KR102109241B1 - Non-oriented electrical steel sheet having excellent shape property and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a non-oriented electrical steel sheet having excellent shape quality and a method for manufacturing the same.
One embodiment of the present invention in weight percent, Si: 2.8 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.005 to 0.20%, P: 0.002 to 0.15%, balance Fe and others A non-oriented electrical steel sheet having excellent shape quality that includes unavoidable impurities, and the Si, Al, Mn, Sn, and P satisfy the following relational expression 1, and the thickness deviation in the width direction of the strip (Δt _CR ) satisfies the following relational expression 2: And a method of manufacturing the same.
[Relational Formula 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4
[Relationship Formula 2] △ t _CR ≤ 36 * (S / t) ^-0.48
(In the above equation 1, Si, Al, Mn, Sn and P represent the respective contents (% by weight), in the above equation 2, Δt _CR is the thickness deviation in the width direction of the strip (µm), and S is the edge in the width direction of the strip. It is the thickness measurement position (mm) at a certain distance from, and t means the thickness of the strip (mm).)

Description

Non-oriented electrical steel sheet with excellent shape quality and its manufacturing method {NON-ORIENTED ELECTRICAL STEEL SHEET HAVING EXCELLENT SHAPE PROPERTY AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a non-oriented electrical steel sheet having excellent shape quality and a method for manufacturing the same.

2. Description of the Related Art Recently, as global environmental regulations have been strengthened due to global warming, the demand for non-oriented electrical steel sheets used for automobile driving motors and generator motors is rapidly increasing due to the increasing spread of hybrid vehicles and electric vehicles. The drive motor and the generator motor need to be installed in a limited space in the vehicle, and in order to reduce the vehicle weight, miniaturization is strongly required. In particular, among motors for automobiles, driving motors must have excellent electrical characteristics in all areas from low speed to high speed, unlike general motors, so they must generate large torque at low speed or acceleration, and have little loss during constant speed and high speed driving. In the area, suitable properties are needed.

In order to satisfy these characteristics, it is necessary to have a large magnetic flux density characteristic at low speed rotation, low frequency iron loss at high speed rotation area, and also to withstand the centrifugal force generated at high speed rotation, thereby developing a non-oriented electrical steel sheet with high strength. Is required. In addition, in manufacturing a motor, since the material is slitting and stacked after punching to produce a final part, thickness variation in the width direction, that is, appearance shape quality is very important. Therefore, the thickness in the width / length direction should be uniform.

On the other hand, as a technique for a non-oriented electrical steel sheet that improves magnetic properties, Patent Document 1 is, for example. Patent Document 1 discloses a non-oriented electrical steel sheet in which 0.1 to 5% of Co is added to steel having Si of 4% or less. In addition, in Patent Document 2, the content of P is 0.07 to 0.20%, the content of Si is 0.17 to 3.0%, hot-rolled sheet annealing is performed by box annealing with a slow cooling rate, and the aggregate structure is formed at the time of finish annealing. By controlling, a technique for achieving high magnetic flux density has been proposed. In addition, Patent Document 3 proposes a method for achieving a high magnetic flux density by setting the Al content to 0.017% or less. In Patent Document 4, a technique of adding a Sb or Sn as an element other than those described above to increase the magnetic flux density has been proposed. In addition, Patent Document 5 proposes a technique for improving magnetic properties by controlling Ti, Nb, V and B. As described above, in the case of the non-oriented electrical steel sheet, most of the techniques for controlling the alloying component to improve the magnetic properties, and the research related to the shape quality is very small.

Japanese Patent Application Publication No. 2000-129410 Japanese Patent Publication No. 3870893 Japanese Patent Publication No. 4126479 Japanese Patent Publication No. 2500033 Korean Patent Publication No. 10-2016-0078183

One aspect of the present invention is to provide a non-oriented electrical steel sheet having excellent shape quality and a method for manufacturing the same.

The subject of the present invention is not limited to the above. Any person having ordinary knowledge in the technical field to which the present invention pertains will have no difficulty in understanding additional problems of the present invention from the general contents of the present specification.

One embodiment of the present invention in weight percent, Si: 2.8 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.005 to 0.20%, P: 0.002 to 0.15%, balance Fe and others A non-oriented electrical steel sheet having excellent shape quality that includes unavoidable impurities, and the Si, Al, Mn, Sn, and P satisfy the following relational expression 1, and the thickness deviation in the width direction of the strip (Δt _CR ) satisfies the following relational expression 2: Gives

[Relational Formula 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4

[Relationship Formula 2] △ t _CR ≤ 36 * (S / t) ^-0.48

(In the above equation 1, Si, Al, Mn, Sn and P represent the respective contents (% by weight), in the above equation 2, Δt _CR is the thickness deviation in the width direction of the strip (µm), and S is the edge in the width direction of the strip. It is the thickness measurement position (mm) at a certain distance from, and t means the thickness of the strip (mm).)

Other embodiments of the present invention in weight percent, Si: 2.8 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.005 to 0.20%, P: 0.002 to 0.15%, balance Fe and others Containing unavoidable impurities, the Si, Al, Mn, Sn and P to obtain a thin slab by continuously casting a molten steel satisfying the following relationship 1; Rough rolling the thin slab to obtain a bar; Heating the bar; Hot-rolling the heated bar to obtain a hot-rolled steel sheet; And winding the hot rolled steel sheet, wherein each step is performed continuously, and cold rolling the wound hot rolled steel sheet to obtain a cold rolled steel sheet; And recrystallization annealing the cold-rolled steel sheet, and a method for manufacturing a non-oriented electrical steel sheet having excellent shape quality in which 5 to 40 L / min per 1 m 2 of lubricant is applied to the surface of the bar in the first rolling mill during the hot finish rolling. to provide.

[Relational Formula 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4

According to one aspect of the present invention, it is possible to provide an electric steel sheet having excellent shape quality and a method of manufacturing the same using a high-speed casting and a continuous rolling mode in a direct-to-rolling direct connection process.

The hot-rolled electrical steel sheet manufactured through the continuous rolling process has an excellent width deviation in the width direction compared to the existing hot-rolled electrical steel sheet manufactured through the batch process. Therefore, when manufacturing the final part, the dimensions / shape are excellent, and the materials can be uniformly stacked, making the parts easy to manufacture.

 In addition, it is possible to use steel that melts scraps of scrap metal or the like in an electric furnace through the thin slab playing method, thereby increasing the recyclability of resources.

1 is a schematic view of a facility for a direct-to-rolling direct connection process applicable to the present invention.
Figure 2 is another schematic diagram of a facility for a direct-to-roll direct connection process applicable to the present invention.
3 is a schematic view showing a thickness measurement position and a thickness deviation in a width direction at a point separated from a strip width direction edge.
4 is a schematic view for explaining the thickness variation in the width direction of the strip.
Fig. 5 shows the variation in thickness in the width direction of S / t and hot rolled material (HR material) of invention steel (Invention Examples 1 to 19), comparative steel (Comparative Examples 1 to 8), and conventional steel (Conventional Example 1).
Fig. 6 shows the variation in thickness in the width direction of the S / t of the invention steel (invention examples 1 to 19), comparative steel (comparative examples 1 to 8), and conventional steel (conventional example 1) and the final product (CR material).
Fig. 7 shows the variation in thickness in the width direction of S / t and hot-rolled material (HR material) of invention steel (Inventive Examples 20 to 25) and comparative steel (Comparative Examples 9 and 10).
Fig. 8 is the variation in thickness in the width direction of the S / t of the invention steel (invention examples 20 to 25) and comparative steel (comparative examples 9 to 12) and the final product (CR material).

Conventionally, in the existing hot rolling process, slabs having a thickness of 200 mm or more are produced through low-speed casting, and the slabs produced in this way are reheated in a heating furnace and hot rolled in batches in units of 1 to reduce the thickness. In the case of this type of batch rolling, since a top part is drawn into the rolling mill every sheet of slabs and a tail part must exit the rolling mill, an accident occurs frequently, thereby producing hot rolled and excellent electric steel sheets. There are many limitations.

The inventors of the present invention in view of the fact that in the production of electric steel sheets, when using a so-called thin slab manufacturing process (mini-mill process), in particular, continuous casting (casting) to direct rolling process, it is possible to solve the problems of manufacturing such an electric steel sheet. It came to this invention.

That is, the direct-to-rolling process is excellent in material deviation because the temperature deviation in the width and length direction of the strip is small due to the process characteristic of constant velocity isothermal. In addition, unlike the existing process, which is finished and rolled in batches for every slab or bar, in the case of a direct-to-rolling direct connection process, only the top of the first slab or bar is drawn between the rolls and rolls of the rolling mill. Significantly reducing the possibility of problems in operation accidents related to the entry of slabs or bars. In addition, since it produces products through constant-temperature isothermal rolling, it has the advantage of excellent dimensional accuracy of thickness and width compared to existing batch materials, and has the advantage of less plate crown deviation, so it was judged to be a suitable process for manufacturing hot-rolled electrical steel sheets. .

In addition, the electrical steel sheet manufactured by the direct-rolling direct-linking process as described above exhibits superior performance in terms of internal materials compared to the electrical steel sheet manufactured by a conventional batch rolling method.

Hereinafter, the electric steel sheet of the present invention and its manufacturing method will be described in detail.

 First, the alloy composition of the electric steel sheet of the present invention will be described. The alloy composition described below is based on weight percent, unless otherwise specified.

Si: 2.8 to 4.0%

Silicon (Si) is generally added as a deoxidizing agent for steel, but is an important element because it has the effect of increasing the electrical resistance and reducing iron loss at high frequencies in an electric steel sheet, and it is necessary to add 2.8% or more to obtain such an effect. However, when it exceeds 4.0%, the rolling load increases during cold rolling, which may cause shape defects. Therefore, the Si content is preferably 2.8 to 4.0%, more preferably 3.0 to 3.8%, and even more preferably 3.1 to 3.7%.

Al: 0.1-1.5%

Aluminum (Al), like Si, is generally used as a deoxidizing agent for steel, and since it is an element having a large effect of reducing iron loss by increasing electrical resistance, the addition of 0.1% or more is preferable. However, if it exceeds 1.5%, it is picked up to the mold flux during continuous casting, and the properties of the mold flux are different, so that lubrication cannot occur and casting interruption may occur. Can occur. Therefore, the Al content is preferably 0.1 to 1.5%, more preferably 0.2 to 1.3%, and even more preferably 0.3 to 1.0%.

Mn: 0.05-1.5%

Manganese (Mn) is an element that can lower the iron loss by increasing the specific resistance in the steel, so it is preferable to add 0.05% or more. However, if it exceeds 1.5%, it forms a coarse MnS precipitate by combining with S in the steel, as well as forming an austenite phase in the annealing temperature range of the present invention, and has a disadvantage that makes it difficult to coarsen grains for reducing iron loss. . Therefore, the Mn is preferably in a range of 0.05 to 1.5 %%, more preferably 0.1 to 1.3%, and even more preferably 0.2 to 1.0%.

Sn: 0.005 ~ 0.20%

Tin (Sn) is a grain boundary segregation element that suppresses the diffusion of nitrogen through the grain boundaries, suppresses the formation of {111}, {112} aggregates that are detrimental to magnetism, and increases the {100} and {110} aggregates beneficial to magnetism. It is added to improve the magnetic properties, and it is preferable to add 0.005% or more in order to increase the addition effect. However, when it is added in excess of 0.20%, grain growth is suppressed to deteriorate magnetic properties and inferior rolling properties. Therefore, the Sn content is preferably 0.005 to 0.20%, more preferably 0.01 to 0.15%, and even more preferably 0.02 to 0.10%.

P: 0.002 to 0.15%

Phosphorus (P) is an element that can increase the specific resistance in steel to lower iron loss, and is an element that can improve the magnetic flux density when added as a magnetic material, and it is preferable to add 0.002% or more for the above effect. However, when it exceeds 0.15%, it exists as a segregation element that induces rolled plate fracture at the ferrite grain boundary during rolling at room temperature, which greatly weakens the bonding force between grain boundaries. Therefore, the content of P is preferably in the range of 0.002 to 0.15%, more preferably 0.004 to 0.10%, and even more preferably 0.006 to 0.05%.

In addition, in the non-oriented electrical steel sheet of the present invention, it is preferable that the Si, Al, Mn, Sn and P satisfy the following relational expression 1. When the value of Si + Al + 0.5Mn + 0.8Sn + 5P in the relational expression 1 exceeds 5.4, the yield strength of the hot rolled material becomes too high, and the cold rolled during cold rolling has poor mailability due to the increase in rolling load, resulting in the appearance shape quality of the final product. Can fall. On the other hand, if it is less than 3.8, the content of the component is low, so the target specific resistance and yield strength of the final product may not be satisfied.

[Relational Formula 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4

(In the relational formula 1, Si, Al, Mn, Sn and P represent the respective contents (% by weight).)

The remaining component of the invention is iron (Fe). However, in the normal manufacturing process, impurities that are not intended from the raw material or the surrounding environment may be inevitably mixed, and therefore cannot be excluded. Since these impurities are known to anyone skilled in the ordinary manufacturing process, they are not specifically mentioned in this specification.

On the other hand, the electric steel sheet of the present invention, in addition to the above-mentioned alloy composition, contains at least one of C, S and N as impurities in a range of 0.05% by weight or less, and as a tram element, Nb, V, Ti, Mo, Cu , Cr, Ni, Zn, Se, Sb, Zr, W, Ga, Ge, and one or more selected from the group consisting of Mg may contain 0.2% or less. When the sum of one or more of the C, S, and N is less than 0.05% by weight, carbonitride, sulfide, and the like may be formed, resulting in a large iron loss. The tramp element is an impurity element originating from scrap used as a raw material in a steelmaking process, ladle and tundish refractory material, and when the sum exceeds 0.2%, it is liquefied at high temperature to deteriorate performance. , It can exacerbate iron loss by forming precipitates, sulfides and inclusions.

In the non-oriented electrical steel sheet of the present invention, it is preferable that the thickness deviation (Δt _CR ) in the width direction of the strip satisfies the following relational expression 2. If the following relational expression 2 is satisfied, excellent appearance shape quality can be secured. On the other hand, the smaller the value of the relational expression 2, the more excellent the appearance shape quality can be secured.

[Relationship Formula 2] △ t _CR ≤ 36 * (S / t) ^-0.48

(In the relational expression 2, Δt _CR is the thickness deviation in the width direction of the strip (µm), S is the thickness measurement position (mm) at a certain distance from the strip width direction edge, and t is the thickness of the strip (mm) box.)

The thickness of the non-oriented electrical steel sheet provided by the present invention is preferably 0.15 to 0.35 mm. When the thickness is less than 0.15 mm, productivity decreases, and when it exceeds 0.35 mm, the effect of reducing iron loss may be small, and the thickness deviation in the width direction may be severe.

In addition, the electrical steel sheet may have a specific resistance of 50 to 65 μΩ · cm, and a yield strength in the rolling horizontal direction (L direction) may be 415 MPa or more.

Hereinafter, a method for manufacturing a non-oriented electrical steel sheet according to the present invention will be described.

1 is a schematic view of a facility for a rolling-rolling direct connection process applicable to the present invention, and is a schematic view of a rolling-rolling direct-linking processing facility applicable to production of a hot rolled steel sheet of a thin material for obtaining a final electrical steel sheet. A thin electric steel sheet having excellent shape quality according to an embodiment of the present invention can be manufactured from hot-rolled steel sheets produced by applying a direct-rolling direct-equipment facility as shown in FIG. 1. The performance-rolling direct connection facility is largely composed of a continuous casting machine 100, a rough rolling machine 400, and a finishing rolling machine 600. The performance-rolling direct connection facility is a high-speed continuous casting machine 100 for producing a thin slab (a) of a first thickness, and rolling the slab into a bar (b) of a second thickness thinner than the first thickness. It may include a rough rolling mill 400, a finishing mill 600 for rolling the bar of the second thickness into a hot rolled steel sheet (c) of a third thickness, and a winder 900 for winding the hot rolled steel sheet. In addition, the rough rolling mill breaker 300 in front of the rough rolling mill 400 (Roughing Mill Scale Breaker, 'RSB') and the finishing rolling scale breaker 500 in front of the finishing mill 600 (Fishing Mill Scale Breaker, hereinafter) FSB ') may be additionally included, and it is easy to remove the surface scale, so it is possible to produce an electric steel sheet having excellent surface quality in a later process. In addition, it is possible to perform isothermal constant-speed rolling by direct-to-rolling process, so the temperature variation in the width and length of the steel sheet is remarkably low, so precise cooling control is possible in the ROT [Run Out Table (700)] (hereinafter referred to as "runout table"). It is possible to produce thin-rolled hot-rolled electrical steel sheets with excellent isotropy. The rolled and cooled hot-rolled steel sheet thus completed may be cut by a high-speed shearing machine 800 and wound up by a winding machine 900 to be produced as a product. Meanwhile, in front of the finish rolling scale breaker 500, a heater 200 for additionally heating the bar may be provided.

Figure 2 is another schematic diagram of a facility for a direct-to-roll direct connection process applicable to the present invention. The performance-rolling direct connection facility disclosed in FIG. 2 has almost the same configuration as the facility disclosed in FIG. 1, but a heater 200 ′ for additionally heating the slab in front of the rough rolling mill 400 is provided, so it is easy to secure the slab edge temperature. The occurrence of edge defects can be lowered, which is advantageous for securing the surface quality. In addition, since the space of at least one slab is secured before the rough rolling machine, batch type rolling is possible.

The hot rolled electrical steel sheet of excellent magnetic properties and shape of the present invention can be produced in both the performance and rolling direct connection facilities disclosed in FIGS. 1 and 2.

First, a molten slab having the above-described alloy composition is continuously cast to obtain a thin slab. At this time, the continuous casting is preferably performed at a casting speed of 3.5 to 8.0mpm (m / min). The reason why the casting speed is more than 3.5mpm is that a high-speed casting and a rolling process are connected, so that a certain casting speed is required to secure a target rolling temperature. When the casting speed is less than 3.5mpm, Al increases the pick-up amount to the mold flux, thereby changing the physical properties of the mold flux and reducing lubrication, which may lead to casting breakdown. If it exceeds 8.0mpm, the operation success rate may be reduced due to the instability of the molten steel bath surface. Therefore, the casting speed is preferably in the range of 3.5 to 8.0mpm, and more preferably in the range of 4.0 to 7.5mpm. , It is more preferable to have a range of 4.5 ~ 6.5mpm.

The thin slab preferably has a thickness of 80 to 120 mm. When the thickness of the thin slab exceeds 120mm, not only high-speed casting is difficult, but also increases the rolling load during rough rolling, and when it is less than 80mm, the temperature of the cast slab rapidly decreases and it is difficult to form a uniform structure. In order to solve this, it is possible to additionally install a heating facility, but this is a factor that improves the production cost, so it is desirable to exclude as much as possible. Therefore, the thickness of the thin slab is preferably controlled to 80 to 120 mm, more preferably 80 to 115 mm, and even more preferably 90 to 110 mm.

Thereafter, the continuously cast thin slab is rough-rolled to obtain a bar. At this time, the thickness of the bar is preferably 10 ~ 30mm. When the thickness of the bar exceeds 30mm, the rolling load rapidly increases with an increase in the rolling reduction during finish rolling, and the thickness variation in the width direction of the strip may increase, and if it is less than 10mm, the rolling deformation resistance becomes large, causing difficulty in operation. It is difficult to secure the temperature during finishing rolling.

On the other hand, when the rough rolling, the entrance temperature may be 1000 to 1200 ° C. When the rough rolling entry temperature is less than 1000 ° C, an increase in rough rolling load and cracks may occur at the edge of the bar. On the other hand, when the temperature exceeds 1200 ° C, the hot-rolled scale remains, and the quality of the hot-rolled surface may deteriorate.

When the rough rolling, the exit temperature may be 900 ° C or higher. This is because it is difficult to secure a finish rolling temperature when it is less than 900 ° C.

The bar is then heated. The heating temperature of the bar is preferably 900 ~ 1200 ℃. The reason for controlling the heating temperature of the bar is to stably produce a hot-rolled electrical steel sheet and to secure the surface quality. If the temperature is less than 900 ° C, the exit temperature of the finish rolling is low, and the rolling load increases rapidly, resulting in poor mailability. As a result, plate breakage may occur. When it exceeds 1200 ° C, excessive scale may be generated, and the surface quality may deteriorate.

Thereafter, the heated bar is hot-finished to obtain a hot-rolled steel sheet. The finishing rolling can be performed in a finishing rolling mill consisting of 3 to 6 stands. The finishing rolling is preferably performed at 650 to 900 ° C. When the finish rolling temperature exceeds 900 ° C, the scale may be excessively generated, thereby deteriorating the surface quality, and high temperature ductility may be too high to cause plate breakage beyond tension control. On the other hand, if it is less than 650 ° C, the strength increases rapidly, and plate breakage may occur due to poor mailability due to an increase in rolling load.

In addition, it is preferable that the average mailing speed in the last rolling during the hot finish rolling is 250 to 750 mpm. In finishing rolling, the plate speed in the final rolling mill can be directly related to the casting speed and the thickness of the hot rolled product. The plate speed in the last rolling mill, that is, when the rolling speed is more than 750mpm, may cause an operation accident such as plate breakage, and isothermal constant-speed rolling is difficult, so uniform temperature is not secured and material and thickness variations may occur. . On the other hand, if it is less than 250mpm, the final rolling speed is too slow, which may cause problems in mass balance and heat balance, making it difficult to perform continuous rolling.

In addition, it is preferable to control the speed deviation to 50 mpm or less during the production of one strip in the last rolling during the hot finish rolling. If the speed difference of the last rolling mill exceeds 50mpm, the temperature and the rolling load become non-uniform, resulting in variations in material and thickness of the hot rolled material, and in cold rolling, the variation in thickness of the final product may increase due to uneven rolling. The speed deviation is preferably 50mpm or less, more preferably 45mpm or less, and even more preferably 40mpm or less.

On the other hand, during the hot finish rolling, a lubricant may be applied to the surface of the bar to reduce the friction coefficient between the bar and the rolling rolls, thereby reducing the rolling load, thereby reducing the thickness variation. The lubricating oil is preferably applied in the first rolling mill having a very large rolling load during the hot finish rolling. The lubricating oil is preferably applied at 5 to 40 L / min per m 2 to the surface of the bar. When the application of the lubricating oil is less than 5 L / min per 1 m2, the above-described effect is insignificant, and when it exceeds 40 L / min per m2, manufacturing cost may be increased due to excessive use of the lubricant.

Thereafter, the hot rolled steel sheet is wound. The winding temperature is preferably 480 ~ 700 ℃. When the coiling temperature is less than 480 ° C, the yield strength is too high to increase the rolling load during cold rolling, which can lead to a large variation in thickness in the width direction due to poor mailability, and when it exceeds 700 ° C, the yield strength is low to form during cold rolling. Although it is advantageous for control, a secondary scale may occur, and thus quality such as roughness and surface whiteness may deteriorate.

The hot-rolled steel sheet preferably has a thickness of 1.8 mm or less. As the thickness of the steel sheet decreases, the recrystallized aggregate structure increases to ensure a uniform structure after annealing, and by reducing the cold reduction rate, the crystal orientation of γ-fiber decreases to improve magnetic properties, and the thickness deviation Can also be reduced. However, if it exceeds 1.8mm, the above effect may not be sufficient. Therefore, the thickness of the hot-rolled electrical steel sheet is preferably 1.8 mm or less, and more preferably 1.6 mm or less.

It is preferable that the thickness of the hot-rolled steel sheet in the width direction of the strip satisfies the following relational expression 3. The lower the lower Δt _HR , the better the appearance quality of the final product after cold rolling.

[Relationship 3] △ t _HR ≤ 230 * (S / t) ^-0.50

(However, △ t _HR is the thickness deviation in the width direction of the hot-rolled steel sheet (㎛), S is the thickness measurement position (mm) at a certain distance from the edge in the width direction of the hot-rolled steel sheet, t is the thickness of the hot-rolled steel sheet (mm) Meaning.)

In addition, the hot-rolled steel sheet has an average yield strength of 750 MPa or less in the rolling horizontal direction (L direction) and vertical direction (C direction), and it is preferable to satisfy the following relational expression (4). In the following equation 4, when the Si + Al + Mn / 2-t / 5 value exceeds 5.0, the yield strength of the hot-rolled electrical steel sheet exceeds 750 MPa, and the rolling load increases rapidly during cold rolling, resulting in poor mailability, resulting in the shape of the final product. This may fall, and when the Si + Al + Mn / 2-t / 5 value is less than 3.0, it may be difficult to secure the yield strength of the targeted final product.

[Relational Formula 4] 3.0 ≤ Si + Al + Mn / 2-t / 5 ≤ 5.0

(In the relational formula 4, Si, Al and Mn represent the respective contents (% by weight), and t represents the thickness (mm) of the hot-rolled steel sheet.)

On the other hand, the above-described method for manufacturing a hot-rolled steel sheet uses a continuous continuous rolling mode in a direct-rolling direct connection process, and is characterized in that each of the aforementioned processes is continuously performed.

Thereafter, the wound hot rolled steel sheet is cold rolled to obtain a cold rolled steel sheet. On the other hand, before the cold rolling may further include a step of removing the oxide layer by pickling the hot-rolled steel sheet. At this time, the pickling can be performed under normal conditions, and the pickling treatment that can be used in the present invention is not particularly limited as it is generally applicable to any treatment method used in the pickling process for electric steel.

Thereafter, the cold-rolled steel sheet is recrystallized annealed. The recrystallization annealing can also use conditions that are commonly performed in the art.

Hereinafter, the present invention will be described in more detail through examples. However, it is necessary to note that the following examples are only intended to illustrate the present invention in more detail and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by matters described in the claims and reasonably inferred therefrom.

(Example 1)

After preparing the molten steel having the alloy composition of Table 1, by applying a direct-rolling direct-linking process, the molten steel was continuously cast at a casting speed of 5.8 mpm to obtain a thin slab of 90 mm thickness, and the thin slab was roughly rolled to produce a bar. Afterwards, the bar was finished rolled under the manufacturing conditions shown in Table 2 below to prepare a hot rolled steel sheet (Hot Rolled, hereinafter HR) having a thickness of 1.2 to 1.8 mm, cold rolled at a rolling reduction rate of 79 to 85%, and 0.25 / 0.27 mm. After producing a cold rolled steel sheet having a thickness, the final product was prepared through annealing. In the annealing, annealing conditions were applied to Line Speed: 170 mpm, heating zone temperature: 780 ° C, and crack zone temperature: 850 ° C. On the other hand, in the case of the conventional example 1, after casting a 200 mm thick slab from an existing hot rolling mill, a hot rolled steel sheet having a thickness of 1.6 mm was prepared in an existing batch process under the manufacturing conditions shown in Table 2 below, and cold rolled with a reduction rate of 83%. After rolling, it was prepared as a final product having a thickness of 0.27 mm over annealing.

For the inventive examples, comparative examples, and conventional examples prepared as described above, the specific resistance, the thickness of the hot rolled material and the final product at a certain distance from the edge in the width direction of the strip [eg: edge to 25 mm, edge to 100 mm, etc.] After measuring the thickness deviation and yield strength in the width direction at, the results are shown in Table 3 below. 3 is a schematic view showing a thickness measurement position and a thickness deviation in a width direction at a point separated from a strip width direction edge.

The thickness variation in the width direction is the average of the thickness of the central portion (C _t ) in the width direction of the strip and the thickness of both edges [(E1x _t + E2x _t ) / 2], and the smaller the value, the better the appearance quality of the strip. In addition, the thickness variation in the width direction of the hot rolled material and the final product means an average value of a top portion, a middle portion, and a tail portion. 4 is a schematic view for explaining the thickness variation in the width direction of the strip.

For the yield strength, JIS 5 specimen was used, and the hot rolled material was sampled in the vertical (C direction) and horizontal direction (L direction) of rolling, measured and averaged, and the final product was rolled in the horizontal direction of the customer's requirements. The yield strength was measured for, and the results are shown in Table 3 below.

division Steel Alloy composition (% by weight) Relation 1 Si Al Mn Sn P Invention Steel 1 A 3.42 0.72 0.36 0.057 0.008 4.41 Invention Steel 2 B 3.25 0.35 0.52 0.032 0.011 3.94 Invention Steel 3 C 3.7 0.56 0.36 0.06 0.007 4.52 Invention Steel 4 D 3.1 One 0.36 0.05 0.01 4.37 Invention Steel 5 E 3.62 0.75 0.32 0.052 0.015 4.65 Invention Steel 6 F 3.15 0.95 0.62 0.045 0.01 4.5 Invention Steel 7 H 3.35 0.79 0.75 0.059 0.009 4.61 Invention Steel 8 I 3.65 1.01 0.62 0.051 0.011 5.07 Invention Steel 9 J 3.65 0.55 0.56 0.045 0.012 4.58 Invention Steel 10 K 3.8 0.56 0.35 0.039 0.016 4.65 Invention Steel 11 L 3.23 0.98 0.46 0.061 0.011 4.54 Invention Steel 12 M 3.9 0.36 0.35 0.052 0.011 4.53 Invention Steel 13 N 3.15 0.89 0.69 0.049 0.012 4.48 Comparative Steel 1 O 4.1 1.25 0.52 0.032 0.011 5.69 Comparative Steel 2 P 4.02 1.2 0.62 0.052 0.012 5.61 Comparative Steel 3 Q 4.12 0.95 0.52 0.052 0.011 5.43 Comparative steel 4 R 4.53 0.68 0.32 0.039 0.015 5.48 Comparative Steel 5 S 2.55 0.35 0.52 0.052 0.012 3.51 Comparative steel 6 T 2.65 0.25 0.36 0.045 0.011 3.42 Comparative Steel 7 U 2.42 0.55 0.5 0.049 0.015 3.61 Invention Steel 14 V 3.41 0.7 0.41 0.053 0.007 4.39 [Relational Formula 1] Si + Al + 0.5Mn + 0.8Sn + 5P

division Steel Hot rolled material
Thickness (mm) Finish rolling (thin rolling) Winding
Temperature
(℃) Cold
Rolling reduction
(%) final
product
thickness
(mm) First rolling mill
Lubricating oil flow rate
(ℓ / min per 1㎡) friction
Coefficient
(μ) Last rolling mill
Average speed
(mpm) Last rolling mill
Speed deviation
(mpm) Inventive Example 1 A 1.2 25 0.36 450 25 592 79 0.25 Inventive Example 2 1.3 25 0.35 415 26 582 79 0.27 Inventive Example 3 1.4 25 0.36 385 25 591 81 0.27 Inventive Example 4 1.6 25 0.36 335 23 600 83 0.27 Inventive Example 5 B 1.4 30 0.34 385 23 601 81 0.27 Inventive Example 6 1.6 30 0.34 335 25 589 83 0.27 Inventive Example 7 1.8 25 0.35 300 31 595 85 0.27 Inventive Example 8 C 1.4 15 0.37 385 26 589 81 0.27 Inventive Example 9 1.8 10 0.37 300 25 592 85 0.27 Inventive Example 10 D 1.4 20 0.36 385 22 589 81 0.27 Inventive Example 11 E 1.4 20 0.36 385 23 595 81 0.27 Inventive Example 12 F 1.4 20 0.36 385 22 599 81 0.27 Inventive Example 13 H 1.4 20 0.36 385 22 601 81 0.27 Inventive Example 14 I 1.4 20 0.36 385 22 596 81 0.27 Inventive Example 15 J 1.4 20 0.36 385 23 589 81 0.27 Inventive Example 16 K 1.4 30 0.36 385 21 591 81 0.27 Inventive Example 17 L 1.4 30 0.36 385 25 598 81 0.27 Inventive Example 18 M 1.4 30 0.36 385 22 585 81 0.27 Inventive Example 19 N 1.4 10 0.37 385 25 590 81 0.27 Comparative Example 1 1.4 3 0.41 385 25 860 81 0.27 Comparative Example 2 O 1.4 20 0.36 385 25 592 81 0.27 Comparative Example 3 P 1.4 15 0.37 385 24 588 81 0.27 Comparative Example 4 Q 1.4 25 0.36 385 23 594 81 0.27 Comparative Example 5 R 1.4 20 0.34 385 25 597 81 0.27 Comparative Example 6 S 1.4 24 0.33 385 22 608 81 0.27 Comparative Example 7 T 1.4 20 0.34 385 25 605 81 0.27 Comparative Example 8 U 1.4 15 0.32 385 26 601 81 0.27 Conventional Example 1 V 1.6 - - 750 200 600 83 0.27

division Resistivity
(μΩ · cm) Rolling
weight
Reduction rate
(%) Rolling
weight
Deviation
(ton) Hot rolled material Final product Width direction
Thickness deviation
(㎛) Rolling
Vertical
Horizontal direction
Average
Yield strength
(MPa) Relation 4 Width direction
Thickness deviation (㎛) Rolling
Horizontal direction
Yield strength
(MPa) 25
mm 100
mm 200
mm 300
mm 25
mm 50
mm 100
mm 200
mm Inventive Example 1 56 15 49 28 9 4 3 669 4.1 1.50 1.25 1.05 0.50 444 Inventive Example 2 56 15 51 29 10 5 4 667 4.1 1.60 1.50 1.06 0.71 442 Inventive Example 3 56 15 50 31 11 7 4 666 4.0 1.80 1.62 1.55 1.15 439 Inventive Example 4 56 15 48 35 14 9 4 663 4.0 2.10 1.95 1.71 1.21 438 Inventive Example 5 53 18 48 32 12 8 3 627 3.6 1.70 1.59 1.51 1.02 431 Inventive Example 6 53 19 45 35 15 9 5 624 3.5 2.20 2.01 1.82 1.35 435 Inventive Example 7 53 15 56 41 21 14 8 621 3.5 3.00 2.86 2.13 1.68 429 Inventive Example 8 59 12 49 31 11 5 3 680 4.2 2.10 1.85 1.75 1.26 452 Inventive Example 9 59 9 47 45 23 13 6 674 4.1 2.90 2.55 2.25 1.68 447 Inventive Example 10 55 13 48 30 11 6 4 656 4.0 1.70 1.45 1.32 0.82 445 Inventive Example 11 60 13 49 32 12 7 3 685 4.3 1.80 1.62 1.52 1.09 451 Inventive Example 12 58 13 48 32 13 8 3 666 4.1 1.70 1.45 1.32 0.75 446 Inventive Example 13 56 13 48 33 12 6 3 678 4.2 1.80 1.52 145 0.85 449 Inventive Example 14 64 13 48 38 18 10 7 718 4.7 1.80 1.67 1.32 0.79 464 Inventive Example 15 57 13 49 31 11 7 4 682 4.2 1.90 1.75 1.53 0.95 449 Inventive Example 16 60 19 46 32 12 6 4 689 4.3 2.00 1.91 1.78 1.32 452 Inventive Example 17 61 19 47 30 11 5 3 670 4.2 1.90 1.85 1.66 1.16 452 Inventive Example 18 58 19 43 29 10 6 4 684 4.2 1.80 1.68 1.52 1.02 447 Inventive Example 19 57 10 47 31 12 7 5 664 4.1 1.80 1.61 1.43 0.95 443 Comparative Example 1 57 3 51 63 38 32 15 669 4.1 4.31 3.51 2.69 1.89 446 Comparative Example 2 69 13 47 51 32 25 14 775 5.3 4.55 3.58 2.70 2.05 482 Comparative Example 3 70 12 47 60 39 31 14 768 5.3 4.40 3.45 2.61 1.95 492 Comparative Example 4 68 15 46 53 32 25 15 755 5.1 4.20 3.41 2.52 2.09 473 Comparative Example 5 67 13 47 58 38 31 14 767 5.1 4.25 3.42 2.56 1.94 475 Comparative Example 6 45 14 42 29 10 6 4 561 2.9 1.80 1.62 1.51 1.01 401 Comparative Example 7 44 13 45 31 11 5 4 557 2.8 1.70 1.53 1.34 0.85 395 Comparative Example 8 46 12 47 30 13 7 4 563 2.9 1.70 1.52 1.35 0.75 405 Conventional Example 1 56 - 1600 59 39 29 15 642 4.0 5.90 3.82 2.61 2.01 425 [Relational Formula 4] Si + Al + Mn / 2-t / 5

As can be seen from Tables 1 to 3, Inventive Examples 1 to 19 satisfying all of the alloy composition, component relations, and manufacturing conditions proposed in the present invention satisfy both the widthwise thickness deviation and yield strength of the targeted hot rolled material. , It can also be seen that both the thickness deviation and yield strength in the width direction of the final product are satisfied. In addition, in the case of the invention examples 1 to 19, the thickness variation (crown) in the width direction of the hot rolled material is significantly lower than in the conventional example 1, and it can be seen that the thickness variation in the width direction of the final product is also very small. Therefore, it can be seen that in the case of Inventive Examples 1 to 19, the appearance shape quality is superior to that of the conventional example 1.

In Comparative Example 1, it can be seen that in the finish rolling proposed by the present invention, the amount of lubricant applied in the first rolling mill was not satisfied, and thus the rolling load was high and the target thickness deviation in the width direction was not satisfied.

In Comparative Examples 2 to 5, the Si + Al + 0.5Mn + 0.8Sn + 5P value in relation (11) exceeded 5.4, as well as the case where the relational expression (4) was not satisfied, and the thickness variation in the width direction was severe and yield strength of the hot rolled material It can be seen that it is high.

In Comparative Examples 6 to 8, the Si + Al + 0.5Mn + 0.8Sn + 5P value in the relational expression 1 is less than 3.8, and the relational expression 4 is not satisfied, and the target specific resistance and yield strength of the final product are not satisfied. You can see that you can't.

On the other hand, Figure 5 is a graph examining the correlation between the thickness deviation in the width direction of the S / t and the hot rolled material for Inventive Examples 1 to 19, Comparative Examples 1 to 8, and Conventional Example 1. As can be seen in Figure 5, the S / t of the invention steel (Invention Examples 1 to 19) and the thickness deviation in the width direction have the same relationship as in Equation 1, and the comparative steel (Comparative Examples 2 to 5) has the same relationship as in Equation 2 It can be seen that the prior art example 1 has the same relationship as the derivation equation 3.

[Extraction Formula 1] Inventive Example Width Deviation in Thickness (△ t _HR ) = 373 * (S / t) ^-0.82

[Extraction Formula 2] Comparative Example Width Deviation in Width (△ t _HR ) = 231 * (S / t) ^-0.47

[Extraction Type 3] Conventional Example Width Deviation in Width (△ t _HR ) = 241 * (S / t) ^-0.49

(The S is a thickness measurement position (mm) at a certain distance from the edge in the width direction of the hot-rolled steel sheet, and t means the thickness (mm) of the hot-rolled steel sheet.)

From the relationship between Tables 3 and 5 and derivation formulas 1 to 3, it can be seen that the strips produced in the present invention have superior appearance quality compared to Comparative Examples and Conventional Examples 1. Therefore, in the case of the invention example, it is preferable to satisfy the following relational expression 3 in order to improve the appearance shape quality compared to the conventional example 1.

6 is a graph examining the correlation between S / t and the thickness deviation in the width direction of the final product for Inventive Examples 1 to 19, Comparative Examples 1 to 8, and Conventional Example 1. From this result, the S / t of the invention steel (Inventive Examples 1 to 19) and the thickness deviation in the width direction have the same relationship as in Equation 4, and the comparative steels (Comparative Examples 2 to 5) have the same relationship as in Equation 5, It can be seen that the prior art example 1 has the same relationship as the derivation equation 6.

[Extraction Formula 4] Thickness deviation in the width direction of the invention steel (△ t _CR ) = 7.5 * (S / t) ^-0.29

[Extraction Formula 5] Comparative steel width direction thickness deviation (△ t _CR ) = 36 * (S / t) ^-0.46

[Extraction Formula 6] Thickness deviation in the width direction of conventional steel (△ t _CR ) = 60 * (S / t) ^-0.49

(The S is the thickness measurement position (mm) at a certain distance from the edge in the strip width direction, t means the thickness (mm) of the strip.)

(Example 2)

In relation to the invention steel 1 (steel type A) of Example 1, the relationship between the speed deviation of the first rolling mill in the finish rolling, the thickness deviation in the width direction of the hot rolled material according to the winding temperature, the yield strength, and the thickness deviation in the width direction of the final product, The results are shown in Tables 4 and 5 below.

division Steel Hot rolled material
Thickness (mm) Finish Rolling (Thin Rolling) Winding
Temperature
(℃) Final product
thickness
(mm) First rolling mill entry
Lubricant flow rate (ℓ / min per 1㎡) Coefficient of friction
(μ) Last rolling
Speed difference (mpm) Inventive Example 20 A 1.4 20 0.36 26 601 0.27 Inventive Example 21 1.4 20 0.36 30 595 0.27 Inventive Example 22 1.4 15 0.37 35 605 0.27 Comparative Example 9 1.4 25 0.36 62 592 0.27 Comparative Example 10 1.4 20 0.36 85 600 0.27 Invention Steel 23 1.4 20 0.36 27 552 0.27 Invention Steel 24 1.4 25 0.36 26 515 0.27 Comparative Example 11 1.4 15 0.37 27 440 0.27 Comparative Example 12 1.4 20 0.36 28 462 0.27 Inventive Example 25 1.4 20 0.36 27 486 0.27

division Pressed load
Reduction rate
(%) Rolling load
Deviation
(ton) Hot rolled material Final product Thickness deviation in width direction (㎛) With rolling vertical
Average in horizontal direction
Yield strength
(MPa) Thickness deviation in width direction (㎛) 25
mm 100
mm 200
mm 300
mm 25
mm 50
mm 100
mm 200
mm Inventive Example 20 13 47 30 11 6 5 665 1.91 1.62 1.55 1.15 Inventive Example 21 13 55 32 12 7 4 664 2.02 1.62 1.55 1.14 Inventive Example 22 12 61 35 14 8 6 665 2.05 1.75 1.62 1.26 Comparative Example 9 15 87 59 35 26 18 669 4.31 3.30 2.79 1.90 Comparative Example 10 13 105 68 59 37 16 672 4.72 3.35 2.88 2.08 Invention Steel 23 13 49 31 12 6 4 692 2.21 1.62 1.55 1.15 Invention Steel 24 15 48 32 11 7 4 705 2.51 2.55 2.15 1.78 Comparative Example 11 12 48 31 12 6 5 761 4.23 3.39 2.79 1.94 Comparative Example 12 12 49 32 13 9 6 752 4.45 3.39 2.92 1.85 Inventive Example 25 13 48 32 14 11 6 730 3.35 2.75 1.97 1.35

As can be seen from Tables 4 and 5, Inventive Examples 20 to 25 satisfying all of the alloy composition, component relations, and manufacturing conditions proposed in the present invention satisfy both the widthwise thickness deviation and yield strength of the targeted hot rolled material. , It can also be seen that both the thickness deviation and yield strength in the width direction of the final product are satisfied.

As Comparative Examples 9 and 10 do not satisfy the speed variation in the final rolling mill proposed in the present invention, it can be seen that the thickness variation in the width direction of the hot rolled material and the final product is severe.

As Comparative Examples 11 and 12 do not satisfy the winding temperature proposed in the present invention, it can be seen that the average value of yield strength in the rolling horizontal direction (L direction) and the vertical direction (C direction) of the hot rolled material is high. It can be seen that the thickness variation in the width direction of the final product is severe.

7 and 8 are graphs examining the correlation between the S / t of Inventive Examples 20 to 25 and Comparative Examples 9 to 12 and the thickness deviation in the width direction of the hot rolled material and the final product, respectively. As can be seen from this result, in the case of the invention example that satisfies the speed deviation and winding temperature in the last rolling machine proposed in the present invention, relations 2 and 3 are satisfied, but comparative examples 9 to 12 do not satisfy relations 2 and 3, It can be seen that the thickness variation in the width direction is severe.

a: slab b: bar
c: hot rolled steel sheet
100: continuous casting machine 200, 200 ': heater
300: RSB (Roughing Mill Scale Breaker)
400: rough rolling mill
500: FSB (Fishing Mill Scale Breaker)
502: cooling water spray nozzle
504: coolant
600: finishing mill 700: runout table
800: High-speed shearing machine 900: Winding machine

Claims (19)

In weight percent, Si: 2.8 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.005 to 0.20%, P: 0.002 to 0.15%, balance Fe and other unavoidable impurities.
The Si, Al, Mn, Sn and P satisfy the following relationship 1,
The thickness deviation (△ t _CR ) in the width direction of the strip is a non-oriented electrical steel sheet having excellent shape quality that satisfies the following relational expression 2.
[Relational Formula 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4
[Relationship Formula 2] △ t _CR ≤ 36 * (S / t) ^-0.48
(In the above equation 1, Si, Al, Mn, Sn and P represent the respective contents (% by weight), in the above equation 2, Δt _CR is the thickness deviation in the width direction of the strip (µm), and S is the edge in the width direction of the strip. It is the thickness measurement position (mm) at a certain distance from, and t means the thickness of the strip (mm).)
The method according to claim 1,
The electrical steel sheet contains at least one of C, S and N as impurities in a range of 0.05% by weight or less, and as a tram element, Nb, V, Ti, Mo, Cu, Cr, Ni, Zn, Se, Sb, Zr, W, Ga, Ge, and one or more types selected from the group consisting of Mg is a non-oriented electrical steel sheet excellent in shape quality with a total sum of 0.2% or less.
The method according to claim 1,
The electrical steel sheet is a non-oriented electrical steel sheet having excellent shape quality with a thickness of 0.15 to 0.35 mm.
The method according to claim 1,
The electrical steel sheet is a non-oriented electrical steel sheet having excellent shape quality with a specific resistance of 50 to 65 μΩ · cm.
The method according to claim 1,
The electrical steel sheet is a non-oriented electrical steel sheet having excellent shape quality in a yield strength of 415 MPa or higher in the rolling horizontal direction (L direction).
In weight percent, Si: 2.8 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.005 to 0.20%, P: 0.002 to 0.15%, balance Fe and other unavoidable impurities. Si, Al, Mn, Sn and P is a step of continuously casting a molten steel satisfying the following formula 1 to obtain a thin slab;
Rough rolling the thin slab to obtain a bar;
Heating the bar;
Hot-rolling the heated bar to obtain a hot-rolled steel sheet; And
Winding the hot rolled steel sheet,
Each of the above steps is performed continuously,
Cold rolling the wound hot rolled steel sheet to obtain a cold rolled steel sheet; And
And recrystallization annealing the cold rolled steel sheet,
A method of manufacturing a non-oriented electrical steel sheet having excellent shape quality in which 5 to 40 L / min per 1 m2 of lubricant is applied to the surface of the bar in the first rolling mill during the hot finish rolling.
[Relationship 1] 3.8 ≤ Si + Al + 0.5Mn + 0.8Sn + 5P ≤ 5.4
The method according to claim 6,
The molten steel contains, as an impurity, one or more of C, S, and N in a total range of 0.05% by weight or less, and as a tram element, Nb, V, Ti, Mo, Cu, Cr, Ni, Zn, Se, Sb , Zr, W, Ga, Ge, and one or more types selected from the group consisting of Mg.
The method according to claim 6,
The continuous casting method is a non-oriented electrical steel sheet having excellent shape quality performed at a casting speed of 3.5 to 8.5 mpm.
The method according to claim 6,
The thin slab is a non-oriented electrical steel sheet having excellent shape quality with a thickness of 80 to 120 mm.
The method according to claim 6,
The method for manufacturing a non-oriented electrical steel sheet having excellent shape quality with a temperature of 1000 to 1200 ° C when the rough rolling is performed.
The method according to claim 6,
The method for manufacturing a non-oriented electrical steel sheet having excellent shape quality at a temperature of 900 ° C or higher during rough rolling.
The method according to claim 6,
Method for manufacturing a non-oriented electrical steel sheet having excellent shape quality with a heating temperature of 900 to 1200 ° C.
The method according to claim 6,
The finish rolling is a method of manufacturing a non-oriented electrical steel sheet having excellent shape quality performed at 650 to 900 ° C.
The method according to claim 6,
The method of manufacturing a non-oriented electrical steel sheet having excellent shape quality in the average rolling speed at the time of the final rolling during the final rolling is 250 to 750 mpm.
The method according to claim 6,
The method of manufacturing a non-oriented electrical steel sheet having excellent shape quality in which the speed deviation in the final rolling mill during finishing rolling is 50 mpm or less.
The method according to claim 6,
The winding is a non-oriented electrical steel sheet manufacturing method excellent in shape quality is performed at 480 ~ 700 ℃.
The method according to claim 6,
The hot-rolled steel sheet is a non-oriented electrical steel sheet having excellent shape quality with a thickness of 1.8 mm or less.
The method according to claim 6,
The hot-rolled steel sheet is a method of manufacturing a non-oriented electrical steel sheet having excellent shape quality in which the thickness deviation of the strip in the width direction satisfies relational expression 3 below.
[Relationship 3] △ t _HR ≤ 230 * (S / t) ^-0.50
(However, △ t _HR is the thickness deviation in the width direction of the hot-rolled steel sheet (㎛), S is the thickness measurement position (mm) at a certain distance from the edge in the width direction of the hot-rolled steel sheet, t is the thickness of the hot-rolled steel sheet (mm) Meaning.)
The method according to claim 6,
The hot-rolled steel sheet is a method of manufacturing a non-oriented electrical steel sheet having an excellent yield strength of 750 MPa or less in a rolling horizontal direction (L direction) and a vertical direction (C direction), and satisfying the following relational expression 4.
[Relational Formula 4] 3.0 ≤ Si + Al + Mn / 2-t / 5 ≤ 5.0
(In the relational formula 4, Si, Al and Mn represent the respective contents (% by weight), and t represents the thickness (mm) of the hot-rolled steel sheet.)

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