JP6221406B2 - Fe-based metal plate and manufacturing method thereof - Google Patents

Description

  The present invention is an Fe-based metal plate having high strength and excellent magnetic properties suitable for parts to which large stress is applied, such as a rotor of a high-speed rotating machine, such as a magnetic core of a generator, an electric motor, or a transformer, and its manufacture It is about the method.

  Conventionally, silicon steel plates have been used for magnetic cores of electric motors, generators, transformers and the like. The silicon steel sheet is required to have a ratio B50 / Bs of the average magnetic flux density B50 to the saturation magnetic flux density Bs in a small excitation magnetic field and to have a low iron loss in an alternating excitation magnetic field. Furthermore, with recent miniaturization and higher power of motors, motors that rotate at high speeds at variable speed operation and commercial frequencies are increasing. Since the centrifugal force acting on such a rotating body increases in proportion to the square of the rotational speed, the material used for the rotor or the like needs to have high strength.

Regarding the Fe-based metal plate in which the {200} plane is highly integrated in the rolled surface and the ratio B50 / Bs of the average magnetic flux density B50 to the saturated magnetic flux density Bs is increased, the present inventors previously described The following technologies are proposed.
(A) attaching a ferrite-forming element to one side or both sides of a base metal plate made of an Fe-based metal in an α-γ transformation system;
(B) The base metal plate was heated from room temperature to A3 point of the base metal plate to diffuse the ferrite-forming elements in the base metal plate, and partly alloyed with the base material and alloyed A step of setting the {200} plane integration degree of the α-Fe phase in the region to 25% to 50% and the {222} plane integration degree to 40% or less;
(C) The base metal plate is heated and held at a temperature of A3 or higher to increase the {200} plane integration degree of the α-Fe phase alloyed with the ferrite-forming element, and { 222} reducing the degree of surface integration;
(D) When the base metal plate is cooled to a temperature below A3 and the γ-Fe phase in the non-alloyed region is transformed into the α-Fe phase, the degree of {200} plane integration of the α-Fe phase And having a {200} plane integration degree of 30% or more and 99% or less and a {222} plane integration degree of 30% or less. A method for producing an Fe-based metal plate having a degree of integration.

  In order to improve mechanical properties, solid solution strengthening and precipitation strengthening are generally used. However, since many of these strengthening methods deteriorate magnetic properties, it is very difficult to achieve both strength and magnetic properties. is there. On the other hand, in Patent Document 2, the Si amount is increased to 3.5 to 7.0%, and elements such as Ti, W, Mo, Mn, Ni, Co, and Al are added to use solid solution strengthening. The technology is described.

Further, Patent Document 3 proposes a high-strength electrical steel sheet in which an unrecrystallized structure remains in the steel sheet.
However, when the technique described in Patent Document 2 is applied to factory production, there is a problem that troubles such as plate breakage are likely to occur in a rolling process or the like. Further, Patent Document 3 has a problem that although the manufacturability is good, the variation in the strength of the steel sheet in the direction perpendicular to the rolling tends to increase.

International Publication No. 2011/052654 JP 60-238421 A JP-A-2005-113185

  The present invention has been made in view of such circumstances, and an object thereof is to provide an Fe-based metal plate having excellent magnetic properties and excellent mechanical properties, and a method for stably producing such a metal plate. .

  The present inventors diligently studied and examined the mechanical properties of Fe-based metal plates provided with various different elements. As a result, the present inventors have found that the Fe-based metal plate to which the heterogeneous element composed of the ferrite-forming element and the austenite-forming element is added is highly integrated at a low temperature, and at the same time, the crystal grains become fine due to the heat treatment at a low temperature. It has been found that mechanical properties are improved.

The Fe-based metal plate of the present invention is
(1) having an alloying region in which a heterogeneous element composed of a ferrite-forming element and an austenite-forming element is alloyed to form an α-Fe single phase on one side or both sides;
At least the thickness center part is an α-γ transformation component system,
{200} plane integration of the plate surface 99% or more and 30% or less, and {222} plane integration is Ri der than 30% 0.01%
When the concentration of the ferrite-forming element of the different element in the alloying region is x% and the concentration of the austenite-generating element is y% in mass%, 0.001 <y / x <5,
Ratio of average magnetic flux density B50 to saturation magnetic flux density Bs, B50 / Bs exceeds 0.85,
A Fe-based metal plate , wherein the plate thickness is 10 μm or more and 6 mm or less ,
Here, the {200} plane integration degree refers to 11 orientation planes ({110}, {200}, {211}, {310}, {222}, {321) of α-Fe crystals parallel to the sample surface. }, {411}, {420}, {332}, {521}, {442}), and dividing each of the measured values by the theoretical integrated intensity of the sample having a random orientation, { The ratio of 200} strength is obtained as a percentage.

(2) The austenite generating element of the alloyed different element is one or more of C, Co, Cu, Ni, N, Mn, and Pd, and the ferrite generating element is Al, Cr, Ga, Ge, Mo, Sb, The Fe-based metal plate according to (1), which is one or more of Si, Sn, Ta, Ti, V, W, and Zn.

( 3 ) A method for producing the Fe-based metal plate according to (1) or (2), wherein a different element is attached on a base metal plate made of Fe-based metal, and is diffused by heat treatment.
(A) a step of obtaining a base metal sheet by reducing the thickness from a cast slab made of Fe-based metal of α-γ transformation component by hot rolling and cold rolling with a rolling reduction of 97% or more and 99.99% or less; ,
(B) A heterogeneous element comprising a ferrite-forming element and an austenite-generating element is formed on one or both surfaces of the base metal plate, the thickness of the heterogeneous element layer is 0.05 μm or more and 1000 μm or less, and the outermost layer of the Fe-based metal plate is a process of adhering to form an α-Fe single phase;
(C) heating the base metal plate to which the different element is adhered to point A3 of the base metal plate, and diffusing the different element into the base metal plate;
(D) further heating and holding the metal plate at a temperature of A3 or higher and 1300 ° C. or lower to diffuse the different elements;
(E) A method for producing an Fe-based metal plate, comprising a step of cooling the metal plate to a temperature lower than A3.

According to the present invention, it was found that when a heterogeneous element composed of a ferrite-forming element and an austenite-forming element is diffused and heat-treated in an Fe-based metal plate, the texture can be controlled and higher mechanical properties can be obtained than before. .
In addition, according to the present invention, it is possible to stably produce an Fe-based metal plate having a controlled texture and compatible with high mechanical properties in a short time using existing equipment, and is excellent in economic efficiency. .

  As a result of further study of the method shown in Patent Document 1, the present inventors have added austenite-generating elements in addition to ferrite-forming elements as dissimilar elements to be diffused to the surface of the metal plate, thereby forming the texture of the metal plate. It was found that the mechanical properties were improved by controlling.

(Description of the basic principle of the present invention)
First, the basic principle that mechanical properties are improved over the prior art when different elements composed of ferrite-forming elements and austenite-forming elements are diffused will be described.

  In the present invention, an α-γ transformation composition is used for the Fe-based metal plate as a base material, and a heterogeneous element composed of a ferrite-forming element and an austenite-generating element is attached to one side or both sides thereof, and the foreign element is diffused An Fe-based metal plate having a controlled texture and excellent mechanical properties is obtained.

  The base metal plate is provided with a texture oriented in a direction close to {200} on one or both surfaces of the plate by strong processing, decarburization, or the like.

  In the step (a), the base metal plate is obtained by cold rolling the Fe-based metal of the α-γ transformation component at, for example, a reduction rate of 97% or more and 99.99% or less.

  In the step (b), a heterogeneous element composed of a ferrite-forming element and an austenite-forming element is attached to the base metal plate.

  In step (c), the metal plate to which the different elements are attached is heated to a point A3 or higher of the base metal plate, and part or all of the region in which the orientation close to {200} is oriented in the base metal plate Different elements are diffused and alloyed with the base material, and the α-Fe phase is stored in the alloyed region. Alternatively, the ferrite-forming element is diffused inside beyond the region where the orientation close to {200} is oriented to transform the region that was the γ-Fe phase into the α-Fe phase. At that time, since the transformation is carried out by taking over the preserved orientation of the α-Fe phase, a structure oriented in an orientation close to {200} is formed even in the alloyed region. Further, even in the α-phased grains, the orientation in the direction closer to {200} is further increased.

  In the step (d), the metal plate is heated and held at a temperature of A3 point or higher and 1300 ° C. or lower. Since the α-Fe single-phase component region does not cause γ transformation, crystal grains oriented in the direction close to {200} are stored as they are, and crystal grains in the direction close to {200} are preferentially grown in the region. Thus, the {200} plane integration degree is increased. Further, the region that is not the α-Fe single phase component is transformed into the γ-Fe phase. When the holding time is lengthened, the {200} crystal grains grow preferentially by biting, and as a result, the {200} plane integration degree is further increased.

  In the step (e), the metal plate is cooled to a temperature lower than A3 point. At this time, the γ-Fe phase in the non-alloyed inner region is transformed into the α-Fe phase. This internal region is adjacent to a region that is already α-Fe grains oriented in a direction close to {200} in the temperature range of point A3 or higher, and transforms from the γ-Fe phase to the α-Fe phase. At this time, the transformation takes over the crystal orientation of the adjacent α-Fe grains. For this reason, directions close to {200} are also accumulated in that region.

  When a ferrite-forming element and an austenite-generating element are applied as the different elements, the point A3 changes in the metal plate in the step (c). That is, the region where the dissimilar elements in the outermost layer are sufficiently alloyed becomes the α-Fe single phase, but the amount of alloy is small because the dissimilar elements diffused from the outermost layer are alloyed inside. For this reason, the influence of an austenite generating element appears greatly, and A3 point exists in this region. Therefore, the region transformed from the α-Fe phase to the γ-Fe phase in the step (d) can be widened and the orientation of this region can be made random, compared with the case where only the ferrite-forming element is diffused. . When cooled in the step (e), this region transforms from the γ-Fe phase to the α-Fe phase, but there are many γ grain boundaries that become nucleation sites of the α-Fe phase during the transformation. Later α-Fe grains become finer. Furthermore, the random grains of the γ-Fe phase in this region are transformed into the α-Fe phase by taking over the orientation of the {200} crystal grains preserved and grown in the α-Fe single phase region of the outermost layer. Oriented in near azimuth. Therefore, a metal plate having a high {200} plane integration degree and excellent mechanical properties can be obtained.

  Although the basic configuration of the present invention has been described above, the reasons for limiting the individual conditions that define the manufacturing method of the present invention and the preferable conditions for carrying out the present invention will be described.

(Components of base metal plate)
As the base metal plate, an Fe-based metal having an α-γ transformation component having an A3 point is used. C: Pure iron or low carbon steel composed of 1 ppm by mass to 0.2% by mass, the balance Fe and inevitable impurities, and appropriately containing additional elements. An α-γ transformation component silicon steel having C: 0.1% by mass or less and Si: 0.1-2.5% by mass may be used. By adding Mn and Cr, the α-γ transformation region can be expanded. Other impurities include trace amounts of Mn, Ni, Cr, Al, Mo, W, Ti, V, Nb, B, Cu, Co, Zr, Y, Hf, La, Ce, N, O, P, and S. Etc. are included.

(Types of ferrite-forming elements)
In particular, the ferrite forming element diffused from the surface layer of the base metal plate is preferably one or more of Al, Cr, Ga, Mo, Sb, Si, Sn, Ta, Ti, V, W, and Zn.

(Types of austenite-generating elements)
The austenite generating element diffused from the surface layer of the base metal plate is particularly preferably one or more of C, Co, Cu, Ni, N, Mn, and Pd.

(Fe metal plate thickness)
The thickness of the Fe-based metal plate is preferably 10 μm or more and 6 mm or less. When the thickness is less than 10 μm, the number of stacked layers increases and the number of gaps increases, and a high magnetic flux density cannot be obtained. Further, if the thickness exceeds 6 mm, the texture cannot be sufficiently controlled to the inside after cooling after the diffusion treatment.

(Texture of Fe-based metal plate)
The {200} plane integration degree of the α-Fe phase with respect to the plate surface of the product metal plate needs to be 30% or more and 99% or less. If the degree of integration is less than 30%, a sufficiently high magnetic flux density cannot be obtained. On the other hand, if it exceeds 99%, the magnetic flux density is saturated and the production becomes difficult. Desirably, it is 50% or more and 95% or less.
In addition, the measurement of the plane integration degree of the azimuth plane can be performed by X-ray diffraction using MoKα rays.

  More specifically, for each sample, there are 11 orientation planes ({110}, {200}, {211}, {310}, {222}, {321}, which are 11 α-Fe crystals parallel to the sample surface. {411}, {420}, {332}, {521}, {442}) are measured, and each measured value is divided by the theoretical integrated strength of a sample having a random orientation, and then {200} Determine the strength ratio as a percentage.

At that time, the {200} strength ratio is represented by the following formula (I).
{200} plane integration degree = [{i (200) / I (200)} / Σ {i (hkl) / I (hkl)}] × 100 (I)
However, the symbols are as follows.
i (hkl): Measured integrated intensity of {hkl} plane in the measured sample I (hkl): Theoretical integrated intensity of {hkl} plane in the sample with random orientation Σ: Sum of 11 orientation planes of α-Fe crystal Here, the integrated intensity of a sample having a random orientation may be obtained by preparing a sample and actually measuring it.

(Percentage of ferrite-forming elements and austenite-forming elements)
When the concentration of the ferrite-forming element of the heterogeneous element in the enriched region is x% in mass% and the concentration of the austenite-generating element is y% in mass% , adhesion is performed at a ratio satisfying 0.001 <y / x <5. . If y / x is less than 0.001, the A3 point of the diffusion region cannot be lowered sufficiently and the strength is not improved. On the other hand, if it exceeds 5, the γ-Fe phase remains after cooling, and the {200} plane integration degree decreases. More preferably, 0.005 ≦ y / x ≦ 4.

Next, a manufacturing method will be described. (Manufacturing method of base metal plate)
The base metal sheet is cold-rolled with an α-γ transformation component Fe-based metal at a reduction rate of 97% to 99.99%. When the rolling reduction is less than 97%, a high {200} plane integration degree cannot be obtained, and when it exceeds 99.99%, the increase of the {200} plane integration degree is saturated and the manufacturing cost increases. Instead of increasing the rolling reduction, a method of applying strain to the surface layer of the Fe-based metal plate such as blast or CCB may be used. Further, decarburization or de-Mn may be performed.

(Adhesion of different elements)
The thickness of the different element layer is preferably 0.05 μm or more and 1000 μm or less. If the thickness of the heterogeneous element layer is less than 0.05 μm, it may be difficult to sufficiently form an alloy region, and a sufficient α phase {200} plane integration degree may not be obtained. On the other hand, if the thickness of the different element layer exceeds 1000 μm, the different metal layer may remain thick after cooling to less than A3 point, and high magnetic characteristics may not be obtained. A different element may be attached by any one of EB vapor deposition, ion plating, plating, and sputtering. The ferrite-forming element and the austenite-generating element may be attached simultaneously by these methods, or may be attached separately.

(Diffusion heat treatment)
A base metal plate to which a heterogeneous element composed of a ferrite generating element and an austenite generating element is attached is heated to A3 point of the base metal plate to diffuse the dissimilar element partially or entirely in the base metal plate, Alloy the base material and store the alpha phase in the alloyed region. Then, the base metal plate is further heated to a temperature of A3 or higher and 1300 ° C. or lower and held. The already alloyed region has an α single-phase structure that does not undergo γ transformation, and the orientation of crystal grains in that region is preserved as it is. In addition, a region that is not α single phase causes γ transformation. Furthermore, with the diffusion of different elements, the γ-α transformation proceeds in the alloyed region. At that time, in the region adjacent to the region to be transformed, α grains in which the texture is already preserved are formed, and when transforming from the γ phase to the α phase, the transformation takes place in the form of taking over the crystal orientation of the adjacent α grains. On the other hand, as the holding time becomes longer, the texture becomes uniform, while the crystal grains become coarse and the strength is lowered. Therefore, the holding time is preferably 0.5 sec or more and 36000 sec or less.

  The invention is further described in the examples. The conditions in the examples are one example of conditions that were used to confirm the feasibility and effects of the present invention, and the present invention is not limited to these one example conditions. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
Ingots were cast by melting steels of steel types A to F shown in Table 1 in a vacuum melting furnace. The ingot was hot-rolled to a thickness of 45 mm in the γ region, and subsequently processed warm or cold to obtain a base metal plate. Table 1 shows the chemical composition and A3 point of the base metal plate. Next, the ferrite-forming element Al and the austenite-generating element Ni were adhered to both surfaces of the base metal plate so that the total thickness was 5 μm.

Next, heat treatment was performed on the metal plate to which the different elements were attached. An infrared furnace was used as the heat treatment furnace, and heat treatment was performed in an atmosphere evacuated to a level of 10 ⁻³ Pa. The holding time was 1200 sec at 1050 ° C.

Evaluation of the obtained Fe-type metal plate was performed as follows. First, the texture was evaluated by the X-ray diffraction method.
Subsequently, as for the tensile strength, a JIS No. 5 tensile test piece was sampled and the mechanical properties were measured. The ratio of the ferrite-forming element and the austenite-generating element was obtained from an average value obtained by measuring an area of φ100 μm at an arbitrary position on the surface of the metal plate by using an EPMA (Electron Probe Micro-Analysis) method. As for the magnetic characteristics, a magnetic flux density B50 with respect to a magnetizing force of 5000 A / m was obtained using an SST (Single Sheet Tester). At this time, the measurement frequency was 50 Hz. Next, the saturation magnetic flux density Bs was obtained using VSM (Vibrating Sample Magnetometer). At this time, the applied magnetizing force was 0.8 × 10 6 A / m. The iron loss was determined by a single plate magnetic tester (SST) in accordance with JIS C2256.

  As is clear from Tables 2 and 3, the base material component is an α-γ transformation component, and those having A3 point have a high {200} plane integration degree, and B50 / Bs is also 0.85. The tensile strength increased. On the other hand, in Comparative Example 1 where the base material was not an α-γ transformation component, B50 / Bs was significantly lower than 0.85, and the tensile strength was low.

(Example 2)
In this example, steel type A shown in Table 1 was used as a base material. This base material is obtained by melting an ingot by vacuum melting and then processing it into various thicknesses by hot rolling, warm or cold rolling. In hot rolling, an ingot having a thickness of 245 mm heated to 1200 ° C. was thinned to a thickness of 50 mm. Various plate materials were cut out from this hot-rolled plate by machining and rolled hot or cold to produce a base metal plate having a thickness of 0.1 to 5.6 mm. Various ferrite-forming elements and austenite-forming elements were adhered to both surfaces of the obtained base metal plate. Al, Mo, Si, Sn, and V were attached as ferrite forming elements, and Co, Cu, Ni, Mn, and Pd were attached as austenite generating elements. In the comparative example, the case where a ferrite-forming element or an austenite-forming element was attached alone, and a case where a different element was not attached was examined.

An infrared furnace was used as the heat treatment furnace, and heat treatment was performed in an atmosphere evacuated to a level of 10 ⁻³ Pa. The holding temperature was 900 ° C. to 1200 ° C., and the holding time was 5 to 18000 sec. Evaluation was performed by the same method as in Example 1.

  As is clear from Tables 4 and 5, it was found that all the inventive examples had a tensile strength of 350 MPa or more and at the same time B50 / Bs was 0.85 or more. On the other hand, when the conditions of the present invention were not met or when different elements were not attached, the texture could not be controlled and the tensile strength was low. Moreover, when y / x exceeded 5 like the comparative examples 2 and 3, B50 / Bs was low and the tensile strength was also low. Further, when only the ferrite-forming element was adhered as in Comparative Example 4, a high {200} plane integration degree was obtained, but the tensile strength was low. In Comparative Example 6, only the austenite-forming element was adhered, but in this case, the {200} plane integration degree was low and the tensile strength was low.

(Example 3)
In this example, steel type C shown in Table 1 was used as a base material. This base material is obtained by melting an ingot by vacuum melting and then processing it into various thicknesses by hot rolling, warm or cold rolling. In hot rolling, an ingot having a thickness of 245 mm heated to 1200 ° C. was thinned to a thickness of 50 mm. Various plate materials were cut out from this hot-rolled plate by machining and rolled hot or cold to produce a base metal plate having a thickness of 0.2 to 4.7 mm. Various ferrite-forming elements and austenite-forming elements were adhered to both surfaces of the obtained base metal plate. Cr, Ga, Sb, Ta, Ti, W, Zn were adhered as ferrite-generating elements, and Co, Cu, Ni, Mn, and Pd were adhered as austenite-generating elements. In the comparative example, the case where a ferrite-forming element or an austenite-forming element was attached alone was examined.

An infrared furnace was used as the heat treatment furnace, and heat treatment was performed in an atmosphere evacuated to a level of 10 ⁻³ Pa. The holding temperature was 960 ° C. to 1270 ° C., and the holding time was 0.5 to 6000 sec. Evaluation was performed by the same method as in Example 1.

  As is clear from Tables 6 and 7, all of the inventive examples have a tensile strength of 350 MPa or more and at the same time, B50 / Bs is 0.85 or more. On the other hand, when the conditions of the present invention were not met or when different elements were not attached, the texture could not be controlled and the tensile strength was low. Moreover, when y / x exceeded 5 like the comparative example 10, B50 / Bs was low and the tensile strength was also low. Further, when only the ferrite-forming element was adhered as in Comparative Example 11, a high {200} plane integration degree was obtained, but the tensile strength was low. In Comparative Example 12, only the austenite-forming element was adhered, but in this case, the {200} plane integration degree was low and the tensile strength was low.

（実施例４）
本実施例では母材に表１に記載の鋼種Ｄと鋼種Ｅを用いた。この母材は真空溶解によってインゴットを溶製した後に、熱間圧延、温間または冷間圧延により様々な厚みに加工したものである。熱間圧延は１２００℃に加熱した厚さ２２５ｍｍのインゴットを厚さ２５ｍｍまで薄肉化した。この熱間圧延板から機械加工によって各種の板材を切り出し、冷間で圧延を実施し、厚み０．００８〜６．２ｍｍの母材金属板を製造した。得られた母材金属板の両面にフェライト生成元素のＳｉやＺｎ、オーステナイト生成元素のＭｎ，Ｃｕを付着させた。熱処理は実施例２と同様に行った。保持温度は７００〜１３２５℃、保持時間を０．０５〜４００００ｓｅｃとした。評価は実施例１と同じ方法により行った。

Example 4
In this example, steel types D and E shown in Table 1 were used for the base material. This base material is obtained by melting an ingot by vacuum melting and then processing it into various thicknesses by hot rolling, warm or cold rolling. In the hot rolling, an ingot having a thickness of 225 mm heated to 1200 ° C. was thinned to a thickness of 25 mm. Various plate materials were cut out from this hot-rolled plate by machining and rolled in a cold manner to produce a base metal plate having a thickness of 0.008 to 6.2 mm. Ferrite-forming elements Si and Zn, and austenite-forming elements Mn and Cu were adhered to both surfaces of the obtained base metal plate. The heat treatment was performed in the same manner as in Example 2. The holding temperature was 700 to 1325 ° C., and the holding time was 0.05 to 40000 sec. Evaluation was performed by the same method as in Example 1.

  As is apparent from Tables 8 and 9, all of the inventive examples have a tensile strength of 400 MPa or more, and at the same time, B50 / Bs is 0.85 or more. On the other hand, when the conditions of the present invention were not satisfied, B50 / Bs was low and the tensile strength remained at a low level.

Claims (3)

It has an alloying region in which a heterogeneous element composed of a ferrite-forming element and an austenite-forming element is alloyed to form an α-Fe single phase on one side or both sides,
At least the thickness center part is an α-γ transformation component system,
{200} plane integration of the plate surface 99% or more and 30% or less, and {222} plane integration is Ri der than 30% 0.01%
When the concentration of the ferrite-forming element of the different element in the alloying region is x% and the concentration of the austenite-generating element is y% in mass%, 0.001 <y / x <5,
Ratio of average magnetic flux density B50 to saturation magnetic flux density Bs, B50 / Bs exceeds 0.85,
A Fe-based metal plate , wherein the plate thickness is 10 μm or more and 6 mm or less ,
Here, the {200} plane integration degree refers to 11 orientation planes ({110}, {200}, {211}, {310}, {222}, {321) of α-Fe crystals parallel to the sample surface. }, {411}, {420}, {332}, {521}, {442}), and dividing each of the measured values by the theoretical integrated intensity of the sample having a random orientation, { The ratio of 200} strength is obtained as a percentage.   The alloyed austenite generating element of different elements is one or more of C, Co, Cu, Ni, N, Mn, and Pd, and the ferrite generating elements are Al, Cr, Ga, Ge, Mo, Sb, Si, Sn 2. The Fe-based metal plate according to claim 1, wherein the Fe-based metal plate is at least one of Ta, Ti, V, W, and Zn. A method for producing an Fe-based metal plate according to claim 1 or 2, wherein a heterogeneous element is adhered on a base metal plate made of Fe-based metal, and is diffused by heat treatment.
(A) a step of obtaining a base metal sheet by reducing the thickness from a cast slab made of Fe-based metal of α-γ transformation component by hot rolling and cold rolling with a rolling reduction of 97% or more and 99.99% or less; ,
(B) A heterogeneous element comprising a ferrite-forming element and an austenite-generating element is formed on one or both surfaces of the base metal plate, the thickness of the heterogeneous element layer is 0.05 μm or more and 1000 μm or less, and the outermost layer of the Fe-based metal plate is a process of adhering to form an α-Fe single phase;
(C) heating the base metal plate to which the different element is adhered to point A3 of the base metal plate, and diffusing the different element into the base metal plate;
(D) further heating and holding the metal plate at a temperature of A3 or higher and 1300 ° C. or lower to diffuse the different elements;
(E) A method for producing an Fe-based metal plate, comprising a step of cooling the metal plate to a temperature lower than A3.