TW200932927A - Non-oriented electromagnetic steel plate having low high-frequency iron loss and process for producing the non-oriented electromagnetic steel plate - Google Patents

Abstract

Disclosed is a non-oriented electromagnetic steel plate having a low high-frequency iron loss. The non-oriented electromagnetic steel plate has an aluminum concentration gradient in the thickness-wise direction and is characterized in that the whole steel plate comprises, by mass, C: not more than 0.005%, Si: 2% to 4%, Mn: not more than 1%, and Al: 0.1% to 8% with the balance consisting of Fe and unavoidable impurities and the concentration of Al (% by mass) in the direction of the thickness of the plate satisfies the following formula (1). 0.1 < (Xs-Xc)/t < 100 (1) where Xs: concentration of Al at the surface of the steel plate, % by mass; Xc: concentration of Al at the center of the steel plate, % by mass; and t: depth from the surface of the steel plate at which the concentration of Al (% by mass) is Xc + 0.05(Xs - Xc), mm.

Description

200932927 VI. Description of the invention: [Ming ^ 々 mussels invention field

The present invention relates to a non-oriented electrical steel sheet using a high-frequency iron loss which is a material of a motor core (iron core). t Before the old "chair J invention background Ο In recent years, according to environmental protection or energy saving point of view, the interest in electric vehicles has increased, and the drive motor must be rotated and miniaturized at a high speed, while driving the 10 frequency system to form around 800 Hz. In the case of driving, since the high-frequency component of the driving frequency is overlapped with the driving frequency, the non-directional electromagnetic steel plate which is the core material of the motor must have excellent mechanical properties capable of high-speed rotation and miniaturization. At the same time, it has excellent magnetic properties in the high frequency field of 400Hz to 2kHz, 15 especially the iron loss characteristics. ^ Iron loss includes overcurrent loss and hysteresis loss, and the overcurrent loss is proportional to the square of the plate thickness, and The inherent resistance is inversely proportional. Therefore, in order to reduce the overcurrent loss, try to (1) thin the plate thickness from the beginning; and/or (ii) increase the amount of Si and/or A1 and increase the inherent resistance, and increase the strength of the steel plate (rotor 2〇) Rigidity. For example, Patent Document 1 discloses a non-directionality that defines the ratio of the amount of Si to the amount of A1 and the relationship between W1()/4(){) (W/kg) and the thickness (mm). Electromagnetic steel plate, Although the non-oriented electrical steel sheet of the literature 1 can reduce the iron loss near 400 Hz, the 'iron loss characteristic 3 200932927 in the frequency range of frequencies greater than 400 Hz is not necessarily good, and is to be driven at a frequency of 800 Hz or more or 800 Hz or higher. The motor core (core) material is not suitable. As mentioned above, in order to reduce the overcurrent loss, (1) thinning the plate thickness, and (ii) increasing the amount of Si and/or A1 is effective, however, Si in steel And / or 5 A1 increment will reduce the workability of the steel plate, and hinder the thinning of the steel plate. Therefore, if the Si and / or A1 in the steel is simply increased, it has been improved before and after 800 Hz or even greater than 1000 Hz. The material of the iron loss characteristic in the frequency field is not industrially stable. In order to develop a thin non-oriented electrical steel sheet having excellent iron loss characteristics in the frequency domain 10 of 800 Hz or even 1000 Hz, it is necessary to have a new one. The method disclosed in Patent Document 2 discloses a method of forming an A1 plating film or an Al-Mn alloy plating on one or both sides of a cold-rolled steel sheet by a melt plating method or a molten salt electrolytic plating method. The film is then subjected to alloying annealing to produce a non-oriented electrical steel sheet having excellent magnetic properties. The method of Patent Document 2 reduces iron loss to characteristics in the commercial frequency field (maximum 1.5T magnetization by 50 Hz alternating current) At the same time, the average energy loss of lkg) 'again, for this purpose, by the method of plating-alloying annealing', the A1 and / or Μ η which constitute the action of the 咼 咼 resistance, at least the coating of the 〇 film and the whole In the alloying, it is preferable to uniformly diffuse the crucible 1 to the entire steel sheet. However, it is not possible to reduce the iron loss in the high frequency field by this method. [Patent Document 1] Japanese Patent Laid-Open Publication No. 2-7 - 247 047 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 A non-oriented electrical steel sheet which can be used as a motor core (iron core) material driven in a high frequency region of 400 Hz to 2 kHz is provided. The inventors focused on the fact that in the high frequency region of 400 Hz to 2 kHz, the eddy current flows only to a depth of 5 〇 μηη from the surface of the steel sheet, and the method for increasing the resistance in the depth range of 50 μm from the surface of the steel sheet is forgotten. If the method of alloying the ore coating is performed after the plating of the Α1 coating having a thickness of several tens of μm is applied, the plating cost of the crucible 1 is increased, and if the crucible 1 is uniformly diffused to the entire steel sheet, Since the crucible 1 is also diffused to the surface layer portion where the eddy current does not flow when used at a high frequency, the diffusion to the center portion is in vain for high-frequency use. The inventors have found that high-frequency iron loss can be reduced if the plating resistance on the surface of the steel sheet is increased by a factor of ,1, and Α1 is diffused and diffused to an appropriate depth, and a gradient of Α1 concentration is formed on the surface of the steel sheet to a predetermined depth. The present invention has been completed based on the foregoing findings, and the gist thereof is as follows. (1) A non-oriented electrical steel sheet having a low-frequency iron loss has a concentration gradient of aluminum in the thickness direction, and the entire steel sheet contains, by mass%: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less and Α1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction satisfies the following formula (1). 〇.l&lt;(Xs-Xc)/t&lt;l〇〇 -(1) 5 200932927

Xs : A1 concentration (% by mass) of the surface of the steel sheet

Xc: A1 concentration (% by mass) in the center of the steel plate t: Al concentration (% by mass) is the distance from the surface of the steel plate to the Xc + 0.05 (Xs - Xc) (mm) (2) - Low-frequency high-frequency iron loss The grain-oriented electrical steel sheet has a concentration gradient of aluminum in the thickness direction, and the entire steel sheet contains, by mass%: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and A1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction satisfies the following formula (2). 0.1 &lt; (Xs'- Xc)/t&lt; 1〇〇 ...(2)

Xs' : maximum A1 concentration near the surface of the steel sheet (mass 〇/0)

Xc: A1 concentration (mass%) of the center of the steel plate t: Al concentration (% by mass) becomes Xc + 0.05 (XS - XC) The distance from the surface of the steel sheet (mm) 0) Low-frequency iron loss as in the above (1) The non-oriented electrical steel sheet, wherein the entire steel sheet is further selected from the group consisting of ρ: 〇·3% or less and s: 〇〇4〇/. Hereinafter, at least N: 0.02% or less, Cu: 5% or less, Nb: ι% or less, Ti · 1% or less, B: 0.01% or less, Ni: 5% or less, and Cr: 15% or less One type further contains at least one species selected from the group consisting of M〇, W, Sn, Sb, Mg, Ca, Ce, and Co in a total amount of 0.5% or less. (4) The non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (2), wherein the entire steel sheet is further selected from the group consisting of P: 0.3% or less, s: 〇〇 4% or less, and N: 0.02. % or less, Cu: 5% or less, Nb: 1% or less, 〇200932927 1% or less, B: 0.01% or less, Ni: 5% or less, and Cr: 15% or less, at least one of the group consisting of Further, at least J species selected from the group consisting of Mo, W, Sn, Sb, Mg, Ca, Ce, and Co are further contained in a total amount of 0.5% or less. 5

10 15

(5) The non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (1), wherein the thickness of the non-oriented electrical steel sheet is 0.1 mm to 〇3 mm. (6) The non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (2), wherein the thickness of the non-oriented electrical steel sheet is 0.1 mm to 0.3 mm. (7) The non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (1), wherein the non-oriented electrical steel sheet has an iron loss Wl () / a thickness of 4 〇 W / kg or less. (8) The non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (2), wherein the iron loss Wic/_ of the non-oriented electrical steel sheet is 4 〇W/kg or less. (9) A method for producing a non-oriented electrical steel sheet having low high-frequency iron loss, comprising the following procedure, that is, yw) annealing a hot-rolled steel sheet to obtain an annealing hot-rolled steel sheet, and the hot-rolled steel sheet contains % by mass :c: 〇〇〇5% or less, S!: 2% to 4%, Mn: 1% or less, A1: 〇1% to 4%, and more preferably selected from P: G.3% or less, S: 〇.〇4% or less, N: G burning below, Cu: 5% or less, Nb or less, Ti: 1% or less, B: 〇〇1% or less, Ni: 5% or less, and Cr: 15% or less At least in the group! And further comprising at least 0.5% of the total selected from the group consisting of 仏, w, %, %, ton, Ca, Ce, and Co, and (4) the remainder is &amp; (χ1) cold rolling of the annealed hot-rolled steel sheet and obtaining a cold-rolled steel sheet; (yl) the surface of the cold-rolled steel sheet is applied to the cold-rolled steel sheet and (10) Apply cold 7 200932927 Rolling steel sheet annealing process. 5 10 15 -... The method for producing a non-directional electromagnetic steel sheet having low damage includes the following procedure: (w) a procedure for annealing a hot milk steel sheet and obtaining an annealing hot-rolled steel sheet, and the hot-rolled steel sheet is % by mass Containing the following, si: 2% to 4%, Mn: 1% or less, A1: Q 1% Na, · more. It is selected from p: 〇.3% or less, s: reading % or less 'N: (four) 2% or less, Cu: 5% or less, Nb: 1% or less, Ti: 1% or less, B: below, NN 5% Below and Cr: at least 15% of the group consisting of! And more preferably 5% or less selected from the group consisting of Mo, W, Sn, Sb, Mg, Ca'Ce, and (10) and the remainder is &amp; (χ2) The procedure of applying the 镇1 敷 敷 得 得 热 热 热 ; ; ; ; ; ; 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火 退火The procedure of the steel plate, and the procedure for annealing the A1 plated cold-rolled steel sheet. (11) A method for producing a non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (9), wherein the A1 plating is performed by melt plating. (12) A method for producing a non-oriented electrical steel sheet having a low-frequency iron loss as described above (1), wherein the A1 plating is performed by melt plating. (13) A method of producing a non-oriented electrical steel sheet having a low-frequency iron loss as described in (9) above, wherein the A1 plating is performed by vapor deposition. (14) A method for producing a non-oriented electrical steel sheet having a low-frequency iron loss as described above (1), wherein the A1 plating is performed by vapor deposition. (15) The method for producing a non-oriented electrical steel sheet having a low-frequency iron loss as described in the above (9), wherein the annealing is performed at 100 (TC or less for 1 hr or more. 20 200932927 (16) The high frequency as described in (10) above A method for producing a non-oriented electrical steel sheet having low iron loss, wherein the annealing is performed at 1000 ° C or lower for 1 hr or longer. 5 ❹ 10

15 G 20 (17) The method for producing a non-oriented electrical steel sheet having a low frequency iron phase as described in the above (9), wherein the non-oriented electrical steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction. Further, the entire steel sheet contains, by mass%: C: 0.005% or less, Si: 2% to 4%, Μη. 1% or less, and A1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities. Further, the A1 concentration (% by mass) in the thickness direction satisfies the following formula (3). 0.1&lt;(Xs-Xc)/t&lt; 100 ...(3)

Xs : A1 concentration (% by mass) of the surface of the steel sheet

Xc : A1 concentration (mass %) of the center of the steel plate t: A1 concentration (% by mass) becomes Xc + 0.05 (Xs - Xc) The distance from the surface of the steel plate (mm) (18) The high-frequency iron loss as described in (9) above A method for producing a non-oriented electrical steel sheet, wherein the non-oriented electrical steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction, and the entire steel sheet contains, by mass%: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and A1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction satisfies the following Formula (4). 0.1&lt;(Xs, a Xc)/t&lt; 100 ---(4)

Xs' · The maximum A1 concentration near the surface of the steel sheet (% by mass)

Xc : A1 concentration (mass%) of the center of the steel plate 1: 8% concentration (% by mass) becomes 〇 + 0.05 (also 8 - (:) the distance from the surface of the steel plate (mm) 9 200932927 (19) as mentioned above ( (10) A method for producing a non-oriented electrical steel sheet having a low-frequency iron loss, wherein the non-oriented electrical steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction, and the entire steel sheet contains a mass%: C : 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and A1: 0.1% 5 to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration in the thickness direction (% by mass) satisfies the following formula (5): 0.1 &lt; (Xs - Xc) / t &lt; 100 ... (5)

Xs : A1 concentration (% by mass) of the surface of the steel sheet

Xc: A1 concentration (mass%) of the center of the steel plate 10 t: Al concentration (% by mass) becomes Xc + 0.05 (Xs - Xc) The distance from the surface of the steel sheet (mm) (20) The high-frequency iron as described in (10) above A method for producing a non-oriented electrical steel sheet having a low loss, wherein the non-oriented electrical steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction, and the entire steel sheet contains, by mass%: 15 C : 0.005% or less. Si: 2% to 4%, Μη: 1% or less, and A1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction is satisfied. The following formula (6). 0.1&lt;(Xs'-Xc)/t&lt; 100 ...(6)

Xs': maximum A1 concentration (% by mass) near the surface of the steel sheet 20 Xc: A1 concentration (% by mass) at the center of the steel plate t: Al concentration (% by mass) becomes the depth of the surface of the steel sheet from Xc + 0.05 (Xs-Xc) ( Mm) Brief Description of the Drawings Figure 1A shows the A1 concentration profile of the plate 10 200932927 thick direction after A1 plating and annealing at 900 °C for 1 hr. Fig. 1B is a graph showing the A1 concentration distribution in the thickness direction of A1 plating after annealing at 900 °C for 1 hr. Fig. 2 is a graph showing the relationship between the film thickness of the plating 5 and the magnetic flux density B3 (T) after annealing after annealing at 900 °C for 1 hr and 10 hr after A1 plating. Fig. 3 is a graph showing the relationship between the film thickness of the plating and the iron loss W1 () / 4 (H) (W / kg) after annealing at 900 ° C for 1 hr and 10 hr after A1 plating. Fig. 4 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/8()0 (W/kg) after annealing at 900 °C for 1 hr and 10 hr after A1 plating. 10 Fig. 5 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/1200 (W/kg) after annealing at 900 °C for 1 hr and 1 hr after A1 plating. Fig. 6 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/170 () (W/kg) after annealing at 900 ° C for 1 hr and 1 hr after A1 plating.

I: Embodiment: J 15 The best form for carrying out the invention The non-oriented electrical steel sheet of the present invention (the steel sheet of the present invention) contains, by mass, :/〇: c: 0.005% or less, Si: 2% to 4%, Μη : 1% or less and A1 : 0.1% to 4%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction satisfies the following formula (丨) or 20 (2). (1) (2) 0.1 &lt; (Xs - Xc) / t &lt; 100 0.1 &lt; (Xs' - Xc) / t &lt; 100 Xs : A1 concentration (% by mass) of the surface of the steel sheet

Xs' : maximum A1 concentration (% by mass) near the surface of the steel sheet 11 200932927

Xc: A1 concentration (mass%) of the center of the steel plate t: A1 concentration (% by mass) becomes the distance (X) of Xc + 〇.〇5 (Xs-Xc) from the surface of the steel sheet. First, the composition of the steel sheet of the present invention is specified. The reason, in addition, 5% refers to the mass%. Since the C system is an element which deteriorates the iron loss after strain relief annealing, it is set to 0.005% or less in order to prevent the effect from occurring. Since the Si system is an element effective for increasing the electric resistance and reducing the iron loss, it is added in an amount of 2% or more. However, if it is excessively added, the cold calendering property is remarkably deteriorated by 10, so it is set to 4% or less. Like Si, Μη is used to increase the effective element of resistance. However, if it is added more than 1%, it will hinder the grain growth during annealing. Therefore, it is set to 1〇/0 or less 'again' because Μη can be used in steel. S is harmless (MnS), so it is preferable to add 0.1% or more. 15 Like Si, since A1 is an element effective for increasing electric resistance and reducing iron loss, it is added in an amount of 0.1% or more, and more preferably 0.5% or more. However, if it is excessively added, the castability of steel deteriorates, and the A1 system of the mother steel sheet (the steel sheet before the A1 plating) is set to 4% or less. A1 increases the amount of 2〇A1 in the steel by chain-annealing from the surface into the steel. However, in the part where A1 is excessively increased, the saturation magnetic flux density is low and the magnetic properties of the steel are deteriorated. AH is the upper limit of the total thickness of the total thickness in the plate after annealing. P is an element which is excellent in the effect of resisting tension. However, it is not necessary to add it to the steel sheet of the present invention. If it is more than 0.3%, the embrittlement is intense, and the hot rolling 'cold rolling treatment on the industrial scale 12 200932927 becomes difficult. Therefore, the content of &gt; is preferably set to 0.3% or less, and more preferably 0.2% or less, and more preferably 〇 15% or less. The content of S is preferably as low as possible and is preferably 〇〇4% or less, and more preferably 0.02°/° or less, more preferably 0.01% or less. Since the Cu system has an effect of increasing the strength in a range that does not adversely affect the magnetic properties, it may contain Cu and has an upper limit of 5%.

Nb is not only intrinsic Nb, but also Nb mainly forms carbonitrides in steel sheets, and is used to retard the recrystallization of steel sheets, and also by fine 10 Nb precipitates, because it does not have magnetic properties. The range that causes adverse effects increases the intensity, so it can also contain 1% or less. Similarly to c, since the magnetic properties are deteriorated, it is preferably set to 〇〇2% or less. In addition, most of the elements used in the high-strength electromagnetic steel sheets of the prior art are not only the cost of addition but are also considered to be problems, and since there are many adverse effects on the magnetic properties, it is not necessary to add them. When it is intentionally added, Ti, B, and/or ^ are added according to the recrystallization retardation effect, the high-strengthening effect, the cost increase, and the magnetic property deterioration. In this case, the addition is preferably Ti: 1%. Below, B: 0.01% or less, see: 5. /0 is 20 Cr : 15% or less. Further, other trace elements are not affected by the inevitable content of ore or crumb, and even if added for various known purposes, the effects of the present invention are not impaired. Further, it also includes an element which forms at least a precipitate of fine carbides, sulfide nitrides, and/or oxides and exhibits a substantial amount of crystal retardation effect of the re-supplied 13 200932927, and the adverse effects of the fine precipitates on the magnetic properties Also, since the steel sheet of the present invention can obtain a sufficient recrystallization retardation effect by CU or Nb, it is not necessary to add these elements. The inevitable content of these trace elements is usually 〇005〇/. In the following, however, it may be contained in an amount of 0.01% or more for various purposes. In this case, the contents of Mo, W, Sn, Sb, Mg, Ca, Ce, and Co are preferably set to be total according to the combination of cost and magnetic properties. 0.5% or less. In the present invention, the surface of the mother steel sheet of the above composition is subjected to ... mineralization' and then annealed and A1 is diffused into the steel. The A1 plated mother steel plate has been subjected to annealed hot-rolled steel sheets (annealed hot-rolled steel sheets) or cold-rolled steel sheets which have been cold-rolled annealed hot-rolled steel sheets. Annealing has been cold-rolled to the surface of the cold-rolled steel sheet with a thickness of ασ, and then the annealing is performed. However, when the surface of the annealed hot-rolled steel sheet is plated, it is subjected to cold rolling to the thickness of the product. annealing. 15 20 The thickness of the mother steel plate is not particularly limited. It can be considered as the lower limit of the thickness of the steel plate in the final product (4). The thickness of the steel plate for the final product is not limited. However, if it is high From the viewpoint of the reduction of the frequency iron loss, it is preferably from 0.1 mm to 〇.3 mm. If you consider the materials used in the high-frequency field to drive the motor and other points of view, the newcomer _ 骑 敷 之 之 来自 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = It is also possible to wait for vapor phase plating. ·,,, and right, however, due to the cold rolling in the annealing heat will

The thickness of A1 plating is not particularly limited. When the steel plate is bonded with A, the thickness of the plate is 14 until the thickness of the plate is 14 200932927. The thickness of the plating is reduced to 1/5, so it is suitable to be plated with the thickness reduction. The thickness of the coating, for example, δ, is intended to be 0.1 to 30 mm when the thickness of the product is O. linm to 〇 3 mm, and the thickness of the annealed hot-rolled steel sheet is preferably 30 μm. 5 After the 钢板1 bond is applied to the mother steel sheet, annealing is performed and Α1 is diffused into the steel, and a Α1 concentration gradient satisfying the above formula (1) or (2) is formed (this point is as will be described later). The annealing condition (temperature, time) is not particularly limited as long as it can form the concentration gradient of the gossip. However, if batch annealing is used, it is preferably "1". Further, the annealing condition may be set under the condition that the continuous annealing is 1 。. Next, the steel sheet of the present invention is characterized in that the concentration after plating-annealing satisfies the above formula (1) or formula (2). The figure shows that the thickness of the cold-rolled steel sheet (mother steel plate) of 0.3 mm thick is Ιμιη (Y in the first figure), 3μηη (X in the first figure), and ι〇μπι (15 W in the first figure). The A1 plating film 'then annealing is formed in the thickness direction of the Α1 concentration distribution'. The cold-rolled steel sheet contains: C: 〇.〇〇3%, Si: 3.1%, Mn: 0.3%, A1: 1.1%' The remainder is composed of inevitable impurities. Figure 1A shows 900. (: When annealing for 1 hr, the ιΒ diagram shows annealing at 10 〇〇 20 °c for 10 pm. Also, in Figure 1 In the comparison, the A1 concentration distribution at the time of annealing without performing A1 plating (Z in Fig. 1) is also shown. It can be seen from the 1A and 1B drawings that the sheet thickness is The A1 concentration (% by mass) in the direction is such that the A1 concentration (mass °/〇) from the surface or the maximum A1 concentration (% by mass) near the surface is substantially linearly eliminated toward the center portion of the steel sheet. 15 200932927 The inventor has a plate The iron loss characteristic and the magnetic flux density of the steel sheet having the A1 concentration (% by mass) in the thick direction and the steel sheet after the annealing without A1 plating, and the annealing also constitute the function of recrystallizing the steel sheet. Therefore, in order to confirm the gradient according to the A1 concentration Whether or not there is a difference in magnetic properties, the steel sheet without A1 ore is also annealed by the same annealing conditions. Fig. 2 shows the film thickness of the plating after annealing at 9 ° C for 1 hr and 10 hr after A1 plating. The relationship between the magnetic flux density B3 (T) after annealing and the average of B3 (T) measured in the L direction (rolling direction) and the C direction (perpendicular to the rolling direction) (2nd) In the figure, B3(T)(L+C) is used to indicate the vertical axis. The magnetic flux density is 10 degrees Β3 (τ), which tends to decrease due to annealing. However, by appropriately selecting A1 plating thickness and annealing time It can ensure more than 1.2T. Figure 3 shows the annealing at 900 °C for 1hr and 10hr after A1 plating. The relationship between the film thickness of the plating and the iron loss W1()/4(9) (W/kg), and the third figure shows the measurement in the L direction (rolling direction) and the C direction (perpendicular to the rolling direction) 15 (W) /kg) The average value (in the third figure, W丨〇/400 (W/kg) (L+c) indicates the vertical axis). By appropriately selecting the A1 plating thickness and annealing time, w1Q/ can be reduced. 40() (W/kg). 〇 Figures 4 to 6 show the film thickness of the plating and the iron loss W1Q/_ in the high frequency field after annealing at 900 °C for 1 hr and 10 hr after A1 bonding. /kg), 20 iron loss Wio/1200 (W/kg) and iron loss Wi〇/17〇〇 (W/kg) relationship, but 'iron loss W丨〇/80〇 (W/kg) (L+ c) is the average value of ^/na (W/kg) in the L direction (rolling direction) and the c direction (perpendicular to the rolling direction), and the iron loss Wi〇/i2〇〇(W/kg) (L + c) The average value of 1()/12(){) (W/kg) in the L direction (rolling direction) and the C direction (perpendicular to the rolling direction), and further, the iron loss w1Q/1700 16 200932927 (W /kg) (L+c) is the average value of W1G/丨7G() (W/kg) in the L direction (rolling direction) and the C direction (perpendicular to the rolling direction). 5 ❹ 10 15 ❹ 20 As can be seen from Figures 4 to 6, the high-frequency iron loss characteristics can be improved by annealing at 900 ° C for 10 hours after the A1 is applied, compared to the annealed steel sheet without A1 plating. Accordingly, as shown in Fig. 1, it is generally considered that the reason for the increase in the iron loss characteristic in the high-frequency field is that the concentration of Α1 in the depth region of 5 〇 μη from the surface of the steel sheet is diffused by Α1 by annealing. Rise and increase due to the iron loss characteristics in the field. The inventors further investigated the correlation between the concentration of Α1 (% by mass) after annealing and the high-frequency iron loss. As a result, it has been found that in order to reduce the high-frequency iron loss, the Α1 concentration (% by mass) in the thickness direction must satisfy the following formula (1). 0.1&lt;(Xs-Xc)/t&lt; 100 -.(1)

Xs : A1 concentration (% by mass) of the surface of the steel sheet

Xc: A1 concentration (mass%) at the center of the steel plate t: A1 concentration (% by mass) is the distance from the surface of the steel sheet (mm) to Xc + 0.05 (Xs - Xc). If the value of (Xs-Xc)/t is 0_1 or less , A1 will uniformly diffuse and distribute to the entire field of the steel sheet, and the iron loss in the surface layer of the steel sheet is not lowered, so the value of (Xs - Xc) / t is set to be greater than 0.1, and it is desirable that More than 0.5, more desirably greater than 5, especially greater than 20. If the value of (Xs - Xc) / t is 100 or more, the gradient of the concentration of A1 becomes steep in the narrow range, and the rising characteristic at the time of excitation is remarkably deteriorated, 17 200932927 Therefore (Xs - Xc) / t The value is set to be less than 丨〇〇, and more desirably less than 60, and more desirably less than 4 〇. Further, the depth t is not particularly limited as long as it is a surface portion including a vortex current in which high frequency induction occurs (a depth region of 5 〇 μη from the surface). In the above formula (1), the A1 concentration (Xs) of the surface of the steel sheet is used. However, since the maximum A1 concentration (Xs') near the surface of the steel sheet is actually used when the A1 concentration distribution is actually calculated, it is also possible to replace the above formula (1). The following formula (2) is used. In this case, the vicinity of the surface of the steel sheet means the following range, that is, in the electromagnetic steel sheet, the uppermost layer of the base iron under the insulating coating and the magnesite coating is used as a starting point. 'And the distance from the center of the steel plate is 5 μιηη as the end point. 〇.l&lt;(Xs’-Xc)/t&lt; 100 -..(2)

Xs': the maximum A1 concentration (mass 0/〇) in the vicinity of the surface of the steel sheet. In the present invention, the above formulas (1) and (2) can be used as needed. 15 (First Embodiment) Next, a first embodiment of the present invention will be described. However, the conditions of the first embodiment are used to confirm the feasibility and effect of the present invention. In the case of the present invention, various conditions can be employed as long as the object of the present invention is achieved without departing from the gist of the present invention. 20 in the mass%%: C: 0.003%, Si: 3.1%, Μη: 0.3%, Α1. 1.1% and the remaining part is composed of ^ and unavoidable impurities on the 2. 〇 mm thick hot-rolled steel sheet After annealing for 1 minute at l〇〇〇°c, cold rolling is performed to 0.3 mm thick, and (a) intact; (b) 1.5 μm thick A1 vapor deposition on both sides of the steel plate (c) Applying A32 vapor deposition of 200932927 4μιη thick on both sides of the steel plate; (d) performing 8μιη thick steamer on both sides of the steel plate ·' and (e) applying Ai 30μιη thick on both sides of the steel plate Evaporator. Next, annealing was performed at 900 ° C for 6 hours, and by this annealing, A1 was diffused into the steel while the steel sheet was recrystallized. The magnetic properties were measured by a single-plate magnetic measuring device, and the A1 concentration in the thickness direction was measured by EpMA line analysis of the steel plate cross section orthogonal to the rolling direction (L direction). [Table 1] Sample No. Surface A1 Concentration Xs (%) 亘 亘 = 乂 (: + 〇. 〇 5 (Xs - Xc) The distance from the surface of the steel plate t (171 is called A1 concentration gradient (Xs-Xc) / t Iron loss Wi〇/8〇〇(W/kg) Remarks (a) u — 0 40.5 -~~~~. Comparative example (b) 1.5 0.07 5.7 39.7 ---- Invention example (c) 2.8 0.08 21.3 38.3 Invention Example (d) 3.4 0.09 25.6 36.4 Inventive Example (e) 11.2 0.09 ------ 112.2 41.1 Comparative Example © 10 As can be seen from Table 1, if the A1 concentration is within the range of the concentration gradient specified in the present invention (the above formula ( 1) or (2)), the high-frequency iron loss is small. Industrial Applicability By the present invention, a non-oriented electrical steel sheet can be provided, and the non-oriented electrical steel sheet is excellent in use as The high-frequency iron loss of the motor core (core) material driven in the south frequency domain of 400 Hz to 15 2 kHZ is extremely steep and has appropriate magnetic characteristics as the core of the motor or transformer. Therefore, the present invention will be non-directional. The use of electromagnetic steel sheets as a material in the electrical appliance manufacturing industry is highly available. 19 200932927 L-mode simple description j Figure 1A shows annealing at 900 ° C for 1 hr A1 concentration distribution in the thickness direction of A1 plating-annealing" Fig. 1B shows the A1 concentration distribution in the direction of the 5th plate thickness after annealing and annealing at 900 °C for 1 hr. The relationship between the film thickness of the plating at 900 ° C for 1 hr and 10 hr after plating at A1 and the magnetic flux density B3 (T) after annealing is shown.

Fig. 3 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/4()() (W/kg) after annealing at 900 °C for 1 hr and 10 hr after A1 plating. 10 Fig. 4 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/_(W/kg) after annealing at 900 °C for 1 hr and 10 hr after A1 plating. Fig. 5 is a graph showing the relationship between the film thickness of the plating and the iron loss W10/12()() (W/kg) after annealing at 900 °C for 1 hr and 10 hr after A1 plating. Fig. 6 is a graph showing the relationship between the film thickness of the plating 15 and the iron loss W10/17()0 (W/kg) after annealing at 900 °C for 1 hr and 10 hr after A1 plating. [Main component symbol description] 〇 (none) 20

Claims (1)

200932927 VII. Patent application scope: . ι_ A non-oriented electromagnetic steel plate with low high-frequency iron loss, which has a concentration gradient of aluminum in the thickness direction, and the whole steel plate contains mass%: c: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and A1: 0.1% 5 to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction is satisfied. (1), namely: 0.1 &lt; (Xs - Xc) / t &lt; 100 (1) Xs : A1 concentration (% by mass) of the surface of the steel sheet ❹ Xc : A1 concentration (% by mass) of the center of the steel sheet 10 t: The A1 concentration (% by mass) is the depth (mm) of the surface of the steel sheet from Xc + 0.05 (Xs - Xc). 2. A non-oriented electromagnetic steel sheet with low high-frequency iron loss, which has a concentration gradient of aluminum in the thickness direction, and the entire steel sheet contains: C: 0_005% or less, Si: 2% to 4%. Μη : 1% or less and A1 : 0.1% 15 to 8%, and the remainder is composed of Fe and unavoidable impurities, and the A1 concentration (% by mass) in the thickness direction satisfies the following formula (2) , ie: ❾ 0.1 &lt; (Xs, a Xc) / t &lt; 100 -- (2) Xs ' : the maximum A1 concentration near the surface of the steel sheet (% by mass) Xc : A1 concentration (mass %) at the center of the steel sheet 20 t : The A1 concentration (% by mass) becomes the depth (mm) of the surface of the steel sheet from Xc + 0.05 (Xs - Xc). 3. A non-oriented electrical steel sheet having a low-frequency iron loss as in the first paragraph of the patent application, wherein the entire steel sheet is further selected from the group consisting of P: 0.3% or less, S: 0.04% or less, and N: 0.02%. In the following, at least one of a group consisting of Cu: 5% or less, Nb: 21 200932927 1% or less, Ti: 1% or less, B: 0.01% or less, Ni: 5% or less, and Cr: 15% or less, and Further, at least one selected from the group consisting of Mo, W, Sn, Sb, Mg, Ca, Ce, and Co is contained in an amount of 0.5% or less in total. 5 4. The non-oriented electrical steel sheet having a low-frequency iron loss as in the second paragraph of the patent application, wherein the entire steel sheet is further selected from the group consisting of P··0.3% or less, S··0.04% or less, and N. : at least one of 0.02% or less, Cu: 5% or less, Nb: 1% or less, Ti: 1% or less, B: 0.01% or less, Ni: 5% or less, and Cr: 15% or less. Further, at least one selected from the group consisting of Mo, W, Sn, Sb, Mg, Ca, Ce, and Co is contained in a total of 10 or less. 5. The non-oriented electromagnetic steel sheet having low high-frequency iron loss according to the first aspect of the patent application, wherein the thickness of the non-oriented electrical steel sheet is 0.1 mm to 0.3 mm. 15 6. The non-oriented electrical steel sheet having low high-frequency iron loss according to item 2 of the patent application scope, wherein the thickness of the non-oriented electrical steel sheet is 0.1 mm to 0.3 mm 〇 7. as claimed in claim 1 A non-oriented electrical steel sheet having a low frequency iron loss, wherein the iron loss of the aforementioned non-oriented electrical steel sheet is W! 〇/8 〇〇 40 W/20 kg or less. 8. A non-oriented electromagnetic steel plate having a low-frequency iron loss as in the second aspect of the patent application, wherein the iron loss of the non-oriented electrical steel sheet is less than or equal to 40 W/kg. 9. A method for manufacturing a non-oriented electrical steel sheet having low high-frequency iron loss, comprising 22 200932927 15 20 There are the following procedures: (W) A procedure for annealing a hot-rolled steel sheet to obtain an annealed hot-rolled steel sheet, and the hot-rolled steel sheet contains: C: 〇·〇〇5% or less, si. 2% to 4 %, Μη : 1% or less, A1 : 〇, 1% to 4%, and more selected from Ρ : 0.3% or less, S : 0.04% or less, Ν : 〇〇 2% or less, &amp; : 5% or less , Nb : P / ο or less, Ti : 1% or less, B : 〇〇 1% or less, Ni: 5% or less, and Cr: 15% or less, at least one of the group consisting of, and a total of 0.5% The following is selected from the group consisting of M〇, w, %, sb, Mg, Ca, Ce, and Co, and the remainder is composed of Fe and unavoidable impurities; (xl) cold rolling The procedure of annealing the hot-rolled steel sheet to obtain a cold-rolled steel sheet; (yl) a procedure of applying A1 ore on the surface of the cold-rolled steel sheet and obtaining a cold-rolled steel sheet of Jingfu; and Λ (Ζ), then depositing the aforementioned Α1 ore The procedure for annealing steel sheets. The method for manufacturing a non-oriented electrical steel sheet having a low melon-species-frequency iron loss includes the following procedure: 3 (W) a process of firing hot-rolled steel (four) and obtaining annealed hot-rolled steel &amp; The mass% contains: C: 〇〇〇 5% or less, Si · 2% to 4%, Mn: 1% or less, A1: 〇 1% to 4%, and more preferably selected from P: 0_3% or less, S: 0.04% or less, N: 0.02% or less, c · catching the following, Nb: 1% or less, τ γ: 1% or less, B: 0.01% or less, Νι · 5% or less, and Cr: 15% or less 】 species, and more in total, 〇·5% or less selected from 乂. , w, 、, %, 23 200932927 At least one of the group consisting of Mg, Ca, Ce and Co, and the remainder consisting of Fe and unavoidable impurities; (x2) in the annealed hot-rolled steel sheet Procedure for obtaining a surface by weaving and obtaining a hot-rolled steel sheet of A1 ore; 5 (y2) cold rolling the A1 plated hot-rolled steel sheet and obtaining a procedure of A1 plating cold-rolled steel sheet; and (z) then 'the aforementioned A1 mineral deposit The procedure for annealing cold rolled steel sheets. 11. The method for producing a non-oriented electromagnetic steel sheet having a low-frequency iron loss according to the ninth aspect of the patent application, wherein the A1 plating is applied by melt plating for 10 rows. 12. The method of producing a non-oriented electromagnetic steel sheet having a low high-frequency iron loss according to the first aspect of the patent application, wherein the A1 plating is performed by melt plating. 13. The method for producing a non-oriented electromagnetic steel 15 sheet having a low high-frequency iron loss according to the ninth application of the patent application, wherein the A1 plating is performed by vapor deposition. 14. The method for producing a non-oriented electromagnetic iridium steel sheet having a low-frequency iron loss according to the first aspect of the patent application, wherein the A1 plating is performed by vapor deposition. 15. The method for producing a non-oriented electromagnetic steel sheet having a low high-frequency iron loss according to the ninth aspect of the patent application, wherein the annealing is performed at a temperature of 1 〇〇〇 1 or less for 1 hr or more. 16. The method for producing a non-oriented electromagnetic steel sheet having a low high-frequency iron loss according to the first aspect of the patent application, wherein the annealing is performed for less than 1 hr below the lootrc. 17_The non-directional electromagnetic steel having low low-frequency iron loss according to the ninth application patent scope 200932927 5 The manufacturing method of the board, wherein the non-directional electromagnetic steel sheet having low high-frequency iron loss has a concentration of aluminum in the thickness direction Gradient, and the whole steel plate contains: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and Α1: 0.1% to 8%, and the remainder is made of Fe and impurities which are not avoided. Further, the A1 concentration (% by mass) in the thickness direction satisfies the following formula (3), that is, 0.1 &lt; (Xs - Xc) / t &lt; 100 - * (3) ❹ 10 Xs : surface of the steel sheet A1 concentration (% by mass) Xc: A1 concentration (mass%) at the center of the steel plate t: The A1 concentration (% by mass) is the depth (mm) of the surface of the steel sheet from Xc + 0.05 (Xs - Xc). 15 ❹ 18. The method for producing a non-oriented electrical steel sheet having low high-frequency iron loss according to the ninth application of the patent application, wherein the non-oriented electromagnetic steel sheet having low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction, Further, the entire steel sheet contains, by mass%: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and Α1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities. Further, the A1 concentration (% by mass) in the thickness direction satisfies the following formula (4), that is, 0.1 &lt; (Xs, -Xc) / t &lt; 100 - (4) 20 Xs' : the maximum near the surface of the steel sheet A1 concentration (% by mass) Xc: A1 concentration (mass%) at the center of the steel plate t: The A1 concentration (% by mass) is the depth (mm) of the surface of the steel sheet from Xc + o.05 (Xs - xc). 19. The invention relates to a method for manufacturing a steel sheet having low low-frequency iron loss according to the first aspect of the patent application, wherein the non-oriented electromagnetic steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction. And the whole steel plate contains, according to the mass%, C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and Α1: 0.1% to 8%', and the remainder is composed of Fe and unavoidable impurities. In addition, the A1 concentration (% by mass) in the thickness direction satisfies the following formula (5), namely: 0.1 &lt; (Xs - Xc) / t &lt; 100 (5) Xs : A1 concentration on the surface of the steel sheet (% by mass) Xc: A1 concentration (mass%) of the center of the steel sheet 10 t: The A1 concentration (% by mass) is the depth (mm) of the surface of the steel sheet from Xc + 0.05 (Xs_Xc). 20. The method for producing a non-oriented electrical steel sheet having a low high-frequency iron loss according to the first aspect of the invention, wherein the non-oriented electrical steel sheet having a low high-frequency iron loss has a concentration gradient of aluminum in a thickness direction, and The whole steel plate contains 15% by mass: C: 0.005% or less, Si: 2% to 4%, Μη: 1% or less, and Α1: 0.1% to 8%, and the remainder is composed of Fe and unavoidable impurities. Further, the A1 concentration (% by mass) in the thickness direction satisfies the following formula (6), namely: 0.1 &lt; (Xs' - Xc) / t &lt; 100 (6) 20 Xs' : near the surface of the steel sheet Maximum A1 concentration (mass./〇) Xc: A1 concentration (mass%) of the center of the steel plate t: The A1 concentration (% by mass) becomes the depth (mm) of the surface of the steel sheet from Xc+0.05 (Xs - Xc). 26