WO2021128930A1 - Iron-based amorphous ribbon and preparation method therefor - Google Patents

Abstract

The present invention provides an iron-based amorphous ribbon produced by controlling melt pool activity. During preparation of an iron-based amorphous ribbon, melt pool activity is as shown in formula (I); the present application further provides a preparation method for an iron-based amorphous ribbon. By means of restricting melt pool activity within a certain range, the present application can ensure continuous preparation of iron-based amorphous ribbons over a long period of time, facilitating the smooth running of iron-based amorphous ribbon preparation, and improving strip material quality; γ＝(100a) ^b (I).

Description

Iron-based amorphous thin ribbon and preparation method thereof

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201911368654.9, and the invention title is "an iron-based amorphous ribbon and its preparation method" on December 26, 2019, the entire content of which is incorporated by reference Incorporated in this application.

Technical field

The invention relates to the technical field of iron-based amorphous alloys, in particular to an iron-based amorphous ribbon and a preparation method thereof.

Background technique

The iron-based amorphous strip has excellent soft magnetic properties and can be used as the core material of distribution transformers, which greatly reduces the no-load loss of the transformer. On the other hand, the iron-based amorphous strip has a short production process and low production loss.

As an energy-saving functional material, the formation of iron-based amorphous strips requires rapid cooling to obtain an amorphous state, but rapid cooling greatly increases the difficulty of production. In the rapid cooling method, the single-roll method is generally used to prepare the amorphous strip. The molten steel flows through a high-speed rotating cooling roller, and the cooling roller instantly takes away the heat of the molten steel to form the required amorphous strip.

When the single-roll method is used to prepare amorphous thin strip, in order to meet the requirements of the thin strip, it is necessary to control the amount of molten steel passing through. Usually, a slit nozzle is used to inject the molten steel onto the surface of the cooling roll. Shaped molten pool (referred to as "melt pool"), whereby the molten steel ladle is supplied with molten liquid while the cooling roll is rapidly solidified by rotation to form an amorphous strip with a certain width. Because molten steel has a certain surface tension and viscosity, the purity of molten steel plays a key role in the preparation of amorphous ribbons.

The preparation process of the existing iron-based amorphous strip includes three processes: raw material smelting, tundish stabilization and rapid cooling forming; the cost of raw materials accounts for the largest part of the total cost of the strip, and the iron-based amorphous strip is mainly made of iron, silicon and boron. Or iron silicon boron carbon system, in which the impurity elements in raw materials such as industrial pure iron, silicon iron/metal silicon, and boron iron are relatively high, which seriously affects the ability of amorphous formation, and has a great impact on the performance and manufacturing stability of amorphous strips. It has a big impact. If the purity of the raw materials is simply controlled, the manufacturing cost is very high. Therefore, it is necessary to develop a method that can solve the problem of manufacturing continuity and cost.

Summary of the invention

The technical problem solved by the present invention is to provide an iron-based amorphous ribbon. The iron-based amorphous ribbon provided by the application solves the problem of anterograde in the preparation of the amorphous ribbon by controlling the melting pool activity, and improves the strip material. the quality of.

In view of this, the present application provides an iron-based amorphous ribbon for controlling the activity of the molten pool, which is characterized in that the activity of the molten pool during the preparation process of the iron-based amorphous ribbon is as shown in formula (I):

γ=(100a) ^b (Ⅰ);

Among them, γ is the melting pool activity, γ=0.5～0.95;

a is the mass percentage of Al in the molten pool, a≤0.2wt%;

b is the mass percentage of C in the molten pool, b≤15wt%.

Preferably, the γ = 0.6 to 0.95.

Preferably, the a=0.11 wt% to 0.17 wt%.

Preferably, the b=1.0~5.0wt%.

This application also provides a method for preparing an iron-based amorphous ribbon, which includes the following steps:

The molten steel with a certain proportion is sedated, and the sedated molten steel is flowed from the nozzle to the surface of the cooling roll and sprayed to obtain an iron-based amorphous ribbon;

The activity of the molten pool formed by the molten steel flowing from the nozzle to the surface of the cooling roll is shown in formula (I):

γ=(100a) ^b (Ⅰ);

Among them, γ is the melting pool activity, γ=0.5～0.95;

a is the mass percentage of Al in the molten pool, a≤0.2wt%;

b is the mass percentage of C in the molten pool, b≤15wt%.

Preferably, the continuous preparation time of the iron-based amorphous ribbon is ≥170 min.

Preferably, the content of Fe in the molten steel is 79-83 at%, the content of Si is 6-10 at%, the content of B is 10-14 at%, and the content of C is 0-1.5 at%.

Preferably, the lamination factor of the iron-based amorphous ribbon is ≥89%.

This application provides an iron-based amorphous ribbon, which limits its melting pool activity; experimental results show that this application can guarantee the iron-based amorphous ribbon by limiting the melting pool activity within a certain range. The thin strip is continuously prepared for a long time, which ensures the anterograde problem of the preparation of the iron-based amorphous thin strip and improves the quality of the strip.

Detailed ways

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

In the preparation of iron-based amorphous ribbon by the single-roll method, the thickness of the ribbon in the width direction will be different. The difference between the maximum thickness and the minimum thickness in the width direction of the ribbon is called extreme difference. Under conditions of change, the size of the extreme difference in the thin strip production process often shows inconsistencies. One reason for such differences is that the characteristics of the molten pool are inconsistent; similarly, in the amorphous alloy thin strip prepared by the single-roll method , The circumferential direction of the thin strip will form white channels with the increase of the mold roll speed and the extension of the pouring time, which will seriously affect the continuity of production. Therefore, the characteristics of the melting pool during the preparation of amorphous thin ribbon by the single-roll method will affect the performance of the ribbon. In order to ensure high-quality performance and long-term continuity of the preparation of amorphous thin ribbons, adjustments are currently made mainly through the temperature of molten steel, the level of molten steel and the purity of raw materials during the spraying process; and if the characteristics of the molten pool are directly considered to inhibit the spraying process Problems such as extremely poor strips, white runs, and reduction of strip loss are also an important research direction.

In view of this, in order to improve the antegrade degree of iron-based amorphous ribbon preparation, the present application provides an iron-based amorphous ribbon that controls the activity of the molten pool. This type of iron-based amorphous ribbon defines the melting pool during the preparation process. The activity within a certain range can ensure the anterograde of the iron-based amorphous ribbon and improve the quality of the iron-based amorphous ribbon. The embodiment of the present invention discloses an iron-based amorphous ribbon for controlling the activity of the molten pool, which is characterized in that the activity of the molten pool during the preparation process of the iron-based amorphous ribbon is as shown in formula (I):

γ=(100a) ^b (Ⅰ);

Among them, γ is the melting pool activity, γ=0.5～0.95;

a is the mass percentage of Al in the molten pool, a≤0.2wt%;

b is the mass percentage of C in the molten pool, b≤15wt%.

The present application provides an iron-based amorphous ribbon. The iron-based amorphous ribbon solves the anterograde problem of long-term preparation of amorphous ribbons by controlling the activity of the molten pool, and improves the strip material of the iron-based amorphous ribbon. quality. During the preparation of the iron-based amorphous ribbon, molten steel is sprayed from the nozzle, and a molten pool is formed between the molten steel on the surface of the cooling roll and the cooling roll. The intuitive manifestation of the molten pool activity is the stability of the molten steel; the molten pool activity is too high. It will affect the smoothness and stability of the molten steel sprayed from the nozzle of the amorphous strip, and affect the quality of the strip forming. The activity of the molten pool is related to the values of a and b mentioned in the present invention, as well as the impurities contained in the molten steel. In this application, the applicant defines the activity of the molten pool as "the activity of the molten pool", which is represented by the symbol γ. After research, the Al and C in the molten pool directly affect the activity of the molten pool, that is, γ=(100a) ^b ; the smaller the value of the molten pool activity, the longer the strip preparation time is within a certain range of the molten pool activity value. Conversely, the greater the activity value of the molten pool, the shorter the preparation time. Therefore, it is only necessary to control the value of the activity of the molten pool to ensure the antegrade degree of the iron-based amorphous ribbon preparation and improve the quality of the strip.

In this application, the value of γ is 0.5 to 0.95; specifically, the melting pool activity γ is 0.6 to 0.95; more specifically, the melting pool activity γ is 0.75 to 0.85. a is the mass percentage of Al in the molten pool, a≤0.2wt%; b is the mass percentage of C in the molten pool, b≤15wt%.

In a specific embodiment, within the above-mentioned molten pool activity range, the content of Al is a=0.11 wt% to 0.17 wt%; or, the content of C is b=1.0 to 5.0 wt%.

This application also provides a method for preparing an iron-based amorphous ribbon, which includes the following steps:

The molten steel with a certain proportion is sedated, and the sedated molten steel is flowed from the nozzle to the surface of the cooling roll and sprayed to obtain an iron-based amorphous ribbon;

The activity of the molten pool formed by the molten steel flowing from the nozzle to the surface of the cooling roll is shown in formula (I):

γ=(100a) ^b (Ⅰ);

Among them, γ is the melting pool activity, γ=0.5～0.95;

a is the mass percentage of Al in the molten pool, a≤0.2wt%;

b is the mass percentage of C in the molten pool, b≤15wt%.

In the iron-based amorphous ribbon preparation process, the preparation process is no different from the iron-based amorphous ribbon preparation process in the prior art, that is: the molten steel with a specific composition ratio smelted in the smelting furnace is transported to the tundish through the launder The sedated molten steel flows into the nozzle with the slit type opening, and the molten steel sprays the alloy melt from the nozzle slit type opening to the surface of the rotating cooling roll through the above path, so as to obtain the amorphous alloy thin film. band. The molten steel flows from the nozzle to the surface of the cooling roll to form a molten pool, and the molten pool is active directly in the preparation of iron-based amorphous ribbons. In the above process, the heat loss is consistent. Therefore, this application uses the molten pool activity γ=(100a) ^b to represent the molten pool activity, which is essentially the relationship between Al and C in the molten pool and the related performance of the iron-based amorphous ribbon That is, after the relationship between Al and C is determined in a range value, the antegrade and extremely poor quality problems of the iron-based amorphous ribbon can be guaranteed.

The relevant value of the melting pool activity has been described in detail above, and will not be repeated here.

The specific composition of the above-mentioned iron-based amorphous ribbon of the present application is that the content of Fe is 79-83 at%, the content of Si is 6-10 at%, the content of B is 10-14 at%, and the content of C is 0-1.5 at%; The melting pool activity of the iron-based amorphous ribbon in this application is applicable to the iron-based amorphous ribbon well known to those skilled in the art, that is, as long as the composition of the ribbon meets the iron-based amorphous alloy, the melting pool activity is within the range specified in the application Inside, the iron-based amorphous ribbon can be continuously prepared for a long time, and the quality of the iron-based amorphous ribbon can be guaranteed.

After the limitation of the melting pool activity in the iron-based amorphous ribbon preparation process, the continuous preparation time of the iron-based amorphous ribbon of the present application is ≥170min, preferably ≥300min, and can be continuously produced for more than 10 hours without stopping; lamination factor ≥89% .

In order to further understand the present invention, the iron-based amorphous ribbon provided by the present invention will be described in detail below in conjunction with examples, and the protection scope of the present invention is not limited by the following examples.

The specific components of the molten steel for preparing the thin strip in the following embodiments satisfy: the content of Fe is 79-83 at%, the content of Si is 6-10 at%, the content of B is 10-14 at%, and the content of C is 0-1.5 at%.

Example

1) Adjust according to the activity value of the molten pool. Pour the molten steel into the tundish, let it calm for a period of time, and then flow to the top of the crystallizer through the slit nozzle in the spray ladle to prepare the amorphous strip. The strip width is 142mm, 170mm, 213mm, the process parameters and equipment are the same, the prepared thin strips with different melting pool activity characteristics are collected, the process anterograde is judged by the continuous production time of the strip, and the range of the thin strips and the magnetic performance data are tested for comparison. The results are as follows As shown in Table 1～3;

Table 1 Data table of molten pool activity value after adjusting a value

Serial number	a	b	γ	Preparation time (min)	Lamination factor	Very bad
Example 1	0.0011	0.04	0.9154	238	89.28%	1.68
Example 2	0.0013	0.04	0.9216	226	89.05%	1.72
Example 3	0.0015	0.04	0.9269	208	89.12%	1.65
Example 4	0.0017	0.04	0.9315	198	89.17%	1.73

From the analysis in Table 1, it can be seen that only adjusting the value of a to change the activity value of the molten pool, the preparation time of the amorphous ribbon has changed. The greater the activity value of the molten pool, the shorter the preparation time, which is not related to the range and the lamination coefficient. Sex.

Table 2 Data table of molten pool activity value after adjusting b value

Serial number	a	b	γ	Preparation time (min)	Lamination factor	Very bad
Example 1	0.0015	0.03	0.9446	172	89.30%	1.53
Example 2	0.0015	0.05	0.9095	256	89.38%	1.63
Example 3	0.0015	0.07	0.8756	306	89.62%	1.65
Example 4	0.0015	0.09	0.8430	365	89.79%	1.68

It can be seen from the analysis of Table 2 that only the value of b is adjusted to change the activity value of the molten pool. The larger the activity value, the shorter the preparation time of the amorphous ribbon. At the same time, as the value of b increases, the lamination coefficient of the strip increases. , Very poor has an increasing trend.

Table 3 Data table of molten pool activity value after adjustment of values a and b

Serial number	a	b	γ	Preparation time (min)	Lamination factor	Very bad
Example 1	0.00150	0.050	0.9095	256	89.30%	1.63
Example 2	0.00140	0.055	0.8975	278	89.55%	1.69
Example 3	0.00130	0.060	0.8847	293	89.65%	1.71
Example 4	0.00120	0.065	0.8712	323	89.91%	1.75

It can be seen from the analysis of Table 3 that the values of a and b are adjusted to change the activity value of the molten pool. The smaller the activity value, the longer the preparation time of the amorphous ribbon. At the same time, as the value of a decreases and the value of b increases, the strip’s The lamination coefficient has increased, and the range has an increasing trend.

2) Use the b value to adjust the activity value of the molten pool, pour the molten steel into the tundish, let it calm for a period of time, and then flow to the top of the crystallizer through the slit nozzle in the spray ladle to prepare the amorphous strip. The strip width is 142mm , 170mm, 213mm, the process parameters and equipment are the same, the strips are prepared and subjected to heat treatment to test the B value and magnetic properties. The results are shown in Table 4;

Table 4 The magnetic performance test data table of continuously increasing b value to reduce the melting pool activity value

It can be seen from the analysis of Table 4 that if you blindly reduce the activity of the molten pool and increase the activity value, the B value of the strip will decrease, and the higher the loss of the amorphous strip will be, which cannot meet the design requirements and original intention of the amorphous transformer, so it cannot be too much The reduced value.

The description of the above embodiments is only used to help understand the method and core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features disclosed in this document.

Claims (8)

1. An iron-based amorphous ribbon for controlling the activity of the molten pool, characterized in that the activity of the molten pool during the preparation process of the iron-based amorphous ribbon is as shown in formula (I):

   γ=(100a) ^b (Ⅰ);

   Among them, γ is the melting pool activity, γ=0.5～0.95;

   a is the mass percentage of Al in the molten pool, a≤0.2wt%;

   b is the mass percentage of C in the molten pool, b≤15wt%.
2. The iron-based amorphous ribbon according to claim 1, wherein the γ = 0.6 to 0.95.
3. The iron-based amorphous ribbon according to claim 1, wherein the a=0.11 wt% to 0.17 wt%.
4. The iron-based amorphous ribbon according to claim 1, wherein the b=1.0 to 5.0 wt%.
5. A method for preparing an iron-based amorphous ribbon includes the following steps:

   The molten steel with a certain proportion is sedated, and the sedated molten steel is flowed from the nozzle to the surface of the cooling roll and sprayed to obtain an iron-based amorphous ribbon;

   The activity of the molten pool formed by the molten steel flowing from the nozzle to the surface of the cooling roll is shown in formula (I):

   γ=(100a) ^b (Ⅰ);

   Among them, γ is the melting pool activity, γ=0.5～0.95;

   a is the mass percentage of Al in the molten pool, a≤0.2wt%;

   b is the mass percentage of C in the molten pool, b≤15wt%.
6. The preparation method according to claim 1, wherein the continuous preparation time of the iron-based amorphous ribbon is ≥170 min.
7. The preparation method according to claim 1, wherein the content of Fe in the molten steel is 79-83 at%, the content of Si is 6-10 at%, the content of B is 10-14 at%, and the content of C is 0. ~1.5at%.
8. The preparation method according to claim 1, wherein the lamination factor of the iron-based amorphous ribbon is ≥89%.