Low-iron-loss high-magnetic-induction non-oriented electrical steel and preparation method thereof

Abstract

The invention discloses low-iron-loss high-magnetic-induction non-oriented electrical steel and a preparation method thereof. The preparation method comprises the steps that crude molten steel is refined, refined molten steel is obtained, and the refined molten steel comprises, by mass, 0.001%-0.004% of C, 0.85%-1.2% of Si, 0.25%-0.42% of Als, 0.24%-0.36% of Mn, 0.005%-0.025% of P, 0.0005%-0.004% of S and the balance Fe and inevitable impurities; performing continuous casting, hot rolling and cold rolling on the refined molten steel to obtain cold-rolled strip steel; and the cold-rolled strip steel is subjected to annealing treatment, the low-iron-loss high-magnetic-induction non-oriented electrical steel is obtained, the heat preservation temperature of annealing treatment ranges from 910 DEG C to 940 DEG C, and the heat preservation time ranges from 40 s to 80 s. According to the preparation method, the magnetic induction intensity of the steel can be kept unchanged while the steel loss of the electrical steel is reduced, and the alloy cost is saved.

Description

Technical Field

[0001] The present application belongs to the field of metallurgical technology, and in particular relates to a low iron loss and high magnetic induction non-oriented electrical steel and a preparation method thereof. Background Art

[0002] Non-oriented electrical steel is an important component in electrical equipment such as motors, EI cores, and small transformers. In recent years, with the continuous improvement of the comprehensive performance of these electrical equipment, the non-oriented electrical steel sheets as their raw materials are required to have ultra-low iron loss and ultra-high magnetic induction while ensuring cost advantages, so as to meet the development trend of electrical equipment to adapt to environmental protection, energy saving and high efficiency.

[0003] In the prior art, the method of increasing the silicon and aluminum content in electrical steel is often used to reduce the eddy current loss and hysteresis loss of electrical steel. However, the increase in silicon and aluminum content will reduce the magnetic induction intensity of electrical steel and increase the alloy cost. The preparation method of the prior art cannot ensure that the prepared non-oriented electrical steel can have the excellent properties of low iron loss and high magnetic induction. Summary of the invention

[0004] The embodiment of the present application provides a low iron loss and high magnetic induction non-oriented electrical steel and a preparation method thereof, which can reduce the iron loss of the electrical steel and keep its magnetic induction intensity unchanged, and save alloy costs.

[0005] In a first aspect, the present application provides a method for preparing low iron loss and high magnetic induction non-oriented electrical steel, comprising:

[0006] Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 0.001% to 0.004% C, 0.85% to 1.2% Si, 0.25% to 0.42% Als, 0.24% to 0.36% Mn, 0.005% to 0.025% P, 0.0005% to 0.004% S, and the remainder is Fe and unavoidable impurities;

[0007] The refined molten steel is continuously cast, hot rolled and cold rolled to obtain cold rolled steel strip;

[0008] The cold-rolled strip is annealed to obtain low iron loss and high magnetic induction non-oriented electrical steel. The annealing temperature is 910° C. to 940° C., and the annealing time is 40s to 80s.

[0009] According to the embodiment of the first aspect of the present application, the step of annealing the cold-rolled strip to obtain low iron loss and high magnetic induction non-oriented electrical steel includes: the holding temperature of the annealing treatment is 910℃~930℃, and the holding time of the annealing treatment is 40s~60s.

[0010] According to an embodiment of the first aspect of the present application, the step of annealing the cold-rolled strip to obtain low iron loss and high magnetic induction non-oriented electrical steel includes the following steps: the cold-rolled strip contains, by mass percentage, C: 0.001% ~ 0.003%, Si: 0.9% ~ 1.0%, Als: 0.30% ~ 0.40%, Mn: 0.25% ~ 0.35%, P: 0.015% ~ 0.025%, S: 0.0015% ~ 0.003%, and the rest is Fe and unavoidable impurities.

[0011] According to the embodiment of the first aspect of the present application, in the process of annealing the cold-rolled strip to obtain low iron loss and high magnetic induction non-oriented electrical steel, the heating time of the annealing treatment is 5s to 30s.

[0012] According to an embodiment of the first aspect of the present application, the step of continuously casting, hot rolling and cold rolling the refined molten steel to obtain a cold-rolled steel strip includes continuously casting the refined molten steel to obtain a continuously cast ingot;

[0013] The continuous casting ingot is heated, rough rolled, finished rolled, laminar cooled and coiled to obtain a hot rolled steel coil;

[0014] The hot-rolled steel coils are subjected to centralized stack cooling, uncoiling, tension straightening, descaling, pickling and cold rolling to obtain cold-rolled steel strips.

[0015] According to an embodiment of the first aspect of the present application, the steps of heating, rough rolling, finish rolling, laminar cooling and coiling the continuous casting ingot to obtain the hot-rolled steel coil include heating for 140 minutes to 350 minutes;

[0016] The furnace temperature of continuous casting billet is 1075℃~1125℃;

[0017] The temperature of rough rolling is 900℃~1100℃;

[0018] The finishing temperature of finishing rolling is 850℃~890℃;

[0019] The coiling temperature is 720°C to 760°C.

[0020] According to an embodiment of the first aspect of the present application, the steps of performing centralized stack cooling, uncoiling, straightening, descaling, pickling and cold rolling on the hot-rolled steel coil to obtain the cold-rolled steel strip include:

[0021] The concentrated cooling time is 36h to 55h.

[0022] Cold rolling is cold continuous rolling;

[0023] The total reduction rate of cold rolling is 75% to 85%, and the reduction rate of the last stand of cold rolling is 8% to 12%.

[0024] According to an embodiment of the first aspect of the present application, before the step of refining the crude molten steel to obtain the refined molten steel, the step includes: desulfurizing the molten iron to obtain desulfurized molten iron;

[0025] The desulfurized molten iron is smelted in a converter to obtain crude molten steel.

[0026] In a second aspect, the present application provides a low iron loss and high magnetic induction non-oriented electrical steel, which is prepared by the above-mentioned method for preparing low iron loss and high magnetic induction non-oriented electrical steel, and contains, by mass percentage, C: 0.001% ~ 0.004%, Si: 0.85% ~ 1.2%, Als: 0.25% ~ 0.42%, Mn: 0.24% ~ 0.36%, P: 0.005% ~ 0.025%, S: 0.0005% ~ 0.004%, and the rest is Fe and unavoidable impurities.

[0027] According to the embodiment of the second aspect of the present application, the iron loss P of the low iron loss and high magnetic induction non-oriented electrical steel is 15 / 50HZ <4.2W / kg, magnetic induction B 50 >1.720T.

[0028] The method for preparing low iron loss and high magnetic induction non-oriented electrical steel in the embodiment of the present application adopts C, Si, Als, Mn, P, and S as alloy components, does not significantly increase the amount of silicon and aluminum alloys, and does not introduce other precious alloy elements, thereby reducing the alloy cost; by adopting a high annealing and holding temperature of 910°C to 940°C and a long annealing and holding time of more than 40S, the iron loss of the electrical steel is reduced, while the magnetic induction intensity is kept unchanged, thereby improving the electromagnetic properties of the electrical steel. DETAILED DESCRIPTION

[0029] In order to make the application purpose, technical solution and beneficial technical effect of this application clearer, the application is further described in detail below in conjunction with the embodiments. It should be understood that the implementation regulations described in this specification are only for explaining this application, not for limiting this application.

[0030] For simplicity, the present application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unclearly recorded range; and any lower limit can be combined with other lower limits to form an unclearly recorded range, and any upper limit can be combined with any other upper limit to form an unclearly recorded range. In addition, although not clearly recorded, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unclearly recorded range.

[0031] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "includes..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0032] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be measured by various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application). Unless otherwise specified, the test temperature of the parameters mentioned in this application is 25° C. and the test pressure is standard atmospheric pressure.

[0033] The above application content of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of embodiments, and these implementation regulations can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0034] In the prior art, the method of increasing the silicon and aluminum content in electrical steel is often used to reduce the eddy current loss and hysteresis loss of electrical steel. However, the increase in silicon and aluminum content will reduce the magnetic induction intensity of electrical steel and increase the alloy cost. The preparation method of the prior art cannot guarantee that the prepared non-oriented electrical steel can have the excellent performance of low iron loss and high magnetic induction. The inventors found that by adopting a higher annealing and holding temperature and a longer annealing and holding time, the iron loss of electrical steel can be reduced while keeping its magnetic induction intensity unchanged, thereby improving the electromagnetic properties of electrical steel.

[0035] In order to solve the problems of the prior art, the embodiments of the present application provide a low iron loss and high magnetic induction non-oriented electrical steel and a preparation method thereof.

[0036] The present application provides a method for preparing low iron loss and high magnetic induction non-oriented electrical steel, comprising:

[0037] Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 0.001% to 0.004% C, 0.85% to 1.2% Si, 0.25% to 0.42% Als, 0.24% to 0.36% Mn, 0.005% to 0.025% P, 0.0005% to 0.004% S, and the remainder is Fe and unavoidable impurities;

[0038] The refined molten steel is continuously cast, hot rolled and cold rolled to obtain cold rolled steel strip;

[0039] The cold-rolled strip is annealed to obtain low iron loss and high magnetic induction non-oriented electrical steel. The annealing temperature is 910° C. to 940° C., and the annealing time is 40s to 80s.

[0040] Preferably, the holding temperature of the annealing treatment is 910° C. to 930° C., and the holding time of the annealing treatment is 40s to 60s.

[0041] More preferably, the holding temperature of the annealing treatment is 920° C. to 930° C., and the holding time of the annealing treatment is 40s to 50s.

[0042] Illustratively, the holding temperature of the annealing treatment may be 910°C, 915°C, 918°C, 920°C, 922°C, 925°C, 928°C, 930°C, 932°C, 935°C, 938°C, or 940°C.

[0043] Exemplarily, the holding time for the annealing treatment is 40s, 41s, 42s, 43s, 44s, 45s, 46s, 47s, 48s, 49s, 50s, 55s, 60s, 65s, 70s, 75s, and 80s.

[0044] The embodiment of the present application adopts a high annealing holding temperature of 910°C to 940°C and a long annealing holding time of more than 40S, which can promote the full growth of the strip steel grains, reduce hysteresis loss, and thus reduce the iron loss of the electrical steel, while maintaining its magnetic induction intensity unchanged, thereby improving the electromagnetic properties of the electrical steel.

[0045] In some optional embodiments, the step of annealing the cold-rolled strip to obtain low iron loss and high magnetic induction non-oriented electrical steel includes: the cold-rolled strip contains, by mass percentage, C: 0.001% ~ 0.003%, Si: 0.9% ~ 1.0%, Als: 0.30% ~ 0.40%, Mn: 0.25% ~ 0.35%, P: 0.015% ~ 0.025%, S: 0.0015% ~ 0.003%, and the rest is Fe and unavoidable impurities.

[0046] In some optional embodiments, during the process of annealing the cold-rolled steel strip to obtain non-oriented electrical steel with low iron loss and high magnetic induction, the heating time of the annealing treatment is 5s to 30s.

[0047] Exemplarily, the heating time of the annealing treatment may be 5 s, 10 s, 15 s, 20 s, 25 s, or 30 s.

[0048] The embodiments of the present application can improve the unfavorable texture components of the annealing structure by adopting a rapid heating method, thereby reducing the iron loss of the electrical steel, while maintaining its magnetic induction intensity unchanged, thereby improving the electromagnetic properties of the electrical steel.

[0049] In some optional embodiments, the step of continuously casting, hot rolling and cold rolling the refined molten steel to obtain a cold-rolled steel strip includes continuously casting the refined molten steel to obtain a continuously cast ingot;

[0050] The continuous casting ingot is heated, rough rolled, finished rolled, laminar cooled and coiled to obtain a hot rolled steel coil;

[0051] The hot-rolled steel coils are subjected to centralized stack cooling, uncoiling, tension straightening, descaling, pickling and cold rolling to obtain cold-rolled steel strips.

[0052] In some optional embodiments, the step of heating, rough rolling, finish rolling, laminar cooling and coiling the continuous casting ingot to obtain the hot rolled steel coil includes heating for 140 min to 350 min;

[0053] The furnace temperature of continuous casting billet is 1075℃~1125℃;

[0054] The temperature of rough rolling is 900℃~1100℃;

[0055] The finishing temperature of finishing rolling is 850℃~890℃;

[0056] The coiling temperature is 720°C to 760°C.

[0057] Preferably, the heating time is 150 min to 350 min;

[0058] The furnace temperature of continuous casting billet is 1080℃~1120℃;

[0059] The temperature of rough rolling is 900℃~1000℃;

[0060] The finishing temperature of finishing rolling is 855℃~885℃;

[0061] The coiling temperature is 720°C to 800°C.

[0062] In some optional embodiments, the finishing rolling is performed by hot rolling the continuous casting ingot using a 7-stand continuous rolling mill.

[0063] In some optional embodiments, the steps of performing centralized stack cooling, uncoiling, straightening, descaling, pickling and cold rolling on the hot-rolled steel coil to obtain the cold-rolled steel strip include:

[0064] The time for concentrated cooling is 36h~55h;

[0065] Cold rolling is cold continuous rolling;

[0066] The total reduction rate of the cold rolling is 75% to 85%, and the reduction rate of the last stand of the cold rolling is 8% to 12%.

[0067] Preferably, the concentrated stack cooling time is 36h to 48h.

[0068] Exemplarily, the time for concentrated stack cooling is 36h, 37h, 38h, 39h, 40h, 42h, 44h, 46h, 48h, 50h, 51h, 52h, 53h, 54h, and 55h.

[0069] The embodiment of the present application adopts a centralized stack cooling method to cool the hot-rolled steel coil, which can reduce the cooling rate. Combined with the high coiling temperature, it can play a role similar to weak normalizing annealing, coarsening the second harmful precipitate precipitated during the hot rolling process and reducing the adverse effects of the precipitate in the subsequent annealing process.

[0070] Preferably, the total reduction ratio of the cold rolling is 80% to 83%, and the reduction ratio of the last stand of the cold rolling is 8% to 10%.

[0071] In some optional embodiments, before the step of refining the crude molten steel to obtain the refined molten steel, the step includes desulfurizing the molten iron to obtain desulfurized molten iron;

[0072] The desulfurized molten iron is subjected to converter smelting to obtain crude molten steel. In some optional embodiments, the desulfurization treatment is a KR desulfurization treatment.

[0073] In the embodiment of the present application, the S content can be reduced to less than 0.001% by desulfurizing the molten iron, thereby improving the cleanliness of the molten iron.

[0074] In some optional embodiments, the step of refining the crude molten steel to obtain refined molten steel includes refining the crude molten steel in an RH furnace to obtain refined molten steel.

[0075] In some optional embodiments, after the step of annealing the cold-rolled steel strip to obtain the low iron loss and high magnetic induction non-oriented electrical steel, the step includes coating and curing the low iron loss and high magnetic induction non-oriented electrical steel.

[0076] In some optional embodiments, before the step of annealing the cold-rolled steel strip to obtain the low iron loss and high magnetic induction non-oriented electrical steel, the step includes alkali washing and degreasing the cold-rolled steel strip.

[0077] The embodiment of the present application provides a low iron loss and high magnetic induction non-oriented electrical steel, which is prepared by the above-mentioned preparation method of low iron loss and high magnetic induction non-oriented electrical steel, and contains C: 0.001% ~ 0.004%, Si: 0.85% ~ 1.2%, Als: 0.25% ~ 0.42%, Mn: 0.24% ~ 0.36%, P: 0.005% ~ 0.025%, S: 0.0005% ~ 0.004%, and the rest is Fe and unavoidable impurities.

[0078] In some optional embodiments, the iron loss P of the low iron loss and high magnetic induction non-oriented electrical steel is 15 / 50HZ <4.2W / kg, magnetic induction B 50 >1.720T.

[0079] Example

[0080] The following examples describe the disclosure of the present application in more detail, and these examples are for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present application are apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the instruments used in the examples are commercially available.

[0081] Example 1

[0082] A method for preparing low iron loss and high magnetic induction non-oriented electrical steel, comprising:

[0083] After KR desulfurization, the molten iron enters the converter, is mixed with clean scrap steel, and is smelted into crude molten steel through an oxygen blowing process. The crude molten steel enters the RH refining furnace to complete decarburization and alloying to obtain refined molten steel, wherein the refined molten steel contains C: 0.0021%, Si: 0.95%, Als: 0.31%, Mn: 0.26%, P: 0.020%, S: 0.0025%, and the rest is Fe and unavoidable impurities in terms of mass percentage;

[0084] The refined molten steel is continuously casted by a continuous casting machine to obtain a continuous casting ingot, which is heated in a hot rolling heating furnace, and then subjected to rough rolling, finishing rolling, laminar cooling and coiling to obtain a hot rolled steel coil, wherein the heating time is 180 minutes, and the furnace discharge temperature of the continuous casting ingot is 1100°C. Specifically, the continuous casting ingot is hot rolled by a rough rolling + 7-stand continuous rolling method, the rough rolling temperature is 990°C, the finishing temperature of the finishing rolling is 870°C, the coiling temperature after laminar cooling is 740°C, and the hot rolling thickness is 2.5 mm;

[0085] After the hot-rolled steel coils come off the production line, they are subjected to centralized cooling for 48 hours.

[0086] After the hot-rolled steel coil is uncoiled, the iron oxide scale on the surface of the strip is removed by straightening, descaling and pickling processes, and then the pickled hot-rolled strip is cold-rolled by a 5-stand UCM rolling mill to obtain a cold-rolled strip. The cold-rolled strip is alkali-washed and degreased and then annealed in a continuous annealing furnace. The annealed cold-rolled strip is then coated and the coating is cured in a sintering furnace to finally obtain a 50W800 electrical steel product, wherein the total reduction rate of cold rolling is 80%, the reduction rate of the last stand of cold rolling is 10%, the final rolled thickness of the cold-rolled strip is 0.5 mm, the annealing temperature is 920°C, the heating time is <30s, and the holding time is 42s.

[0087] The electromagnetic properties of the 50W800 electrical steel product prepared in Example 1 were tested, specifically according to the standard GBT3655-2008 "Method for measuring the magnetic properties of electrical steel sheets (strips) using the Epstein square circle method" to measure the magnetic properties of electrical steel.

[0088] Product performance results are: P 1.5 / 50HZ The value is 4.1W / kg, magnetic induction B 50 The value is 1.725T (test density 7.8g / cm 3 ).

[0089] After the product is used by downstream motor customers, the motor power, torque and efficiency are all qualified.

[0090] Example 2

[0091] A method for preparing low iron loss and high magnetic induction non-oriented electrical steel, comprising:

[0092] After KR desulfurization, the molten iron enters the converter, is mixed with clean scrap steel, and is smelted into crude molten steel through an oxygen blowing process. The crude molten steel enters the RH refining furnace to complete decarburization and alloying to obtain refined molten steel, wherein the refined molten steel contains C: 0.0021%, Si: 0.98%, Als: 0.30%, Mn: 0.25%, P: 0.018%, S: 0.0022%, and the rest is Fe and unavoidable impurities in terms of mass percentage;

[0093] The refined molten steel is continuously casted by a continuous casting machine to obtain a continuous casting ingot, which is heated in a hot rolling heating furnace, and then subjected to rough rolling, finishing rolling, laminar cooling and coiling to obtain a hot rolled steel coil, wherein the heating time is 180 minutes, and the furnace discharge temperature of the continuous casting ingot is 1100°C. Specifically, the continuous casting ingot is hot rolled by a rough rolling + 7-stand continuous rolling method, the rough rolling temperature is 990°C, the finishing temperature of the finishing rolling is 870°C, the coiling temperature after laminar cooling is 740°C, and the hot rolling thickness is 2.5 mm;

[0094] After the hot-rolled steel coils come off the production line, they are subjected to centralized cooling for 48 hours.

[0095] After the hot-rolled steel coil is uncoiled, the iron oxide scale on the surface of the strip is removed by straightening, descaling and pickling processes, and then the pickled hot-rolled strip is cold-rolled by a 5-stand UCM rolling mill to obtain a cold-rolled strip. The cold-rolled strip is alkali-washed and degreased and then annealed in a continuous annealing furnace. The annealed cold-rolled strip is then coated and the coating is cured in a sintering furnace to finally obtain a 50W800 electrical steel product, wherein the total reduction rate of cold rolling is 80%, the reduction rate of the last stand of cold rolling is 10%, the final rolled thickness of the cold-rolled strip is 0.5 mm, the annealing temperature is 920°C, the heating time is <30s, and the holding time is 42s.

[0096] The electromagnetic properties of the 50W800 electrical steel product prepared in Example 2 were tested, specifically according to the standard GBT3655-2008 "Method for measuring the magnetic properties of electrical steel sheets (strips) using the Epstein square circle method" to measure the magnetic properties of electrical steel.

[0097] Product performance results are: P 1.5 / 50HZ The value is 4.0W / kg, magnetic induction B 50 The value is 1.722T (test density 7.8g / cm 3 ).

[0098] After the product is used by downstream motor customers, the motor power, torque and efficiency are all qualified.

[0099] Example 3

[0100] A method for preparing low iron loss and high magnetic induction non-oriented electrical steel, comprising:

[0101] After KR desulfurization, the molten iron enters the converter, is mixed with clean scrap steel, and is smelted into crude molten steel through an oxygen blowing process. The crude molten steel enters the RH refining furnace to complete decarburization and alloying to obtain refined molten steel, wherein the refined molten steel contains C: 0.0028%, Si: 0.96%, Als: 0.31%, Mn: 0.28%, P: 0.019%, S: 0.0017%, and the rest is Fe and unavoidable impurities in terms of mass percentage;

[0102] The refined molten steel is continuously casted by a continuous casting machine to obtain a continuous casting ingot, which is heated in a hot rolling heating furnace, and then subjected to rough rolling, finishing rolling, laminar cooling and coiling to obtain a hot rolled steel coil, wherein the heating time is 180 minutes, and the furnace discharge temperature of the continuous casting ingot is 1100°C. Specifically, the continuous casting ingot is hot rolled by a rough rolling + 7-stand continuous rolling method, the rough rolling temperature is 990°C, the finishing temperature of the finishing rolling is 870°C, the coiling temperature after laminar cooling is 750°C, and the hot rolling thickness is 2.5 mm;

[0103] After the hot-rolled steel coils come off the production line, they are subjected to centralized cooling for 48 hours.

[0104] After the hot-rolled steel coil is uncoiled, the iron oxide scale on the surface of the strip is removed by straightening, descaling and pickling processes, and then the pickled hot-rolled strip is cold-rolled by a 5-stand UCM rolling mill to obtain a cold-rolled strip. The cold-rolled strip is alkali-washed and degreased and then annealed in a continuous annealing furnace. The annealed cold-rolled strip is then coated and the coating is cured in a sintering furnace to finally obtain a 50W800 electrical steel product, wherein the total reduction rate of cold rolling is 80%, the reduction rate of the last stand of cold rolling is 10%, the final rolled thickness of the cold-rolled strip is 0.5 mm, the annealing temperature is 930°C, the heating time is <30s, and the holding time is 42s.

[0105] The electromagnetic properties of the 50W800 electrical steel product prepared in Example 3 were tested, specifically according to the standard GBT3655-2008 "Method for measuring the magnetic properties of electrical steel sheets (strips) using the Epstein square circle method" to measure the magnetic properties of electrical steel.

[0106] Product performance results are: P 1.5 / 50HZ The value is 4.0W / kg, magnetic induction B 50 The value is 1.723T (test density 7.8g / cm 3 ).

[0107] After the product is used by downstream motor customers, the motor power, torque and efficiency are all qualified.

[0108] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A method for preparing low iron loss and high magnetic induction non-oriented electrical steel, characterized in that: include: Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 0.001% to 0.004% C, 0.85% to 1.2% Si, 0.25% to 0.42% Als, 0.24% to 0.36% Mn, 0.005% to 0.025% P, 0.0005% to 0.004% S, and the remainder is Fe and unavoidable impurities; Continuously casting, hot rolling and cold rolling the refined molten steel to obtain cold-rolled steel strip; The cold-rolled steel strip is annealed to obtain low iron loss and high magnetic induction non-oriented electrical steel. The annealing temperature is 910° C. to 940° C., and the annealing time is 40s to 80s.

2. The preparation method according to claim 1, characterized in that: The step of annealing the cold-rolled strip to obtain low iron loss and high magnetic induction non-oriented electrical steel includes: the annealing treatment is carried out at a holding temperature of 910° C. to 930° C., and the annealing treatment is carried out for a holding time of 40s to 60s.

3. The preparation method according to claim 1, characterized in that: The step of annealing the cold-rolled steel strip to obtain the low iron loss and high magnetic induction non-oriented electrical steel comprises: the cold-rolled steel strip contains, by mass percentage, 0.001% to 0.003% C, 0.9% to 1.0% Si, 0.30% to 0.40% Als, 0.25% to 0.35% Mn, 0.015% to 0.025% P, 0.0015% to 0.003% S, and the rest is Fe and unavoidable impurities.

4. The preparation method according to claim 1, characterized in that: In the process of annealing the cold-rolled steel strip to obtain the low iron loss and high magnetic induction non-oriented electrical steel, the heating time of the annealing treatment is 5s to 30s.

5. The preparation method according to claim 1, characterized in that: The step of continuously casting, hot rolling and cold rolling the refined molten steel to obtain a cold-rolled steel strip comprises: continuously casting the refined molten steel to obtain a continuously cast ingot; The continuous casting billet is heated, rough rolled, finish rolled, laminar cooled and coiled to obtain a hot rolled steel coil; The hot-rolled steel coils are subjected to centralized stack cooling, uncoiling, tension straightening, scale breaking, pickling and cold rolling to obtain cold-rolled steel strips.

6. The preparation method according to claim 5, characterized in that: The step of heating, rough rolling, finish rolling, laminar cooling and coiling the continuous casting ingot to obtain the hot-rolled steel coil comprises the following steps: the heating time is 140 minutes to 350 minutes; The furnace temperature of the continuous casting billet is 1075°C to 1125°C; The rough rolling temperature is 900°C to 1100°C; The finishing temperature of the finish rolling is 850°C to 890°C; The coiling temperature is 720°C to 760°C.

7. The preparation method according to claim 5, characterized in that: The steps of centrally stacking and cooling, uncoiling, straightening, descaling, pickling and cold rolling the hot-rolled steel coils to obtain cold-rolled steel strips include: The concentrated cooling time is 36h to 55h; The cold rolling is continuous cold rolling; The total reduction rate of the cold rolling is 75% to 85%, and the reduction rate of the last stand of the cold rolling is 8% to 12%.

8. The preparation method according to claim 1, characterized in that: Before the step of refining the crude molten steel to obtain refined molten steel, the step includes desulfurizing the molten iron to obtain desulfurized molten iron; The desulfurized molten iron is smelted in a converter to obtain crude molten steel.

9. A low iron loss and high magnetic induction non-oriented electrical steel, characterized in that: The low iron loss and high magnetic induction non-oriented electrical steel is prepared according to the preparation method of any one of claims 1 to 8, and contains, by mass percentage, C: 0.001% to 0.004%, Si: 0.85% to 1.2%, Als: 0.25% to 0.42%, Mn: 0.24% to 0.36%, P: 0.005% to 0.025%, S: 0.0005% to 0.004%, and the rest is Fe and unavoidable impurities.

10. The low iron loss and high magnetic induction non-oriented electrical steel according to claim 9, characterized in that: The iron loss P of the low iron loss and high magnetic induction non-oriented electrical steel is 15 / 50HZ <4.2W / kg, magnetic induction B 50 >1.720T.