JP4593313B2 - Fe-Ni-based magnetic alloy plate excellent in hot workability and manufacturing method thereof - Google Patents

Description

The present invention relates to a Fe-Ni magnetic alloy plate used for a magnetic head, a magnetic shield material, a wound core of a transformer core, and the like, and a manufacturing method thereof, in particular, with improved hot workability without impairing magnetic properties. An Fe-Ni magnetic alloy plate and an advantageous manufacturing method thereof are proposed.

  Fe-Ni alloys are permalloys specified in JIS C2531, PD materials (Ni: 30-40 mass%), PB materials (Ni: 40-50 mass%), PC materials (Ni: 70-85 mass%), etc. Is well known. The PB material is often used for a stator of a watch, a pole piece of an electromagnetic lens, or the like by taking advantage of a characteristic that a saturation magnetic flux density is large. On the other hand, PC materials are used for magnetic shield materials, magnetic heads, and the like by taking advantage of excellent relative magnetic permeability.

  Conventionally, there have been proposals for techniques for improving the magnetic properties of Fe-Ni magnetic alloys. For example, Patent Document 1 discloses that the magnetic characteristics are improved by a method in which {200} planes including the easy magnetic axis <100> are integrated in-plane with an integration strength ratio of 2 or more.

  In Patent Document 2, in view of the influence of impurities or precipitates on the magnetic properties of the Fe—Ni-based magnetic alloy, S, B, and O, which are impurity elements, are defined as S ≦ 0.003 mass% and B ≦ 0.005 mass%. And there is a proposal to regulate O ≦ 0.005 mass% and S + B + O ≦ 0.008 mass%. This technique is based on the premise that the second phase such as precipitates adversely affects the domain wall motion, and suppresses the impurity element. However, this technique is not a technique for directly controlling the nonmetallic inclusion itself.

Furthermore, in Patent Document 3, in view of the influence of impurities or inclusions on the magnetic properties of Fe-Ni magnetic alloys, oxygen and sulfur that form oxide-based nonmetallic inclusions and sulfide-based nonmetallic inclusions are disclosed. A technique has been disclosed that facilitates domain wall movement and improves magnetic properties by making the total concentration 150 ppm or less. However, this technique is a technique for improving magnetic properties by performing deoxidation and / or desulfurization and controlling the composition of inclusions, and is not a disclosure of a method for improving hot workability.
Japanese Patent Laid-Open No. 5-5162 JP-A-6-122947 JP 2002-161328 A

In general, Fe-Ni magnetic materials have poor workability, and large cracks are likely to occur at the side edge of the plate, especially during hot rolling, so it is common to perform trimming to cut off the side edge. Therefore, there was a problem that the product yield was poor. In this regard, the inventions disclosed in Patent Documents 1 to 3 described above are based on the idea of improving hot workability without deteriorating the magnetic properties of Fe-Ni based magnetic alloys, particularly nonmetallic inclusions in the alloys. There is no disclosure of an Fe—Ni-based magnetic alloy plate and a method for manufacturing the same, in which both of the above characteristics are excellent through the composition and morphology control.

Therefore, a main object of the present invention is to propose an Fe—Ni based magnetic alloy plate that is excellent not only in magnetic properties but also in hot workability.
Another specific object of the present invention is to improve the above-mentioned two characteristics together without sacrificing other characteristics through the control of the composition of inclusions and the form thereof.
Still another specific object of the present invention is to propose a method for increasing the productivity by advantageously proceeding with deoxidation and desulfurization with Si or Al.

To realize the above object, the present invention provides C: 0.001 to 0.2 mass%, Si: 0.01 to 0.5 mass%, Mn: 0.01 to 1.0 mass%, S: 0.0001 to 0.002 mass%, Ni: 30 to 85 mass%. , Al: 0.001 to 0.1 mass%, Mg: 0.0002 to 0.05 mass%, Ca: ≦ 0.0020 mass% and O: 0.0002 to 0.01 mass%, and an alloy plate having a component composition composed of the remaining Fe and inevitable impurities. In addition , in this alloy plate, at least within the range of the component composition, the main component is one or two of Al ₂ O ₃ and MgO of 75 mass% or more, SiO ₂ ≦ 10 mass%, CaO ≦ 10 mass. % Of oxide inclusions and / or sulfide inclusions having a size of 0.5 μm or more in a vertical cross section parallel to the rolling direction. Suggest Fe-Ni based magnetic alloy sheet excellent in hot workability, characterized in that it comprises 300 pieces / mm ^2.

Moreover, this invention is a method of manufacturing the Fe-Ni type magnetic alloy plate of any one of Claims 1-5 , Comprising: The molten metal of the Fe-Ni type alloy which performed primary refining is used for magnesia. After oxidative smelting in a secondary smelting vessel of either AOD or VOD with a lining refractory, it is first removed, and then one or more of limestone, fluorite, and silica Of CaO—Al ₂ O ₃ —MgO—SiO ₂ —F system slag is added, and then Al and / or Si is introduced into the molten alloy, Al: 0.001 to 0.1 mass%, Si: Deoxidized and desulfurized by preparing 0.01 to 0.5 mass% to obtain a molten alloy having O 2 : 0.0002 to 0.01 mass%, S: 0.0001 to 0.002 mass%, and then continuously casting this molten alloy We propose a method for producing Fe-Ni magnetic alloy sheets with excellent hot workability, characterized by surface rolling and hot rolling after forming a slab. I plan.

In the above-mentioned alloy of the present invention, in addition to the above components, one or more selected from Mo, Cu, Co and Nb are each 15 mass% or less and a total range of 20 mass% or less. In this alloy, at least within the range of the component composition, the main component is Al ₂ O ₃ , any one or two of MgO is 75 mass% or more, SiO ₂ ≦ 10 mass%, Alloy containing CaO ≦ 10 mass% , Ni containing 35 mass% or more and less than 40 mass%, maximum relative permeability μm: 50,000 or more, initial relative permeability μi: 10,000 or more, and coercive force Hc: An alloy containing 4 [A / m] or less, Ni containing 40 mass% to 50 mass%, maximum relative permeability μm: 100,000 or more, initial relative permeability μi: 10,000 or more Magnetic force Hc: Magnetic properties of 4 [A / m] or less, alloy containing 70 to 85 mass% of Ni, and maximum relative permeability It is an effective means to exhibit magnetic characteristics of a rate μm: 200,000 or more, an initial relative permeability μi: 100,000 or more, and a coercive force Hc: 0.8 [A / m] or less.

As described above, according to the present invention, it is possible to propose an Fe—Ni-based magnetic alloy plate that exhibits excellent hot workability and also exhibits excellent magnetic properties.
In addition, according to the present invention, the manufacturing of the alloy can be easily performed through a mass production line of stainless steel or the like, so that the manufacturing cost can be reduced.

In order to develop the present invention, the present inventors conducted the following experiments. That is, in this experiment, a Fe-Ni alloy equivalent to Permalloy C (77.4 mass% Ni-4 mass% Mo-4.7 mass% Cu-balance Fe) was melted using a 10 kg high-frequency induction furnace, and the molten alloy was placed on the molten alloy. CaO—SiO ₂ —Al ₂ O ₃ —MgO—F slag that was previously dissolved and homogenized was added. Thereafter, Al and / or Si were added to perform deoxidation and desulfurization. At this time, the Al concentration was changed from 0 mass% to 0.5 mass%. The molten alloy thus obtained was cast into a mold to obtain an ingot. The ingot was forged and hot rolled, and then further cold rolled to obtain a cold rolled sheet having a thickness of 0.5 mm. This cold-rolled sheet having a thickness of 0.5 mm was magnetically annealed under a hydrogen atmosphere at 1100 ° C. for 3 hours to measure the magnetic properties. Moreover, about hot workability, the presence or absence of the crack of the side edge of a hot rolled sheet was evaluated.

As a result of the above experiment, the following became clear. It was found that as the Al concentration increased, desulfurization progressed and the S concentration decreased and at the same time the Mg concentration increased. This is presumably because MgO in the slag is reduced according to the following formula (1).
3 (MgO) + 2Al = 3Mg + (Al ₂ O ₃ ) …… (1)
It has also been clarified that the Mg and S concentrations play an important role in hot workability and magnetic properties. That is, when the Al concentration is low and the S concentration is high, both hot workability and magnetic properties are lowered, and the required properties cannot be obtained. Conversely, it was found that when the Al concentration is high, the low S concentration is low, and the Mg concentration is high, the hot workability tends to decrease.

The reason why this phenomenon occurs is as follows. First, at low Al concentration, high S concentration, and low Mg concentration, S exists as solid solution [S] and (MgS). Since the solid solution [S] embrittles the grain boundary of the metal, the hot workability is deteriorated, and (MgS) inhibits the movement of the domain wall, thereby deteriorating the magnetic properties. Moreover, in the case of a low Al concentration, the O concentration increases, and the amount of oxide inclusions as well as sulfides increases, which causes a decrease in magnetic properties. The composition of the inclusions is also no longer a high-melting inclusions represented by _{Al 2 O 3, MgO · Al} 2 O 3, MgO, SiO 2 becomes a low-melting silicate principal. The inclusions extend during hot rolling and are divided during cold rolling, which also impedes domain wall movement, which further degrades magnetic properties.

On the other hand, at high Al concentration, low S concentration, and high Mg concentration, there is no obstructive factor for magnetic properties, but low melting point intermetallic compounds such as Ni ₂ Mg are formed, leading to a decrease in hot workability. Conceivable.

  The present invention is based on the above-mentioned knowledge, under the selection of an appropriate Al concentration and an appropriate slag composition, by appropriately controlling the concentration of S and Mg that change in conjunction with these, to achieve hot workability While solving the problem of the conventional austenite single-phase structure that is scarce, it was possible to obtain a product with excellent magnetic properties and good yield.

  Hereinafter, each condition in the alloy which concerns on this invention, and its manufacturing method is demonstrated in detail. First, the component composition recommended in this alloy will be described.

C: 0.001 ~ 0.2mass%
C is an element necessary for maintaining the strength of the alloy. If the amount of C is less than 0.001 mass%, sufficient strength cannot be obtained. On the other hand, if it exceeds 0.2 mass%, carbide is formed or solid solution C increases, so that crystal grain growth and domain wall movement occur. To prevent magnetic properties from deteriorating. Therefore, the C content is defined as 0.001 to 0.2 mass%. Preferably it is 0.002-0.02 mass%.

Si: 0.01-0.5mass%
Si is an element effective for deoxidation. If the amount of Si is less than 0.01 mass%, a sufficient deoxidation effect cannot be obtained. On the other hand, when it exceeds 0.5 mass%, the regular lattice is not in an optimum state, and the magnetic properties are deteriorated. Therefore, the content of Si is defined as 0.01 to 0.5 mass%. Preferably, it is 0.02-0.3 mass%, More preferably, it is 0.03-0.15 mass%.

Mn: 0.01-1.0mass%
Mn is an effective element for controlling the formation of ordered lattices. If the amount of Mn is less than 0.01 mass% or exceeds 1.0 mass%, the ordered lattice is not in an optimal state and deteriorates the magnetic properties. Therefore, it is desirable to add an appropriate amount. Further, Mn is a useful element from the viewpoint of bonding with S that lowers hot workability, forming MnS to make harmless effects of S harmless, and improving punching workability. Therefore, the Mn content is defined as 0.01 to 1.0 mass%. Preferably it is 0.1-0.8 mass%, More preferably, it is 0.2-0.7 mass%.

S: 0.0001 to 0.002 mass%
S is a desirable element because it lowers hot workability. However, S forms MgS and MnS particles by combining with Mg and Mn, so when punching a thin plate into various shapes. It is also an element that helps to improve its workability. If the amount of S is less than 0.0001, the required punchability cannot be ensured. On the other hand, when S exceeds 0.002 mass%, the amount of solid solution S increases and the hot workability is deteriorated, so that the hot rolled sheet is cracked and the yield of the product is deteriorated. Therefore, the S content is defined as 0.0001 to 0.002 mass%. In addition, Preferably, it is 0.0002-0.0018 mass%. More preferably, it is 0.0003-0.0015 mass%.

Al: 0.001 to 0.1 mass%
Al is a deoxidizing element and plays an extremely important role in the present invention. If the amount of Al is less than 0.001 mass%, deoxidation is not sufficient, so that the O concentration exceeds 0.01 mass% and the S concentration exceeds 0.002 mass%. Therefore, the number of oxide-based and sulfide-based inclusions exceeds 300 / mm ^2, which causes deterioration of magnetic characteristics. In addition, when the solid solution S is high, the grain boundaries are embrittled, which adversely affects hot workability. On the other hand, when the Al content exceeds 0.1 mass%, the power to reduce MgO in the slag becomes too strong, and Mg in the steel exceeds 0.05 mass%. As a result, a low-melting intermetallic compound Ni ₂ Mg is formed, which adversely affects hot workability. In addition, in this case, O becomes as low as less than 0.0002 mass%, CaO in the slag is reduced, and Ca exceeds 0.002 mass%. For these reasons, Al is defined as 0.001 to 0.1 mass%. Preferably, it is 0.002-0.02 mass%, More preferably, it is 0.003-0.015 mass%.

Mg: 0.0002 ~ 0.05mass%
Mg combines with S, which decreases hot workability, to form MgS, and is required as an element for improving hot workability and punching workability. If the amount of Mg is less than 0.0002 mass%, S that lowers hot workability cannot be sufficiently fixed as MgS, so hot workability is lowered. On the other hand, when it exceeds 0.05 mass%, the low-melting intermetallic compound Ni ₂ Mg is formed, so that the hot workability is also lowered. Therefore, Mg was defined as 0.0002 to 0.05 mass%. Preferably, it is 0.001-0.02 mass%, More preferably, it is 0.002-0.01 mass%.
As for the method of adding Mg, it is preferable to reduce from slag by effectively using Al as shown in the formula (1). Of course, a method of adding an appropriate amount of metal Mg directly may be used.

Ca: ≦ 0.0020 mass%
Ca is an element effective in reducing weldability. When the amount of Ca exceeds 0.0020 mass%, black spots and the like are generated during welding, and the weldability is remarkably deteriorated. Therefore, the Ca content is specified to be 0.0020 mass% or less. Preferably, it is 0.0015 mass% or less.

O: 0.0002 to 0.01 mass%
O forms oxide inclusions with other elements, and if the amount is too large, the magnetic properties are deteriorated. Therefore, it is desirable that O be as low as possible from this viewpoint. However, if it is too low, it becomes a strong reducibility, reducing CaO in the slag and increasing the Ca concentration in the molten steel, so it is an element that needs to be controlled. That is, if the amount of O is less than 0.0002, it becomes strongly reducing and reduces CaO in the slag, so that the Ca concentration in the molten steel exceeds 0.0020 mass%, and at the same time, the oxide inclusions are reduced and the necessary punching is performed. Workability cannot be obtained. On the other hand, if the amount of O exceeds 0.01 mass%, the number of oxide inclusions increases, and magnetic properties are deteriorated because the movement of the domain wall is disturbed. At the same time, a low melting point silicate mainly composed of SiO ₂ is generated and fine. Distributed. As a result, the movement of the domain wall is hindered and the magnetic properties are adversely affected. Moreover, some oxygen exists also as solid solution oxygen, and reduces hot workability. Therefore, the content of O is defined as 0.0002 to 0.01 mass%. Preferably, it is 0.0003 to 0.007 mass%, more preferably 0.0004 to 0.002 mass%.

Mo: 15 mass% or less
Mo is an effective component for producing the magnetic properties of the PC material under practical production conditions, and has a function of controlling the conditions for generating a regular lattice that affects the magnetocrystalline anisotropy and magnetostriction. The ordered lattice is affected by the cooling conditions after magnetic annealing, and if it does not contain Mo, a very fast cooling rate is required, but by including a certain amount of Mo, it is the maximum in industrially practical cooling conditions. Characteristics can be obtained. However, if the amount of Mo is too large, the optimum cooling rate becomes too slow, the Fe content decreases, and the saturation magnetic flux density decreases. For this reason, the Mo content is specified to be 15 mass% or less.

Cu: 15 mass% or less
Cu, like Mo, mainly has the function of controlling the generation conditions of the regular lattice of PC material, but stabilizes the magnetic properties by reducing the influence of the cooling rate on the effect of Mo. There is an effect. It has also been found that the addition of an appropriate amount of Cu improves the magnetic properties under alternating current because it increases the electrical resistance. However, if the amount of Cu is too large, the Fe content decreases and the saturation magnetic flux density decreases. For this reason, Cu content is prescribed | regulated as 15 mass% or less.

Co: 15 mass% or less
Co has the function of increasing the magnetic flux density and improving the relative permeability by adding an appropriate amount. However, if the Co content is too large, the relative magnetic permeability is decreased, and at the same time, the Fe content is decreased and the saturation magnetic flux density is decreased. For this reason, the Co content is specified to be 15 mass% or less.

Nb: 15 mass% or less
Nb has little effect on the magnetic properties, but increases the hardness of the material and improves the wear resistance, so it is an indispensable component for applications such as magnetic heads. It is also effective for reducing deterioration of magnetic characteristics due to mold formation. However, if the amount of Nb is too large, the Fe content decreases and the saturation magnetic flux density decreases. For this reason, the Nb content is preferably 15 mass% or less, particularly preferably 1 to 15 mass%.

In the alloy according to the present invention, a part of the above components and oxygen combine to form oxide inclusions, but the preferred composition thereof is any one or two of Al ₂ O ₃ and MgO. It consists of 75 mass% or more, SiO ₂ ≦ 10 mass%, and CaO ≦ 10 mass%.

One or two of Al ₂ O ₃ and MgO: 75 mass% or more If the oxide inclusions have a low melting point of about 1000 to 1200 ° C, they are stretched during hot working, and further cold Since it is finely divided in the rolling stage, the density of inclusions is increased in the final product and the magnetic properties are deteriorated. Therefore, in order to prevent the oxide inclusions from being stretched during hot rolling, the inclusion of one or two of Al ₂ O ₃ and MgO should be 75 mass% or more. It is valid. The reason is that both Al ₂ O ₃ and MgO have a high melting point of 2000 ° C or higher, and at the same time, these two oxide compounds MgO-Al ₂ O ₃ also have a high melting point of 2000 ° C or higher. From that.
The amounts of Al ₂ O ₃ and MgO are preferably 80 mass% or more, more preferably 85 mass% or more.

SiO ₂ ≦ 10 mass%, CaO ≦ 10 mass%
The amount of SiO ₂ and CaO was specified to be 10 mass% or less because the melting point of inclusions was about 1200 ° C. when these amounts exceeded 10 mass%. Preferably, it is 8 mass% or less.

  Furthermore, in the present invention, by configuring as described above, while maintaining the required magnetic properties, on the other hand, by controlling the number of oxide inclusions and / or sulfide inclusions, It is important to ensure the necessary hot workability. The reason for limiting the number of inclusions will be described below.

Total amount of oxide inclusions and / or sulfide inclusions: 50 to 300 / mm ²
Controlling the number of oxide inclusions and sulfide inclusions is very important in the present invention. For example, it is considered that high magnetic properties can be obtained if the number of these inclusions is small. In this case, however, since part of O and S are dissolved in the alloy, hot workability is deteriorated. Therefore, if the total amount of oxide inclusions and sulfide inclusions is less than 50, the solid solution amount of O and S increases, hot workability decreases, and the production yield decreases. The punching workability is also reduced. On the other hand, when the number exceeds 300, the magnetic properties are deteriorated in order to prevent the domain wall from moving. For this purpose, the total amount of oxide inclusions and sulfide inclusions was set to 50 to 300 / mm ² . Preferably, it is 60 to 180 pieces / mm ² . The sulfide inclusions mentioned here are not particularly limited, but are either or both of MgS and MnS.

The oxide inclusions are formed during deoxidation, whereas sulfide inclusions are formed during or after solidification. Therefore, in order to effectively form sulfide inclusions according to the reactions of the following formulas (2) and (3) and to fix S, the time during which the slab surface temperature is exposed to 800 ° C. or more during continuous casting It is desirable to hold for at least 3 minutes.
Mg + S → MgS (2)
Mn + S → MnS (3)

Next, among the Fe—Ni based magnetic alloy plates according to the present invention, the magnetic characteristics required for the PD material (Ni of 35 mass% or more and less than 40 mass%) are those showing the following characteristics in a preferred embodiment. is there.
1. High permeability: at least maximum relative permeability μm = 50,000 or more, initial relative permeability μi = 10,000 or more,
2. Small coercive force: at least coercive force Hc = 4 [A / m] or less,

In addition, among the Fe-Ni based magnetic plywood according to the present invention, the magnetic properties required for the PB material (40 mass% or more 50 mass% or less Ni), which exhibits the following characteristics is a preferred embodiment .
1. High permeability: at least maximum relative permeability μm = 100,000 or more, initial relative permeability μi = 10,000 or more,
2. Small coercive force: at least coercive force Hc = 4 [A / m] or less,

And among the Fe-Ni type magnetic alloy plates according to the present invention, with respect to the magnetic properties of the PC material (70 to 85 mass% Ni), it is preferable to further improve the permeability and reduce the coercive force. That is, the target numerical values are the maximum relative permeability μm = 200,000 or more, the initial relative permeability = 100,000 or more, and the coercive force Hc = 0.8 [A / m] or less.

Next, in the present invention, the above alloy is manufactured by a secondary refining method using AOD or VOD, and a method of manufacturing at a lower cost than in the case of using a vacuum induction furnace or the like is proposed. That is, in the present invention, iron scrap, nickel, ferronickel or the like is used as a raw material, and this is used in a predetermined Fe—Ni composition (PD material: Fe-36 mass% Ni, PB material: Fe-46 mass% Ni, PC material). : Fe-77mass% Ni) and melt in a 60-ton electric furnace. As this raw material, scraps of an Fe—Ni based magnetic alloy plate may be used. Thereafter, the molten alloy melt is transferred to AOD or VOD and subjected to oxidative refining for treatment such as decarburization, dechromation, and dephosphorization. A refractory containing magnesia represented by dolomite is used as the refractory for AOD and VOD. After that, it is removed once, and flux such as limestone, fluorite, silica sand, etc. is newly added during this AOD or VOD, and CaO-SiO ₂ -Al ₂ O ₃ -MgO-F slag is put on the molten metal. Form. MgO in the slag can also be obtained by melting the refractory into the slag. Of course, waste bricks containing MgO in advance may be used. Thereafter, the molten alloy is desulfurized and deoxidized using Al and / or FeSi alloy, and by adjusting Al to 0.001 to 0.1 mass% and Si to 0.01 to 0.5 mass%, O is 0.0002 to 0.01 mass%. , S was 0.0001 to 0.002 mass%.

In the molten metal having such a slag composition and Al concentration, Si concentration, and oxygen concentration, the composition of oxide inclusions in the molten alloy is 75 mass% or more when either one or two of Al ₂ O ₃ and MgO are used. , SiO ₂ ≦ 10 mass% and CaO ≦ 10 mass%. According to the formula (1), the added Al reduces MgO in the slag, supplies Mg into the molten steel, and the Mg, Al, Si, and Ca concentrations in the molten steel are Al ₂ O ₃ and MgO. This is because it is controlled within a range appropriate for forming the main inclusion, that is, a range defined by the present invention. In some cases, a predetermined amount of Mo or Cu may be added after deoxidation. Although it does not specifically limit as a Mo source, As for metal Mo or Fe-Mo, Cu, it is desirable to use metal Cu. Some PC materials were also manufactured without Cu. After AOD or VOD, the temperature may be adjusted with LF, or more precise component adjustment may be performed.

  The molten alloy refined in this manner is cast by a continuous casting machine to produce a continuous cast slab. At this time, since the sulfide inclusions are formed during or after solidification, there is no particular limitation in order to effectively form sulfide inclusions and fix S. It is desirable to keep the time at which the surface temperature is exposed to 800 ° C. or more for 3 minutes or more.

Raw materials such as iron scrap, nickel, ferronickel, etc., in a 60-ton electric furnace, with a predetermined Fe-Ni composition (PD material: Fe-35.5 mass% Ni, PB material: Fe-46.5 mass% Ni, PC material: Fe-77.5 mass% Ni). Then, it moved to AOD or VOD, and oxidation refining was performed for processes, such as decarburization, dechromation, and dephosphorization. Dolomite was used for AOD and VOD refractories. After that, it is removed once, and flux such as limestone, fluorite, and silica sand is newly added to the AOD or VOD, and CaO-SiO ₂ -Al ₂ O ₃ -MgO-F slag is formed on the molten metal. did. Thereafter, deoxidation and desulfurization were performed using Al and / or Fe-Si alloy. In the case of the PC material, predetermined amounts of Mo and Cu were added thereafter. As the Mo source, metal Mo or Fe-Mo, and Cu used metal Cu. Some PC materials were also manufactured without Cu. After AOD or VOD, temperature adjustment and more precise component adjustment were performed with LF.

  Thereafter, the slab obtained by continuous casting was hot-rolled and cold-rolled to obtain a cold-rolled sheet having a thickness of 0.5 mm. This cold-rolled sheet having a thickness of 0.5 mm was subjected to magnetic annealing in a hydrogen atmosphere under conditions of 1100 ° C. soaking for 3 hours, and the magnetic properties were measured, and the following tests were performed.

[Analysis method of chemical components]
The chemical component was measured using a fluorescent X-ray apparatus. However, C and S were performed by a combustion weight method, and O was performed by an inert gas impulse melting infrared absorption method.

[Method of judging cracking during hot rolling]
As for the presence or absence of cracks during hot rolling, cracks exceeding 1 cm from the side edge of the sheet after hot rolling were considered to be cracked when 5 or more cracks per 1 m of the length of the hot rolled sheet were detected. When there are less than 5 locations per meter, there is no crack.

[Method of measuring the number and composition of inclusions]
The number of inclusions was 0.5 μm or more, and inclusions in the 1 mm × 1 mm area of the cross section of the hot-rolled plate were counted using a scanning electron microscope. The inclusion composition was quantitatively analyzed for O, Mg, Al, Si, Ca, and Mn using an energy dispersive X-ray spectrometer. The reason why the total in the table is less than 100 mass% is that trace amounts of other elements such as Fe and Cr were detected in some inclusions.

[Method for quantifying average composition of oxide inclusions]
The average composition of oxide inclusions is quantified by measuring 20 points using an energy dispersive X-ray spectrometer for inclusions of 5 μm or more.

[Measurement method of magnetic properties]
Based on JIS C2531, the direct current magnetization characteristics were obtained by measuring a φ45 mm × φ33 mm ring test piece with 50 turns on both the primary and secondary sides, and measuring the saturation magnetic flux density under a magnetic field of 1592 (A / m). The maximum relative permeability μm, initial relative permeability μi, and coercive force Hc are 4 (A / m) for the PC material, and 16 (A / m) for the PD and PB materials. It is measured as a magnetic field. A 0.5 mm cold-rolled plate was magnetically annealed in a hydrogen atmosphere at 1100 ° C. for 3 hours, and the magnetic properties were measured.

The test results are shown separately in Tables 1a to 1c (PC material), Tables 2a to 2c (PB material), and Tables 3a to 3c (PD material) together with the alloy composition and production conditions.
As shown in the table, Nos. 1 to 6, Nos. 11 to 16, and Nos. 21 to 26 of the invention examples have excellent magnetic workability while maintaining excellent hot workability. It was.

On the other hand, No.7, No.8, No.17, No.18, No.27, and No.28 of Comparative Examples all have [S] higher than the range of the present invention, and hot workability. However, the magnetic properties were not good. This is because the amount of solid solution [S] increases, the grain boundaries become brittle and the hot workability deteriorates, and the low melting point silicate mainly composed of SiO2 increases, and this silicate extends by hot rolling and cold rolling. This is considered to be a factor that hinders domain wall movement and further deteriorates magnetic properties.
In Comparative Examples No. 9, No. 19, and No. 29, Mg was higher than the range of the present invention, and all the magnetic properties were compatible with the present invention. The result was bad. This is presumably because low-melting intermetallic compound Ni ₂ Mg was formed. Moreover, Ca was also higher than the range of the present invention, and black spots were generated on the beads during welding. Furthermore, S was less than 0.0001 mass%, and the punching workability was also lowered.
The above examples are all examples of 60 tons, in which ingots, continuous casting, hot rolling, and cold rolling are performed using a refining equipment for stainless steel. Therefore, there is an effect that the manufacturing cost is significantly lower than the conventional vacuum melting of several tons.

The technology of the present invention controls the thermal expansion coefficient of shadow masks, bimetals, lead frames, and gun parts in addition to the manufacture of Fe-Ni magnetic alloy plates used for magnetic heads, magnetic shield materials, wound cores of transformer cores, etc. It can also be applied in the fields of materials, speedometer case materials, Curie point control materials such as electromagnetic cookers, and stainless steel.

Claims (6)

C: 0.001 to 0.2 mass%, Si: 0.01 to 0.5 mass%, Mn: 0.01 to 1.0 mass%, S: 0.0001 to 0.002 mass%, Ni: 30 to 85 mass%, Al: 0.001 to 0.1 mass%, Mg: 0.0002 ~ 0.05mass%, Ca: ≤0.0020mass% and O: 0.0002 ~ 0.01mass%, the alloy plate of the component composition consisting of the balance Fe and unavoidable impurities, the alloy plate also includes at least the above-mentioned Within the range of the component composition, the main component contains one or two of Al ₂ O ₃ and MgO containing 75 mass% or more of oxide inclusions composed of SiO ₂ ≦ 10 mass% and CaO ≦ 10 mass%. In addition, the vertical cross section parallel to the rolling direction includes oxide inclusions and / or sulfide inclusions having a size of 0.5 μm or more in a total amount of 50 to 300 pieces / mm ^2. Fe-Ni magnetic alloy plate with excellent hot workability. In addition to the above components, one or more selected from Mo, Cu, Co, and Nb are each contained in a range of 15 mass% or less and a total of 20 mass% or less. Item 2. An Fe—Ni-based magnetic alloy plate excellent in hot workability according to Item 1. An alloy plate containing 35 mass% or more and less than 40 mass% of Ni, exhibiting magnetic properties of maximum relative permeability μm: 50,000 or more, initial relative permeability μi: 10,000 or more, and coercive force Hc: 4 [A / m] or less The Fe-Ni-based magnetic alloy plate having excellent hot workability according to claim 1 or 2 . Alloy plate containing 40 mass% or more and 50 mass% or less of Ni, exhibiting magnetic properties of maximum relative permeability μm: 100,000 or more, initial relative permeability μi: 10,000 or more, and coercive force Hc: 4 [A / m] or less The Fe-Ni-based magnetic alloy plate having excellent hot workability according to claim 1 or 2 , wherein the Fe-Ni-based magnetic alloy plate is excellent. An alloy plate containing 70 to 85 mass% of Ni, which exhibits magnetic properties of maximum relative permeability μm: 200,000 or more, initial relative permeability μi: 100,000 or more, and coercive force Hc: 0.8 [A / m] or less. 3. The Fe—Ni based magnetic alloy plate having excellent hot workability according to claim 1 or 2 . A method for producing the Fe-Ni based magnetic alloy plate according to any one of claims 1 to 5 , wherein the molten Fe-Ni based alloy that has undergone primary refining is replaced with a lined refractory containing magnesia. After oxidative refining in the secondary refining vessel of either AOD or VOD, it is first removed, and then one or more fluxes of limestone, fluorite, and silica are added. , CaO-Al ₂ O ₃ -MgO-SiO ₂ -F-based slag is produced, and then Al and / or Si is introduced into the molten alloy, Al: 0.001 to 0.1 mass%, Si: 0.01 to 0.5 mass By deoxidizing and desulfurizing by preparing to% , O 2 : 0.0002 to 0.01 mass%, S: 0.0001 to 0.002 mass% of molten alloy is obtained, and then the molten alloy is continuously cast into a slab, A method for producing a Fe-Ni magnetic alloy plate excellent in hot workability, characterized by hot rolling after grinding.