Iron-based amorphous alloy strip and preparation method thereof, amorphous alloy iron core and transformer

Abstract

The invention relates to the technical field of soft magnetic materials, in particular to an iron-based amorphous alloy strip, a preparation method of the iron-based amorphous alloy strip, an amorphous alloy iron core and a transformer. The iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities. Nicks distributed at intervals are formed in the surface of the iron-based amorphous alloy strip; the iron-based amorphous alloy strip has B80 / BS > = 0.96, where B80 / BS is the ratio of the magnetic flux density B80 generated when an external magnetic field of 80 A / m is applied to the iron-based amorphous alloy strip to the saturation magnetic flux density BS of the iron-based amorphous alloy strip. According to the amorphous iron-based alloy strip disclosed by the invention, the effective component proportion is combined with the strip for nicking, B80 can be effectively improved, the magnetic density design space of a transformer iron core is improved, the soft magnetic performance is improved, and meanwhile, a transformer has relatively low noise and no-load loss.

Description

Technical Field

[0001] The invention relates to the technical field of soft magnetic materials, and in particular to an iron-based amorphous alloy strip and a preparation method thereof, an amorphous alloy iron core and a transformer. Background Art

[0002] At present, in the preparation process of amorphous transformers at home and abroad, iron-based amorphous strips with a saturation magnetic induction intensity of about 1.56T are generally used. Compared with the saturation magnetic induction intensity of silicon steel close to 2.0T, iron-based amorphous has the disadvantage of increasing volume when preparing transformers. In order to enhance the competitiveness of iron-based amorphous materials in the transformer industry, iron-based amorphous materials with a saturation magnetic induction intensity greater than 1.6T have been developed at this stage.

[0003] Theoretically, the higher the saturation flux density of the material used to make the transformer, the larger the design space of the transformer design flux density. However, in fact, according to the BH curve, when the amorphous alloy strip is greater than 80A / m, the increase in magnetic flux density tends to be gentle, and even if the magnetic field strength is increased, the change in magnetic flux density is not large. Therefore, in practical applications, the theoretical effective magnetic flux density can be regarded as the rated current B. 80 It is the reference rather than the saturation magnetic flux density, B 80 The higher the value, the larger the magnetic density design space of the amorphous alloy transformer. Therefore, B 80 The improvement has a huge impact on the design of transformers. 80 It can also be regarded as effective magnetic induction intensity. To develop high B 80 amorphous strip to improve the soft magnetic properties of amorphous strip to meet the use requirements of amorphous core and amorphous transformer. Summary of the invention

[0004] The invention provides an iron-based amorphous alloy strip and a preparation method thereof, an amorphous alloy iron core and a transformer, which are used to solve the problem that the existing amorphous strip has poor soft magnetic properties.

[0005] According to a first aspect of the present invention, the present invention provides an iron-based amorphous alloy strip, wherein the iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities; the surface of the iron-based amorphous alloy strip has scratches arranged at intervals; The iron-based amorphous alloy strip B 80 / B S ≥0.96, among which B 80 / B S is the magnetic flux density B generated when an external magnetic field of 80A / m is applied to the Fe-based amorphous alloy strip 80 Relative to the saturation magnetic flux density B of the iron-based amorphous alloy strip S ratio.

[0006] Furthermore, the B of the iron-based amorphous alloy strip is 80 / B S ≥0.97; Preferably, the B 80 / B S ≥0.98.

[0007] Further, in the iron-based amorphous alloy strip, the atomic percentage of Fe is 80.0-84.0, the atomic percentage of Si is 2.0-8.0, the atomic percentage of B is 10.0-14.0, and the atomic percentage of C is 0.5-1.2; Preferably, in the iron-based amorphous alloy strip, the atomic percentage of Fe is 81.0-82.0, the atomic percentage of Si is 4.0-7.0, the atomic percentage of B is 11.0-13.0, and the atomic percentage of C is 0.8-1.1.

[0008] Furthermore, the notches are continuous linear notches, and the interval between two adjacent notches is 2 mm to 40 mm; the depth of the notches is 2 μm to 10 μm; the width of the notches is 15 μm to 45 μm; and the notches are 70 to 90° with respect to the casting direction of the iron-based amorphous alloy strip.

[0009] Furthermore, the thickness of the iron-based amorphous alloy strip is 23-32 μm, and the width is 100-300 mm; the saturation magnetic induction intensity of the iron-based amorphous alloy strip is ≥1.60T.

[0010] Furthermore, the loss of the iron-based amorphous alloy strip is ≤0.0646 W / kg and the excitation power is ≤0.096 VA / kg under the conditions of magnetic density 1.3 T and 50 Hz; the loss is ≤0.0825 W / kg and the excitation power is ≤0.131 VA / kg under the conditions of magnetic density 1.4 T and 50 Hz.

[0011] According to the second aspect of the present invention, the present invention also provides a method for preparing the above-mentioned iron-based amorphous alloy strip, comprising weighing each component according to a proportion, and sequentially preparing the strip through batching, smelting, refining and single-roller rapid quenching.

[0012] Preferably, the smelting temperature is 1350-1550°C, and the time is 90-140 min; the refining temperature is 1350-1470°C, and the refining time is 60-100 min; and the single-roller quenching time is 30-60 min.

[0013] According to a third aspect of the present invention, the present invention further provides an amorphous alloy core, which is formed by winding the above-mentioned amorphous alloy strip.

[0014] According to a fourth aspect of the present invention, the present invention further provides a transformer, comprising a winding and the above-mentioned iron core.

[0015] The present invention provides an iron-based amorphous alloy strip that can effectively improve B by combining an effective composition ratio with the strip for scoring. 80 , improve the magnetic density design space of the transformer core, improve the soft magnetic properties, and in the amorphous alloy transformer core with the same performance, the iron-based amorphous alloy strip of the present invention can be used to make the core smaller, with a smaller volume and a smaller number of laminations, which can indirectly reduce the working noise of the core. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The iron core in the transformer is formed by curling an amorphous iron-based alloy strip. In view of the problem that the existing amorphous strip has poor soft magnetic properties, in a first typical embodiment of the present invention, the present invention provides an iron-based amorphous alloy strip. According to some specific embodiments of the present invention, the iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities; the surface of the iron-based amorphous alloy strip has a plurality of intervally arranged notches; B of Fe-based amorphous alloy strip 80 / B S ≥0.96, among which B 80 / B S is the magnetic flux density B generated when an external magnetic field of 80A / m is applied to the iron core made of iron-based amorphous alloy strip 80 Relative to the saturation magnetic flux density B of the iron-based amorphous alloy strip S ratio.

[0018] The present invention has found through experiments that by adjusting the contents of Fe, Si, B and C in the iron-based amorphous alloy strip, a better saturation magnetic induction intensity can be obtained, and further notches are set on the surface of the iron-based amorphous alloy strip. S remains unchanged, while B 80 It is improved. The original band B 80 / B S All are less than 0.95; B 80 / B S ≥0.96, B 80 / B SThe improvement can further optimize the design of the transformer core, reduce the size of the transformer and reduce costs.

[0019] The iron core is the key to manufacturing transformer products. The following formula (1) is the formula of the transformer principle: U=4.44·f·N·B0·Sc / 104(V) (1)

[0020] Among them, U refers to voltage, f refers to frequency, N refers to the number of turns of the iron core, and Sc refers to the effective cross-sectional area of ​​the iron core.

[0021] It can be seen from the above formula that the magnetic flux density B0 of the iron core is inversely proportional to the effective cross-sectional area Sc. Therefore, under the premise of ensuring a certain magnetic flux, the larger the effective cross-sectional area Sc, the smaller the magnetic flux density B0.

[0022] The iron-based amorphous alloy strip of the present invention is scored to produce a transformer core. 80 The effective magnetic flux density is increased, that is, under the conditions of U voltage, f frequency, and N number of turns of the core being exactly the same, the cross-sectional area of ​​the core will be reduced; the reduction in the cross-sectional area of ​​the core means that the amount of iron-based amorphous alloy strip material used is reduced, and the number of amorphous alloy strip laminations in the core cross section is reduced, thereby reducing the noise generated by vibration when the transformer is working.

[0023] Furthermore, the B of the iron-based amorphous alloy strip is 80 / B S ≥0.97; Preferably, the B 80 / B S ≥0.98.

[0024] According to some specific embodiments of the present invention, in the iron-based amorphous alloy strip, the atomic percentage of Fe is 80.0-84.0, the atomic percentage of Si is 2.0-8.0, the atomic percentage of B is 10.0-14.0, and the atomic percentage of C is 0.5-1.2.

[0025] In the above-mentioned iron-based amorphous alloy strip, the Fe element is a ferromagnetic element and is the main source of magnetism of the iron-based amorphous alloy strip. A high Fe content is an important guarantee for the strip to have a high saturation magnetic induction intensity value; but too high a Fe element will lead to a decrease in the amorphous forming ability of the alloy, making industrial production difficult to achieve. In this application, the atomic percentage of Fe is 80.0 to 84.0. Specifically, the atomic percentage of Fe can be 80.0, 80.5, 81, 82, 82.5, 83, 83.5 or 84, etc. In a specific embodiment, the atomic percentage of Fe is 81.0 to 82.0.

[0026] Si and B are amorphous forming elements, which are necessary conditions for the alloy system to form amorphous under industrial production conditions. The atomic percentage of Si element is 2.0-8.0. Too low will lead to a decrease in amorphous forming ability and affect the magnetic properties of the strip. Too high will deviate from the eutectic point and also reduce the amorphous forming ability. In a specific embodiment, the content of Si is 4.0-7.0, specifically, the content of Si is 4.0, 4.5, 5.5, 6.0, 6.5 or 7.0, etc.; the range of B element is 10.0-14.0. When it is less than 10, the amorphous forming ability of the alloy is low. When it is greater than 14, it deviates from the eutectic point and the amorphous forming ability of the alloy is reduced. In a specific embodiment, the content of B is 11.0-13.0.

[0027] The C element has the function of improving the rectangularity and B S The effect of miniaturizing the iron core and reducing noise is achieved. The atomic percentage of C element is 0.5-1.2. Too low an effect is shown, while too high an atomic percentage will cause the material to become brittle and reduce thermal stability, making it difficult to be manufactured into an iron core. In order to make the iron-based amorphous alloy strip have higher rectangularity and B S In a specific embodiment, the C content is 0.8-1.1. Specifically, the C content is 0.8, 0.85, 0.9, 0.95, 1.0, 1.05 or 1.1, etc.

[0028] In the above scheme, the soft magnetic properties of the iron-based amorphous alloy strip can be effectively improved by adjusting the contents of Fe, Si, B and C.

[0029] According to some specific embodiments of the present invention, the spacing between two adjacent notches is 2mm to 40mm (preferably 10mm-30mm, and further preferably 20mm); the depth of the notch (the height from the bottom of the notch groove to the reference plane of the strip surface) is 2μm to 10μm (further preferably 2-5μm, and further preferably 3.5μm); the width of the notch is 15μm to 45μm (preferably 20μm to 30μm, and preferably 25μm); and the notch is 70 to 90° with the casting direction of the iron-based amorphous alloy strip.

[0030] According to some specific embodiments of the present invention, the thickness of the iron-based amorphous alloy strip is 23-32 μm, and the width is 100-300 mm; the saturation magnetic induction intensity of the iron-based amorphous alloy strip is ≥1.62 T, and the coercive force is ≤4 A / m.

[0031] For amorphous strips, strip thickness is one of the important parameters affecting its core loss, which is also the main reason why amorphous strips are superior to silicon steel sheets in terms of no-load loss. The core loss of soft magnetic materials mainly includes three parts: hysteresis loss, eddy current loss, and residual loss. The thickness directly affects the size of eddy current loss. For magnetic materials, eddy currents will appear at the domain wall. The flow of eddy currents will generate magnetic flux in the opposite direction to the magnetic flux generated by the external magnetic field at every moment. The deeper into the material, the stronger this reverse effect is, resulting in serious unevenness of magnetic induction intensity and magnetic field intensity along the cross section of the sample. In terms of equivalent, the magnetic induction intensity inside the material is repelled to the surface of the material. This phenomenon is called skin effect. This is why soft magnetic materials are made into thin strips - to reduce the effect of eddy currents. However, for amorphous strips, the thinner the better. The thinner the strip, the greater the wear of the tool during the subsequent shearing process of the core, the more strip groups will be added, and the cost of the core will be increased. Considering the above two aspects, the appropriate thickness of the amorphous strip is 23-32μm.

[0032] Although the hysteresis loss of amorphous state is small, its generalized eddy current loss (iron loss-hysteresis loss) is several dozen to about 100 times larger than the classical eddy current loss determined under the assumption of uniform magnetization. The difference between the generalized eddy current loss and the classical eddy current loss is called abnormal eddy current loss or excess loss, which is mainly caused by non-uniform magnetization changes. The abnormal eddy current loss in this amorphous alloy is large, which may be due to the large width of the magnetic domain in the amorphous alloy, resulting in a fast displacement speed of the domain wall, and thus a large speed of non-uniform magnetization change. The current method of reducing abnormal eddy current loss is to use the method of scoring on the surface of the strip, including laser scoring, mechanical scoring, etc.

[0033] According to some specific embodiments of the present invention, the loss of the amorphous scored tape is ≤0.0646 W / kg and the excitation power is ≤0.096 VA / kg under the conditions of magnetic density 1.3 T and 50 Hz; the loss is ≤0.0825 W / kg and the excitation power is ≤0.131 VA / kg under the conditions of magnetic density 1.4 T and 50 Hz.

[0034] In the second typical embodiment of the present invention, the present invention also provides a method for preparing the above-mentioned iron-based amorphous alloy strip, including weighing each component according to the ratio, and obtaining it through batching, smelting, refining and single-roll quenching in sequence; wherein the specific process of batching, smelting, refining and single-roll quenching can be carried out according to the process well known to those skilled in the art, and there is no special restriction on this in this application; however, for the amorphous alloy of the above-mentioned specific composition of the present invention, there are still differences, for example: the smelting temperature is 1350-1550°C, and the time is 90-140min; the refining temperature is 1350-1470°C, and the refining time is 60-100min; the single-roll quenching time is 30-60min. The iron-based amorphous alloy strip obtained by the above-mentioned preparation method is not completely amorphous, and its critical thickness is at least 45μm, and its willfulness is good, and it is continuous when folded 180°.

[0035] In a third typical embodiment of the present invention, the present invention further provides an iron core formed by winding the above-mentioned iron-based amorphous alloy strip.

[0036] In a fourth typical embodiment of the present invention, the present invention further provides a transformer, comprising a winding and the above-mentioned iron core.

[0037] The above-mentioned iron core is assembled into a transformer. For a K200KVA transformer, the noise of this amorphous distribution transformer is 40-43db, and the no-load loss is 85-90W, which is 3-5db lower than that of a conventional amorphous distribution transformer, and the no-load loss is reduced by 5%-10%.

[0038] The technical effects of the present invention are described in detail below through specific embodiments.

[0039] Embodiments 1 to 15

[0040] The embodiments provide an amorphous iron-based alloy strip, which is composed of main elements of Fe, Si, B and C and inevitable impurities; the surface of the iron-based amorphous alloy strip has a plurality of spaced grooves, and the main elements of Fe, Si, B and C are shown in Table 1 below, and the characteristics of the grooves are: the spacing between two adjacent grooves is 2mm to 40mm, preferably 10mm-30mm, and more preferably 20mm; the depth of the groove is 2μm to 10μm, more preferably 2-5μm, and more preferably 3.5μm; the width of the groove is 20μm to 30μm, preferably 25μm; the groove is 90° to the casting direction of the iron-based amorphous alloy strip.

[0041] The magnetic induction sound intensity B of the amorphous iron-based alloy strip without notch treatment and after notch treatment was tested by vibrating sample magnetometer S , B 80 , the results are shown in Table 1 below.

[0042] The iron-based amorphous alloy strips without notching treatment (amorphous original strips) and the iron-based amorphous alloy strips after notching treatment (amorphous notched strips) were cut, formed and subjected to magnetic field heat treatment (the magnetic field intensity of the magnetic field heat treatment was 1200A / m, the temperature was 350°C, and the holding time was 120min). The core loss and excitation power of the iron-based amorphous alloy strips before and after notching treatment were tested under the conditions of 50Hz, 1.3T and 1.4T. Table 1 lists the alloy composition, B of the embodiments of the present invention (S1-S15) S , B 80 , excitation power (Pe), core loss (P).

[0043] Table 1

[0044] It can be seen from the experimental results in Table 1 that the alloy compositions of the embodiments of the present invention can obtain good saturation magnetic induction intensity, the amorphous original strip Bs is not less than 1.601T, B 80 Not less than 1.493T, the amorphous notched tape Bs is the same as the amorphous original tape, but B 80 Changes, amorphous notch band B 80 Not less than 1.554T, the saturation magnetic flux density Bs of the amorphous notched belt of the present invention is not lower than the conventional iron-based amorphous material with a saturation magnetic flux density of 1.56T currently used in power transformers. It can be basically inferred that the amorphous notched belt B8 of the present invention must be higher than the conventionally used B80 of 1.56T. 80 The improvement can further optimize the design of transformer core, reduce the size of transformer and reduce the cost. It can be seen from the performance of amorphous notched tape in Table 1 that under the conditions of magnetic density 1.3T and 50Hz, the loss of amorphous notched tape is ≤0.0646W / kg and the excitation power is ≤0.096VA / kg; under the conditions of magnetic density 1.4T and 50Hz, the loss is ≤0.0825W / kg and the excitation power is ≤0.131VA / kg; based on the excellent magnetic properties, when optimizing the transformer design, a transformer with excellent performance can be obtained.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An iron-based amorphous alloy strip, characterized in that: The iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities; the surface of the iron-based amorphous alloy strip has intervally arranged notches; The iron-based amorphous alloy strip B 80 / B S ≥0.96, among which B 80 / B S is the magnetic flux density B generated when an external magnetic field of 80A / m is applied to the Fe-based amorphous alloy strip 80 Relative to the saturation magnetic flux density B of the iron-based amorphous alloy strip S ratio.

2. The iron-based amorphous alloy strip according to claim 1, characterized in that: The iron-based amorphous alloy strip B 80 / B S ≥0.97; Preferably, the B 80 / B S ≥0.

98.

3. The iron-based amorphous alloy strip according to claim 1, characterized in that: In the iron-based amorphous alloy strip, the atomic percentage of Fe is 80.0-84.0, the atomic percentage of Si is 2.0-8.0, the atomic percentage of B is 10.0-14.0, and the atomic percentage of C is 0.5-1.2; Preferably, in the iron-based amorphous alloy strip, the atomic percentage of Fe is 81.0-82.0, the atomic percentage of Si is 4.0-7.0, the atomic percentage of B is 11.0-13.0, and the atomic percentage of C is 0.8-1.

1.

4. The iron-based amorphous alloy strip according to claim 1, characterized in that: The notches are continuous linear notches, and the interval between two adjacent notches is 2 mm to 40 mm; the depth of the notches is 2 μm to 10 μm; the width of the notches is 15 μm to 45 μm; and the notches are 70 to 90 degrees with respect to the casting direction of the iron-based amorphous alloy strip.

5. The iron-based amorphous alloy strip according to claim 1, characterized in that: The thickness of the iron-based amorphous alloy strip is 23-32 μm, and the width is 100-300 mm; the saturation magnetic induction intensity of the iron-based amorphous alloy strip is ≥1.60T.

6. The amorphous alloy strip according to any one of claims 1 to 5, characterized in that: The iron-based amorphous alloy strip has a loss of ≤0.0646 W / kg and an excitation power of ≤0.096 VA / kg under the conditions of a magnetic density of 1.3 T and 50 Hz; and has a loss of ≤0.0825 W / kg and an excitation power of ≤0.131 VA / kg under the conditions of a magnetic density of 1.4 T and 50 Hz.

7. The method for preparing the iron-based amorphous alloy strip according to any one of claims 1 to 6, characterized in that: The method comprises weighing each component according to a proportion, and obtaining the component through batching, smelting, refining and single-roller rapid quenching in sequence.

8. The preparation method according to claim 7, characterized in that: The smelting temperature is 1350-1550° C., and the time is 90-140 min; the refining temperature is 1350-1470° C., and the refining time is 60-100 min; and the single-roller rapid quenching time is 30-60 min.

9. An amorphous alloy core, characterized in that: The amorphous alloy strip according to any one of claims 1 to 6 is wound.

10. A transformer, characterized in that: It comprises a winding and the iron core as claimed in claim 9.

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