CN101421423B - Manufacturing method of iron-based amorphous material - Google Patents

Abstract

The present invention provides a method for producing an amorphous material at low cost by efficiently removing Al and Ti that degrade magnetic properties even when inexpensive Fe—B or scrap is used as a raw material of the amorphous material. When manufacturing an iron-based amorphous material that contains 2% to 4% of B, 1% to 6% of Si by mass, and the rest is composed of Fe and unavoidable impurities, Ti in the molten iron after melting the main raw material When the Al concentration or Al concentration is 0.005% by mass or more, an iron oxide source containing 55% by mass or more of iron is added to oxidize and remove both Ti and Al to less than 0.005% by mass. In addition, when the concentration of Ti or Al in the blending of the main raw material is 0.005% by mass or more, an iron oxide source containing 55% by mass or more of iron is charged into the melting vessel together with the main raw material.

Description

Manufacturing method of iron-based amorphous material

technical field

The present invention relates to a method for inexpensively producing iron-based amorphous materials.

Background technique

Amorphous (amorphous) alloys based on the Fe-B-Si system have excellent characteristics as electromagnetic materials. When used as core materials for power transformers, they are comparable to conventional grain-oriented silicon steel sheets. Compared with the latter, it is said that the iron loss becomes about 1/3 of the latter, but its mass production is slower.

The biggest reason is that the price is much higher than that of silicon steel sheet, and the main raw materials such as Fe-B account for more than half of the manufacturing cost.

As a method of inexpensively producing an amorphous material, a method of smelting boron oxide, boric acid, and iron oxide using a carbon-based solid reducing agent such as coke has been proposed (JP-A-58-77509). However, since this method uses carbon as a reducing agent, there is a problem that the C content is higher than the optimum range when direct production is performed with optimum B and Si contents in order to obtain an amorphous material with good magnetic properties.

In order to solve this problem, a method of diluting B and Si with separately manufactured molten steel has been proposed (Japanese Unexamined Patent Publication No. 59-38353) after producing a master alloy with a high B and Si content in which the C content can reach an optimum range. ). However, since this method uses a master alloy with a high B content, the refractory life of the furnace is shortened, the reduction yield of B is reduced, and the unit consumption of raw materials is increased. As its improvement method, a method of making the composition of the master alloy slightly lower in B content and higher in Si content has also been proposed (Japanese Patent Application Laid-Open No. 62-287040 ), but since these methods all use carbon to reduce B, Si, Oxides of Fe, therefore require huge reduction energy, in order to obtain this energy, hot air is used to burn carbon to a high temperature, so refractory materials containing oxides of B, Si, and Fe form molten slag that is easily melted, and there is a cost of refractory materials Substantially increasing the problem.

On the other hand, as the general production method of Fe-B as B raw material, there are methods of refining by the aluminothermic method and the electric furnace method, but the electric furnace method consumes a lot of power, so the power cost is high, and the manufacturing cost of the amorphous material is also low. Increase. In addition, although the aluminothermic method is cheap in production cost, since Al and Ti are mixed into Fe-B, when it is used as a raw material of an amorphous material, the Ti concentration and Al concentration of the produced amorphous material increase. It is known that if the concentration of Ti and Al are increased, the magnetic properties will be lowered, and unless Ti and Al can be removed cheaply, they cannot be used as a raw material of an amorphous material.

In addition, if scraps such as silicon steel sheets can be used as Fe and Si raw materials, the production cost can be reduced, but in this case, due to Al contamination in the scraps, the Al concentration of the amorphous material increases, so it is difficult to use as a raw material for the amorphous material.

Contents of the invention

The object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a solution that can efficiently remove Al and Ti, which degrade the magnetic properties, even when cheap Fe-B and scrap are used as the raw material of the amorphous material. A method by which amorphous materials can be produced inexpensively.

In order to solve the above-mentioned problems, the gist of the present invention is as follows.

(1) A method for producing an iron-based amorphous material, characterized in that, in the production process, it contains 2% to 4% of B and 1% to 6% of Si by mass, and the balance is composed of Fe and unavoidable impurities. In the case of iron-based amorphous materials, when the Ti concentration or the Al concentration in the molten iron after melting the main raw material is 0.005% by mass or more, an iron oxide source containing 55% by mass or more of iron is added, and Ti and Al are uniformly mixed. Oxidation is removed to less than 0.005% by mass.

(2) A method for producing an iron-based amorphous material, characterized in that, during the production process, it contains 2% to 4% of B and 1% to 6% of Si by mass, and the balance is composed of Fe and unavoidable impurities. In the case of an iron-based amorphous material, when the concentration of Ti or Al in the blending of the main raw material is 0.005% by mass or more, an iron oxide source containing 55% by mass or more of iron is charged in advance together with the main raw material. Melting container.

(3) The method for producing an iron-based amorphous material according to (1) or (2), wherein, by mass, 0.001% to 3% of C and 0.008% to 0.15% of P are contained. one or two.

(4) The method for producing an iron-based amorphous material according to any one of (1) to (3), wherein, by mass, one of Co, Ni, or Cr of 6% or less Or more than 20% of the amount of Fe replaced by two or more.

Description of drawings

FIG. 1 is a graph showing changes with time in the concentration of Ti in molten iron when an iron oxide source is added to molten iron of an amorphous base material.

Fig. 2 is a graph showing changes with time in the concentration of Al in molten iron when an iron oxide source is added to molten iron of an amorphous base material.

Detailed ways

The inventors of the present invention have found from experiments using a small melting furnace that Ti and Al can be efficiently oxidized and removed by adding iron oxide when melting an iron-based amorphous base material. Since Ti and Al are oxidized preferentially over B and Si which are the main components of the amorphous base material, they are not oxidized and removed without excessively reducing the utilization ratio of B and Si.

As one of the embodiments of the invention, a melting furnace is used to melt the main raw material blended so that the required B and Si components are obtained, and when molten iron is generated, an iron oxide source containing 55% by mass or more of iron is added, Ti and Al are oxidized and removed.

In a small-scale experiment, molten iron containing 3.2% by mass of B and 1.8% by mass of amorphous base metal was produced in a melting furnace, and after heating up to 1500°C, 50 kg of various irons were added per 1 ton of molten iron. The changes of Ti and Al concentration in molten iron with time in the case of iron oxide source are shown in Fig. 1. It can be seen that in the case of any iron oxide source having an iron content concentration of 55% or more, Ti and Al are reduced to less than 0.005% by mass, which has no influence on magnetic properties. However, the lower the iron content concentration and the iron oxide source with more miscellaneous ore components other than iron oxide, the lower the oxidation removal rate of Ti and Al. On the other hand, when steelmaking dust having an iron concentration of less than 55% was used as an iron oxide source, the oxidative removal rate of Ti and Al was extremely slow, and Ti was not reduced to less than 0.005% by mass. Considering the necessary addition amount of iron oxide source, refining time, slag treatment cost due to increase in the amount of slag generated from miscellaneous ores, etc., it is found that the effect is relatively low as the iron concentration is not 55% or more. Small.

In addition, the retention time after refining the iron oxide source also depends on the amount of the iron oxide source used, but it is preferable to ensure 15 minutes or more.

In addition, as another way of implementing the invention, the iron oxide source containing more than 55% by mass of iron and the main raw material mixed so as to achieve the required B and Si components are preliminarily charged into a melting furnace and melted. , to generate the molten iron of the base metal. In the above-mentioned mode of adding the iron oxide source after the molten iron is produced, since dust is generated during the addition, this mode is preferable when the dust collection capability of the melting furnace is insufficient.

In the above-mentioned small-scale experiment, various iron oxide sources with a mass of 50 kg per ton of molten iron were added to the melting furnace in advance, and the concentrations of Ti and Al in the molten iron after melting together with the main raw materials are shown in Table 1. The temperature after 10 minutes of complete melting is 1370 to 1380°C. If Ti and Al are not removed, the concentration should be the same as the initial value in Fig. 1, but an iron oxide source with an iron concentration of 55% or more is used. In the case of both, the concentration becomes less than 0.005% by mass, and it can be seen that Ti and Al are oxidized and removed in the melting stage. Since Ti and Al are oxidized and removed during the melting stage, the refining is completed within the time when the raw material is melted and heated to the temperature required for tapping. On the other hand, when an iron oxide source having an iron content concentration of less than 55% is used, the Ti concentration is 0.005% by mass or more.

The component composition and its range in this invention are demonstrated. In addition, unless otherwise specified, the range of a component composition is mass %.

B is an element effective in improving the amorphous forming ability and thermal stability, and can be added in an appropriate amount according to the requirements of each characteristic. When B is less than 2%, an amorphous phase cannot be obtained stably, and when it exceeds 4%, it is difficult to form an amorphous phase due to an increase in the melting point.

Si is also an element effective in improving the amorphous forming ability and thermal stability, and can be added in an appropriate amount according to the requirements of each characteristic. When Si is less than 1%, the amorphous phase cannot be stably formed, and when it is more than 6%, the effect of improving the thermal stability is saturated.

C is an element effective in improving the magnetic flux density of the ribbon and improving the ability to form amorphous (improvement in castability), and its content can be determined in an appropriate amount according to the requirements of each characteristic. When C is contained in an amount of 0.001% or more, preferably in an amount of 0.003% or more, the wettability between the melt and the cooling substrate is improved, and a good ribbon can be formed. In addition, when C is preferably 0.01% or more, an effect of improving the ability to form amorphous can be obtained. On the other hand, when it exceeds 3%, the effect of improving the magnetic flux density decreases.

P is an element effective in improving iron loss and amorphous forming ability, and may be contained in an appropriate amount according to the requirements of each characteristic. Iron loss and amorphous formation ability are improved by containing P, and the allowable amount of impurity elements is increased. However, when P is less than 0.008%, the improvement effect of amorphous formation ability and iron loss improvement effect is not seen, and the expansion of impurities does not appear. The effect of the tolerance of the elements Mn and S. On the other hand, as the content of P increases, cracks in the ribbon tend to propagate and the workability deteriorates, so it is preferably 0.15% or less.

In addition, in the composition of the present invention, even for the purpose of improving the characteristics of magnetic flux density and corrosion resistance, annealing conditions, etc., it is replaced by one or two or more selected from Co, Ni, or Cr of 6% or less. Even when a part of Fe, that is, 20% or less of the amount of Fe, the effects of the present invention are not particularly impaired. However, although Co and Ni have the effect of improving the magnetic flux density, they are expensive, so considering the cost of raw materials, they are preferably limited to 10% or less of the amount of Fe to be substituted, more preferably 5% or less of the amount of Fe to be substituted.

In addition, in the composition of the present invention, as constituent elements, in addition to Fe, B, Si, C, P, Ni, Co, Cr, well-known N, Ti, Zr, V, Nb, Mo, Cu, etc. are also included. The effect of the present invention is not impaired at all.

Table 1

Furthermore, as a result of investigating the influence of molten iron temperature, it was found that if the temperature is higher than the melting point of the base metal, Ti and Al will become less than 0.005% by mass, but the higher the temperature, the higher the oxidation efficiency of Ti and Al, and the higher the temperature, the higher the oxidation efficiency of Ti and Al. The final concentrations of B and Al are also reduced, while the utilization of B and Si is increased. On the other hand, the higher the temperature, the more electric energy is required for melting, and the cost of refractory materials for the melting furnace also increases. Therefore, it is preferable to lower the molten iron temperature at a level capable of achieving the desired oxidation removal amount of Ti and Al.

Example

Hereinafter, the present invention will be specifically described based on specific examples.

Example 1

Oxidative refining of Ti and Al was performed using a 3-ton high-frequency melting furnace to generate molten iron from an amorphous base material. As main raw materials, inexpensive electrical steel scrap and Fe-B having the composition shown in Table 2 were used, and a small amount of Fe-Si was used for Si concentration adjustment. The unit consumption of the compounding quantity is also shown in Table 2.

Table 2

(quality%)

Si B Ti al Compounding amount (kg/t) Electromagnetic steel shavings 1.59 0.002 0.002 0.037 825.0 Fe-B 0.49 19.89 0.20 0.058 168.4 Fe-Si 74.9 - - - 6.6 Composition 1.89 3.35 0.035 0.040 1000.0

After the main raw material was melted, the temperature of the molten iron was raised to 1500°C. The invention, for example, as shown in Table 3, was added with the same iron ore (Mount Newman iron ore) as the raw material used in the small-scale experiment. ): iron content 65% by mass), steelmaking dust (dust during decarburization treatment: iron content 64% by mass), sintered ore (iron content 58% by mass) 150kg (50kg/t), and tapped after 20 minutes . Also for the purpose of improving properties, the same refining operation was carried out by adding C, P, Co, Ni, and Cr to the main raw materials, so that the molten iron composition after melting contained 0.001% to 3% of C and 0.008% -0.15% of one or two of P, or 20% or less of Fe is replaced by one or two or more of Co, Ni, or less than 6% of Cr. In addition, as a comparative example, 150 kg of steelmaking dust (dust at the time of pretreatment of molten iron: iron content 53 mass %) or a mixture of steelmaking dust and slag was added with the same method. deal with.

Table 4 shows the composition of the molten iron sampled immediately before adding the iron oxide source and the composition of the molten iron immediately before tapping. It can be seen that in the invention example using an iron oxide source with an iron content of 55% by mass or more, the concentrations of Ti and Al are both reduced to less than 0.005% by weight, which has no influence on the magnetic properties, and the oxidation loss of B and Si is also small. There is a utilization rate of more than 95%. In addition, even in the case of containing one or both of 0.001% to 3% of C and 0.008% to 0.15% of P, one or more of Cr selected from Co, Ni, or 6% or less Even when substituting two or more kinds of a part of Fe, that is, 20% or less of the amount of Fe, this effect is not impaired. On the other hand, in the comparative example using an iron oxide source with an iron content of less than 55% by mass, the Ti concentration or Al concentration was 0.005% by mass or more, although the utilization rates of B and Si were at the same level.

Example 2

Using the same amount of the same raw material as that used in Example 1, an iron oxide source having an iron content of less than 55% by mass as shown in Table 5 before melting was charged into a 3-ton-scale high-frequency melting furnace and melted. . When about 10 minutes have elapsed since the raw materials have completely melted, the temperature measurement and the sampling of the molten iron are carried out, and the sampling is carried out again after the temperature rises to 1500°C and the steel is tapped. For the purpose of improving the properties, the same refining operation was carried out by adding C, P, Co, Ni, Cr to the main raw materials, so that the molten iron composition after melting contained 0.001% to 3% of C and 0.008% -0.15% of one or two of P, or 20% or less of Fe is replaced by one or two or more of Co, Ni, or less than 6% of Cr. In addition, as a comparative example, melting in the case of using an iron oxide source having an iron content of less than 55% by mass as shown in Table 4 was performed by the same method.

The composition of molten iron after complete melting and the composition immediately before tapping are also shown in Table 6. In the invention example using an iron oxide source with an iron content of 55% by mass or more, the concentrations of Ti and Al are reduced from the stage where the raw materials are completely melted to below 0.005% by mass, which has no effect on magnetic properties. , Al concentration is further reduced. It can also be seen that the oxidation loss of B and Si is also small, and the material utilization rate of the composition before tapping relative to the compound composition is 92% or more. In addition, in the case of containing one or both of 0.001% to 3% of C and 0.008% to 0.15% of P, one or both of Co, Ni, or Cr of 6% or less Even when substituting a part of Fe, that is, 20% or less of the amount of Fe with more than one species, this effect will not be impaired. On the other hand, in the comparative example using an iron oxide source with an iron content of less than 55% by mass, the Ti concentration or Al concentration was 0.005% by mass or more, although the utilization rates of B and Si were at the same level.

Industrial Utilization Possibility

According to the present invention, even when inexpensive Fe—B or scrap is used as a raw material of an amorphous material, an amorphous material can be produced inexpensively by efficiently removing Al and Ti that degrade magnetic properties.

In the present invention, "above" and "below" indicating a numerical range both include the original number.

Claims (5)

1. the method for manufacture of an iron-base amorphous material; It is characterized in that; Contain 2%～4% B, 1%～6% Si in mass making, during iron-base amorphous material that its surplus is made up of Fe and unavoidable impurities, Ti concentration or Al concentration are under the situation more than the 0.005 quality % in the iron liquid after melting main raw material; Add and to contain agglomerate, iron ore or the steel-making dust that the above iron of 55 quality % divides, with Ti and the equal oxidation of Al except that going to less than 0.005 quality %.

2. the method for manufacture of an iron-base amorphous material; It is characterized in that; Contain 2%～4% B, 1%～6% Si in mass in manufacturing; During iron-base amorphous material that its surplus is made up of Fe and unavoidable impurities, the concentration that contains of Ti or Al is under the situation more than the 0.005 quality % in the cooperation of main raw material, will contain agglomerate, iron ore or steel-making dust and the main raw material that the above iron of 55 quality % divides and together be encased in the melting vessel in advance.

3. the method for manufacture of iron-base amorphous material according to claim 1 and 2 is characterized in that, said iron-base amorphous material also contains one or both among the P of 0.001%～3% C and 0.008%～0.15% in mass.

4. the method for manufacture of iron-base amorphous material according to claim 1 and 2 is characterized in that, said iron-base amorphous material is in mass by below 20% of one or more replacement of fe amounts among the Cr below Co, Ni or 6%.

5. the method for manufacture of iron-base amorphous material according to claim 3 is characterized in that, said iron-base amorphous material is in mass by below 20% of one or more replacement of fe amounts among the Cr below Co, Ni or 6%.

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