CN117737374A - Preparation method and product of Fe-6.5Si high silicon steel strip - Google Patents

Abstract

The invention belongs to the technical field of electrical steel preparation, and specifically relates to a preparation method and product of Fe-6.5Si high silicon steel thin strip. The invention combines a combined plane flow casting and flat rolling process, in which the plane flow casting process has a faster cooling rate, and the flow casting process suppresses the precipitation of ordered phases such as B2 and D03, thereby obtaining a cast state with good plasticity and high Silicon steel strip. The flat flow cast strip forms a {001} texture, which has a high magnetic induction. The shape and flatness of the thin strip are further optimized by flat rolling. In addition, flat rolling will also introduce higher dislocations in high silicon steel. Density, thereby promoting the recrystallization and grain growth of high silicon steel during subsequent heat treatment, thereby obtaining excellent comprehensive magnetic properties, which is conducive to the miniaturization of equipment and devices and the realization of noise reduction, and has broad application prospects.

Description

A preparation method and product of Fe-6.5Si high silicon steel thin strip

Technical field

The invention belongs to the technical field of electrical steel preparation, and specifically relates to a preparation method and product of Fe-6.5Si high silicon steel thin strip.

Background technique

High silicon steel (Fe-6.5Si) with a silicon content close to 6.5wt% has the characteristics of high resistivity and magnetic permeability, low coercive force, and near-zero magnetostriction coefficient, and is suitable for sub-kHz range. In the fields of motors, transformers and inductors. However, high silicon content exceeding 5 wt.% in silicon steel can lead to the formation of brittle ordered phases, which makes it difficult to produce high-performance Fe-6.5Si thin sheets using traditional manufacturing processes such as rolling [He Zhongzhi, Zhao Yu, Luo Haiwen .Electrical Steel[M]. Metallurgical Industry Press, 2012].

Over the past four decades, extensive research has been conducted to develop new processing methods, including deposition/diffusion annealing, thermomechanical processing, and rapid solidification techniques, to produce high-performance Fe by suppressing the order-disorder transition. -6.5Si. So far, the chemical vapor deposition (CVD) method (one of the deposition/diffusion annealing methods) is the only method that can provide 0.05-0.5mm thick Fe-6.5Si alloy commercial sheets [Y.Takada, M.Abe, S.Masuda , J.Inagaki.Commercial scaleproduction of Fe-6.5wt.%Si sheet and its magnetic properties.J.Appl.Phys.64(10),1988,5367-5369]. However, this method has shortcomings such as complex process route, great environmental damage, low productivity, and high cost, which limit the application of this method. Thermomechanical processing is usually used to produce ultra-thin silicon steel sheets with a thickness of 0.03-0.05mm, including hot rolling, cold rolling, cold rolling and heat treatment [CN102453838A, JP2005-2272913, CN202310383516.8], but it is time-consuming, complex processing routes, The high cost also limits its large-scale application.

The rapid solidification strip spinning method [CN106282501A] is a method for manufacturing continuous high silicon steel thin strips. This process is based on the strip spinning process of amorphous nanocrystalline materials. During the strip spinning process, the air flow produces uneven streamlines on the surface of the thin strip, which seriously affects The plate shape and flatness of high-silicon steel thin strips, and the cold rolling process can improve the surface quality and magnetic properties of high-silicon steel strips [CN104046758B]. However, the thickness of high-silicon steel thin strips prepared by strip spinning equipment is generally 0.02 to 0.05mm. There is limited space to improve the shape and flatness of the strips through cold rolling and other means. Moreover, the ultra-thin silicon steel makes the lamination coefficient of the core low. Affects the effectiveness of the iron core.

Contents of the invention

The present invention proposes a preparation method and product of Fe-6.5Si high-silicon steel strip to solve the problem in the prior art of the lack of a simple method for producing high-performance Fe-6.5Si.

In order to achieve the above objects, the present invention proposes the following technical solutions:

A method for preparing Fe-6.5Si high silicon steel thin strip, including the following steps:

Step 1: Melt and refine industrial pure iron and metallic silicon, and cast them to obtain an ingot;

Step 2: Cut off the skin of the ingot to obtain a small piece of ingot; heat the small piece of ingot until it melts, and cast the melted small piece of ingot onto a water-cooled rotating copper roller for rapid solidification to obtain a strip material;

Step 3: Repeat small strain rolling on the strip material at room temperature to obtain a flat rolled material;

Step 4: Perform high-temperature annealing treatment on the flat-rolled material and then cool it to finally obtain the Fe-6.5Si high-silicon steel thin strip.

Preferably, in step 1, the mass percentage of the chemical composition of the ingot is:

Si=6.5%, C≤0.20%, S≤0.0020%, Mn≤0.45%, Al≤0.55%, Ti≤0.0030%, P≤0.30%, the balance is iron and inevitable inclusions.

Preferably, the refining temperature in step 1 is 1450-1600°C.

Preferably, in step 2, the strip-shaped material has a thickness of 0.05-0.30 mm and a width of 15-30 mm.

Preferably, in step 3, the reduction amount in a single pass is not less than 10%, and the number of smoothing passes is 2 to 5.

Preferably, in step 3, the thickness of the material after smooth rolling is 0.03 to 0.15 mm.

Preferably, in step 4, the sheet-rolled material is subjected to high-temperature annealing and then cooled in an atmosphere of 10% hydrogen and 90% nitrogen.

Preferably, in step 4, the annealing temperature is 700-1200°C and the holding time is 0.5-4h.

An Fe-6.5Si high-silicon steel thin strip product is produced by a preparation method of Fe-6.5Si high-silicon steel thin strip.

Preferably, the magnetic induction intensity of the Fe-6.5Si high silicon steel strip product is B ₈ =1.20~1.35T, B ₅₀ =1.58~1.69T, and the iron loss value P _10/400 =10~20W/kg, P _{0.2/ 5000} = 8~16W/kg.

The benefits of the present invention are:

The present invention proposes a method for preparing Fe-6.5Si high silicon steel thin strip, which combines a combined plane flow casting and flat rolling process. The plane flow casting process has a faster cooling rate, and the flow casting process suppresses B2 and D03 and other harmful effects. The precipitation of sequential phases results in a cast high-silicon steel thin strip with better plasticity. The flat flow cast strip forms a {001} texture, which has a high magnetic induction. The shape and flatness of the thin strip are further optimized by flat rolling. In addition, flat rolling will also introduce higher dislocations in high silicon steel. Density, thereby promoting the recrystallization and grain growth of high silicon steel during subsequent heat treatment, thereby obtaining excellent comprehensive magnetic properties, which is conducive to the miniaturization of equipment and devices and the realization of noise reduction, and has broad application prospects.

Description of drawings

The description and drawings that constitute a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 is a schematic flow chart of a preparation method of Fe-6.5Si high silicon steel thin strip.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

The following detailed description is an exemplary description and is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meanings as commonly understood by those of ordinary skill in the art to which this invention belongs. The terminology used in the present invention is for the purpose of describing specific embodiments only and is not intended to limit the exemplary embodiments according to the present invention.

Example 1:

Please refer to Figure 1. The present invention provides a method for preparing Fe-6.5Si high silicon steel thin strip. First, industrial pure iron and metallic silicon are used as raw materials, smelted in a vacuum induction furnace and cast into an ingot. The ingot is cast. After peeling, the high-silicon steel ultra-thin strip is flat-flow cast; then the flat-flow cast high-silicon steel strip is flat-rolled at room temperature, and finally the flat-rolled high-silicon steel strip is annealed at high temperature. Specifically, it includes the following steps:

Step 1, smelting; mix pure silicon and industrial pure iron according to the composition ratio. The mixture is melted in a vacuum induction furnace, refined at 1450-1600°C, and cast into an ingot. The mass percentage of the chemical composition of the alloy is: Si=6.5 %, C≤0.20%, S≤0.0020%, Mn≤0.45%, Al≤0.55%, Ti≤0.0030%, P≤0.30%, the balance is iron and inevitable inclusions;

Step 2, plane flow casting; peel off the molten steel ingot and cut off small pieces with a total weight of 1 kilogram, then put the small pieces of high silicon steel into a quartz crucible and heat them through high-frequency induction until melted. The molten high-silicon steel alloy is then flow-cast onto a water-cooled rotating copper roller (the roller diameter is greater than 300mm), and the pressure exceeds the chamber pressure by 100T to form a rapidly solidifying continuous high-silicon steel casting strip. By adjusting experimental conditions such as copper roller speed, discharging pressure, and melting temperature, strip-shaped materials are prepared;

Step 3, face-rolling; perform multiple passes of small-strain rolling on the flat flow-cast thin strip at room temperature to obtain the face-rolled material;

Step 4, high-temperature annealing; in a 10% hydrogen + 90% nitrogen atmosphere, the flat-rolled high-silicon steel strip is subjected to a high-temperature annealing treatment at 1100°C and then cooled to finally obtain a high magnetic induction, low iron loss, non-oriented electrical steel finished strip .

In a specific embodiment, in step 1, the mixture is melted using a vacuum induction furnace and then refined at 1550°C.

In a specific implementation, in step 2, the diameter of the quartz crucible is 100 mm.

In a specific embodiment, in step 2, the roller diameter of the water-cooled rotating copper roller is greater than 300 mm, and the pressure of the water-cooled rotating copper roller exceeds the chamber pressure by 100T.

In a specific implementation, in step 2, the strip material has a thickness of 0.05-0.30 mm and a width of 15-30 mm.

In a specific implementation, in step 3, the final thickness of the material after smooth rolling in step 3 is 0.03 to 0.15 mm.

In a specific implementation, in step 3, the reduction amount in a single pass is not less than 10%, and the number of smoothing passes is 2 to 5 passes.

In a specific implementation, in step 4, the annealing temperature is 700-1200°C, and the holding time is 0.5-4 hours.

In a specific embodiment, in step 4 of step 4, the magnetic induction intensity of the finished high magnetic induction low iron loss non-oriented electrical steel thin strip is B ₈ =1.20~1.35T, B ₅₀ =1.58~1.69T, and the iron loss is Value P _10/400 = 10~20W/kg, P _0.2/5000 = 8~16W/kg.

In a specific embodiment, the thickness of the strip material in step 2 is 0.05mm and the width is 15mm; the thickness of the strip material after smooth rolling in step 3 is 0.03mm; the magnetic properties of the thin strip: B8=1.30 T, B50＝1.67T, P1T/400Hz＝10.86W/Kg, P0.2T/5kHz＝10.86W/Kg.

In a specific embodiment, in step 2, the thickness of the strip material is 0.07mm and the width is 28mm; in step 3, the final thickness of the material after smooth rolling is 0.05mm; in step 4, the magnetic properties of the thin strip The energy can be: B ₈ =1.30T, B ₅₀ =1.67T, P _1T/400Hz = 12.47W/Kg, P _0.2T/5kHz = 11.52W/Kg.

In a specific embodiment, in step 2, the thickness of the strip material is 0.30mm and the width is 28mm; in step 3, the final thickness of the material after smooth rolling is 0.15mm; the magnetic properties of the thin strip are: B ₈ =1.21T, B ₅₀ =1.59T, P _1T/400Hz =19.90W/Kg, P _0.2T/5kHz =14.44W/Kg.

The invention provides a Fe-6.5Si high-silicon steel thin strip product, which is made by the above-mentioned preparation method of Fe-6.5Si high-silicon steel thin strip.

In a specific implementation, the magnetic properties of the product are: B8=1.30T, B50=1.67T, P1T/400Hz=10.86W/Kg, P0.2T/5kHz=10.86W/Kg.

In a specific implementation, the magnetic properties of the product are: B ₈ =1.30T, B ₅₀ =1.67T, P _1T/400Hz =12.47W/Kg, P _0.2T/5kHz =11.52W/Kg.

In a specific implementation, the magnetic properties of the product are: B ₈ =1.21T, B ₅₀ =1.59T, P _1T/400Hz =19.90W/Kg, P _0.2T/5kHz =14.44W/Kg.

The present invention can efficiently prepare 6.5wt.% Si high silicon steel thin strips with different thicknesses and excellent surface quality by combining plane flow casting and flat rolling processes. The planar flow casting process has a faster cooling rate. The flow casting process suppresses the precipitation of ordered phases such as B2 and D03, thereby obtaining an as-cast high-silicon steel thin strip with good plasticity. The flat flow cast strip forms a {001} texture, which has a high magnetic induction. The shape and flatness of the thin strip are further optimized by flat rolling. In addition, flat rolling will also introduce higher dislocations in high silicon steel. Density, thereby promoting recrystallization and grain growth of high silicon steel during subsequent heat treatment, thereby obtaining excellent comprehensive magnetic properties.

The present invention adopts a flat flow casting process to prepare a high silicon steel thin strip with a thickness of 0.05-0.30mm, and then obtains a better plate shape and flatness based on the cold rolling smoothing process, and a high-silicon steel strip with a thickness of 0.03-0.15mm, and finally passes a suitable The heat treatment process is expected to produce high-silicon steel thin strip products with excellent comprehensive magnetic properties. In this study, 6.5wt.%Si high-silicon steel strips of different thicknesses were successfully prepared through planar flow casting equipment. The strips showed excellent magnetic properties after flat rolling and heat treatment because their magnetostrictive coefficient was almost zero. , and the saturation magnetic induction intensity is high, which is conducive to the miniaturization of equipment and noise reduction, and has broad application prospects.

It is known from common technical knowledge that the present invention can be implemented by other embodiments without departing from its spirit or essential characteristics. Therefore, the above-disclosed embodiments are in all respects illustrative and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a use A device for realizing the functions specified in one process or multiple processes of the flowchart and/or one block or multiple blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory that causes a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction means, the instructions The device implements the functions specified in a process or processes of the flowchart and/or a block or blocks of the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device, causing a series of operating steps to be performed on the computer or other programmable device to produce computer-implemented processing, thereby executing on the computer or other programmable device. Instructions provide steps for implementing the functions specified in a process or processes of a flowchart diagram and/or a block or blocks of a block diagram.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified. Modifications or equivalent substitutions may be made to the specific embodiments, and any modifications or equivalent substitutions that do not depart from the spirit and scope of the invention shall be covered by the scope of the claims of the invention.

Claims (10)

1. A method for preparing Fe-6.5Si high silicon steel thin strip, which is characterized in that it includes the following steps: Step 1: Melt and refine industrial pure iron and metallic silicon, and cast them to obtain an ingot; Step 2: Cut off the skin of the ingot to obtain a small piece of ingot; heat the small piece of ingot until it melts, and cast the melted small piece of ingot onto a water-cooled rotating copper roller for rapid solidification to obtain a strip material; Step 3: Repeat small strain rolling on the strip material at room temperature to obtain a flat rolled material; Step 4: Perform high-temperature annealing treatment on the flat-rolled material and then cool it to finally obtain the Fe-6.5Si high-silicon steel thin strip. 2. The preparation method of a Fe-6.5Si high silicon steel thin strip as claimed in claim 1, characterized in that in step 1, the mass percentage of the chemical composition of the ingot is: Si=6.5%, C≤0.20%, S≤0.0020%, Mn≤0.45%, Al≤0.55%, Ti≤0.0030%, P≤0.30%, the balance is iron and inevitable inclusions. 3. The method for preparing Fe-6.5Si high silicon steel thin strip according to claim 1, characterized in that the refining temperature in step 1 is 1450-1600°C. 4. The method for preparing Fe-6.5Si high silicon steel thin strip according to claim 1, characterized in that in step 2, the thickness of the strip-shaped material is 0.05~0.30mm and the width is 15~30mm. 5. A method for preparing Fe-6.5Si high silicon steel thin strip according to claim 1, characterized in that in step 3, the reduction amount in a single pass is not less than 10%, and the number of smoothing passes is 2 to 5 passes. 6. The method for preparing Fe-6.5Si high silicon steel thin strip according to claim 1, characterized in that in step 3, the thickness of the material after smooth rolling is 0.03 to 0.15 mm. 7. The preparation method of a Fe-6.5Si high silicon steel thin strip as claimed in claim 1, characterized in that, in step 4, in an atmosphere of 10% hydrogen and 90% nitrogen, the material after smooth rolling is subjected to high temperature Cool after annealing. 8. The method for preparing Fe-6.5Si high silicon steel thin strip according to claim 1, characterized in that in step 4, the annealing temperature is 700-1200°C and the holding time is 0.5-4h. 9. A Fe-6.5Si high silicon steel thin strip product, characterized in that the Fe-6.5Si high silicon steel thin strip product is the Fe-6.5Si high silicon steel thin strip as described in any one of claims 1 to 8 preparation method. 10. A Fe-6.5Si high silicon steel thin strip product according to claim 9, characterized in that the magnetic induction intensity of the Fe-6.5Si high silicon steel thin strip product is B ₈ =1.20~1.35T, B ₅₀ = 1.58~1.69T, iron loss value P _10/400 = 10~20W/kg, P _0.2/5000 = 8~16W/kg.