 2, characterized in that: The superheat degree of the molten steel in said S3) is 20-140°C and the applied pressure is 30-200 kPa.

5. The planar flow casting preparation method according to claim 2, characterized in that: In the above S4) medium-high silicon steel plane flow casting process, the distance between the nozzle and the cooling copper roller is 0.1-2.0 mm, and the linear speed of the cooling copper roller surface is 5-50 m / s.

6. The planar flow casting preparation method according to claim 2, characterized in that: The total reduction of the temper rolling in S5) is ≤30%.

7. The planar flow casting preparation method according to claim 2, characterized in that: The two-stage annealing treatment in S6) is specifically as follows: S6.1) In the annealing atmosphere of H2 / N2 mixed gas, first heat to a temperature of 900-950°C at 10-20°C / min and anneal for 0.5-1h; S6.2) Then raise the temperature to 980-1050°C at a rate of 5-10°C / s, and the annealing time is 0.5-1h.

8. The planar flow casting preparation method according to claim 2, characterized in that: The magnetic properties of the non-oriented high silicon steel strip containing trace phosphorus obtained by the plane flow casting preparation method are as follows: magnetic induction intensity B8: ≥1.27T, iron loss P 10 / 400 :≤12.48W / kg、P 2 / 5000 : ≤13.96W / kg.

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