JP2002361314A - Apparatus and method for continuous heat treatment of hot-rolled plate of grain oriented silicon steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line and method for continuous heat treatment of a hot-rolled strip of a grain oriented silicon steel capable of stably performing the continuous heat treatment with a high grade. SOLUTION: In the apparatus for continuous heat treatment of the hot-rolled plate of the grain oriented silicon steel, the apparatus comprises a rolling mill 6 to reduce the wall thickness of the hot-rolled strip, a furnace 8 to anneal the strip whose wall thickness is reduced and which is delivered from the rolling mill, and a pickling unit 9 to remove scales of the annealed strip delivered from the furnace portion. The continuous treatment line includes a cold rolling mill in the upstream of the furnace in addition to the conventional hot-rolled plate annealing and pickling line having the furnace and the pickling portion. This treatment method stabilizes not only the quality of the hot-rolled plate but also minimizes wall thickness variations along the longitudinal direction of the strip before annealing the hot-rolled plate, and further, uniformizes annealing conditions of the hot-rolled plate to achieve high productivity and high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing oriented silicon steel, particularly a thin oriented (less than 0.23 mm) oriented silicon steel of a final product produced by a single cold rolling process under high pressure. In the line for continuous heat treatment of directional silicon steel hot-rolled sheets that can be produced with high quality and stability, a rolling step of cold-rolling hot-rolled sheets before annealing is added to the annealing and pickling steps. The present invention relates to a continuous heat treatment facility.

[0002]

2. Description of the Related Art Hot-rolled directional silicon steel (hot-rolled sheet)
The most widely used procedure for once-under-high pressure cold rolling to obtain a high quality final product (sheet thickness of more than 0.23 mm) comprises the following processes. That is, (1) hot rolled sheet annealing and pickling, (2) cold rolling, (3) decarburizing annealing, (4) high temperature annealing, and (5) shape correction annealing. At this time, in general, the thickness of the hot-rolled sheet is such that the rate of reduction in the thickness of the cold-rolled sheet is 80 to 9%.
The nominal value is usually 2 to 3 mm so as to be 0%, and a reverse type monoblock type 20-high rolling mill is often used for cold rolling.

Further, as a method of manufacturing a high-quality final product having a small thickness, the following two methods are adopted. (1) The thickness of the hot-rolled sheet is further reduced, and the rate of reduction in the thickness of the cold-rolled sheet is secured at 80 to 90%. (2) The cold rolling is divided into two, and the first cold rolling (preliminary cold rolling) is performed before hot-rolled sheet annealing, and the thickness reduction rate of the preliminary cold rolling is set to 15 to 40%. The reduction rate of the cold-rolled sheet thickness after annealing is set to 80 to 90%.

[0004] In any of the methods, when the reduction ratio of the thickness of the cold-rolled sheet after hot-rolled sheet annealing exceeds 90%, the (110) plane strength decreases in the texture after decarburizing annealing, and fine grains become abnormal. This is because iron loss is deteriorated. On the other hand, when it is less than 80%, the magnetic flux density decreases and the iron loss increases. In addition, when the sheet thickness reduction rate of the pre-cold rolling exceeds 40%, the magnetic flux density decreases and iron loss deteriorates.
This is because there are many abnormalities in the linear fine particles and iron loss is deteriorated. Further, in cold rolling, rolling is performed by a reverse mill at an intermediate pass at a temperature of 50 to 300 ° C. with the aim of improving magnetism by an aging effect for each pass. This is particularly necessary for products having a small thickness of the final product.

[0005]

These approaches have several disadvantages. First, in the method (1), first, a hot rolled sheet having a smaller thickness is more expensive. Second, as the thickness of the hot-rolled sheet decreases, the absolute temperature of the finish decreases, and the temperature difference from one end of the strip to the other increases. The decrease becomes very large, and the precipitation of the inhibitor occurs in the hot rolling stage, the hot rolled sheet material itself becomes abnormal,
Frequently does not recrystallize. Third, the thickness of the hot-rolled sheet also changes at a large rate, and it is difficult to perform subsequent annealing uniformly, and as a result, secondary recrystallization becomes unstable. In particular, in the case of a thin product of the final product, the second,
And the third disadvantage becomes more pronounced.

In the method (2), cold rolling is divided into two processes. As a result, the number of manufacturing processes (an acid pickling process and a pre-cold rolling process) is increased, and the manufacturing cost is significantly increased. Have been forced. In addition, by performing all the cold rolling passes by the reverse mill, the productivity of the cold rolling must be lowered. In this way, regardless of the plan, it is possible to manufacture a product having a small thickness of the final product while ensuring high productivity while maintaining high quality and stability.
It is difficult and new facilities and methods are eagerly needed.

According to the present invention, a cold rolling step is provided upstream of a conventional hot-rolled sheet annealing / pickling step so that the thickness of the hot-rolled sheet is kept constant (not excessively thin). An object of the present invention is to provide a facility and a method for performing high-quality, stable and continuous heat treatment of hot-rolled directional silicon steel strip by focusing on not increasing the process.

[0008]

The gist of the present invention is as follows: (1) In a continuous heat treatment facility for hot-rolled sheets of directional silicon steel, a pay-off reel for unwinding a hot-rolled coil, and a strip plate A rolling mill for reducing the thickness, a furnace section for annealing the reduced thickness strip coming out of the rolling mill, and a scale for removing the scale of the annealed strip leaving the furnace section. A continuous heat treatment facility for hot-rolled directional silicon steel sheets, comprising a pickling section and a tension reel for rewinding a pickled coil. (2) In the continuous heat treatment equipment for hot-rolled sheets according to (1), the rolling mill is a split-type 20-high rolling mill and / or
A continuous heat treatment facility for hot-rolled directional silicon steel sheets, which is selected from the class consisting of two-high rolling mills. (3) In the continuous heat treatment equipment for hot-rolled sheets according to (1) or (2), a mechanical descaling device for removing scale on a strip surface generated during hot rolling is disposed upstream of the rolling mill. A continuous heat treatment facility for hot-rolled sheets of directional silicon steel, characterized in that: (4) In the continuous heat treatment equipment for hot-rolled sheets according to (3), the mechanical descaling device is selected from a bending roller and / or shot blasting. Continuous heat treatment equipment. (5) In the continuous heat treatment equipment for hot-rolled sheets according to any one of (1) to (4), a second rolling mill for further reducing the thickness of the strip is disposed downstream of the pickling section. A continuous heat treatment facility for hot-rolled sheets of directional silicon steel, characterized in that: (6) In the continuous heat treatment equipment treatment line for a hot-rolled sheet according to (5), the second rolling mill is a split-type 20-high rolling mill,
And / or a continuous heat treatment equipment for hot rolled sheets of directional silicon steel, which is selected from the class consisting of 12-high rolling mills. (7) The directional silicon according to (5) or (6), wherein the unit tension at the time of rewinding the coil on the tension reel is set to 100 to 250 MPa. Continuous heat treatment equipment for hot rolled steel sheets. (8) The directional silicon steel according to any one of (5) to (7), wherein the sheet temperature of the coil on the tension reel is 150 to 250 ° C. Continuous heat treatment equipment for hot rolled sheets. (9) In a continuous heat treatment method for a hot-rolled sheet of directional silicon steel, a step of unwinding a hot-rolled coil in one continuous processing line, and a method for reducing a thickness of the strip. A cold rolling step, a step of annealing the strip having a reduced thickness, a step of pickling the annealed strip, and a step of rewinding the pickled coil. Heat treatment method for hot rolled sheet of directional silicon steel. (10) In the method for continuously heat-treating a hot-rolled sheet according to (9), the cold-rolling step includes a split-type 20-high rolling mill, and / or
Alternatively, a method for continuously heat-treating a hot-rolled sheet of directional silicon steel, characterized by being rolled by a 12-high rolling mill. (11) The method for continuous heat treatment of a hot-rolled sheet according to (9) or (10), further comprising a step of performing mechanical descaling upstream of the cold rolling step in the line. A continuous heat treatment method for hot-rolled silicon steel sheets. (12) In the method for continuously heat-treating a hot-rolled sheet according to (11), the mechanical descaling step is performed by a treatment using a bending roller and / or a shot blast. A continuous heat treatment method for rolled sheets. (13) The method for continuous heat treatment of a hot-rolled sheet according to any one of (9) to (12), wherein the thickness of the pickled strip is further reduced downstream of an annealing step in the line. A continuous heat treatment method for a hot rolled sheet of directional silicon steel, comprising the second cold rolling step. (14) In the method for continuously heat-treating a hot-rolled sheet according to (13), the second cold rolling step includes providing a split type 20-high rolling mill and / or a 12-high rolling mill. Continuous heat treatment method for hot rolled sheet of resistant silicon steel. (15) The method for continuously heat-treating a hot-rolled sheet according to (13) or (14), wherein the unit tension is 100 to 25.
A method for continuously heat-treating a hot-rolled sheet of directional silicon steel, the method comprising rewinding at 0 MPa. (16) The method for continuously heat-treating a hot-rolled sheet according to any one of (13) to (15), wherein the sheet temperature is 150 to 250 ° C.
A method for continuously heat-treating a hot-rolled sheet of directional silicon steel, comprising: (17) The continuous heat treatment method for a hot-rolled sheet of directional silicon steel according to the continuous heat treatment method for a hot-rolled sheet according to (16), wherein the rewinding coil is further subjected to tandem cold rolling. It is.

[0009]

FIG. 1 is a semi-schematic isometric view of a typical prior art continuous heat treatment facility for annealing and pickling a hot rolled sheet of grain-oriented silicon steel. It should be understood that such lines are actually more complex than shown. For example, the furnace section typically comprises a heating zone, a soaking zone, and a cooling zone, and the pickling section typically comprises several tanks containing pickling chemicals (such as HCL) and the chemicals. It consists of washing and drying equipment to remove the water. This line may also have a mechanical descaling device such as a shot blast facility upstream of the pickling tank.

However, the main elements of such a line are the pay-off reel 1 for loading and unwinding the coil 60 of directional silicon steel that has been hot-rolled, and the end of the coil. Incoming shear 2 for cutting and preparing for welding, welding machine 3 for joining continuous coil ends, slowing down furnace and pickling during coil preparation and welding An entry storage looper 4 for storing strips that can be passed without stopping,
Furnace section 8 consisting of a heating, soaking and cooling device used for annealing the strip, a pickling tank used for removing scale from the surface of the strip, and a pickling device consisting of a cleaning device for cleaning the strip. Section 9, when the coil rewinding is completed, when the outlet shearing machine 14 is operating, the coil stores a strip that allows the furnace section 8 and the pickling section 9 to pass without decelerating and stopping. Side storage looper 12, outlet shearer 14, and
And a tension reel 16 for rewinding the coil. Bridle rolls 21a, 21b, 22a, 22b, 27a, 27b, 2
9a and 29b are arranged to secure the strip tension before and after the bridle.

FIG. 2 is a semi-schematic isometric view of a typical annealing and pickling line for hot rolled directional silicon steel according to one embodiment of the present invention. Although separated into two stages, they are actually continuous as lines. FIG.
In comparison with the conventional line, the position of the cold rolling mill 6 between the entrance storage looper 4 and the furnace section 8 in the line,
Leveler 13, central storage looper 7, and bridle rolls 23a, 23b, 23c, 23d, 24
a and 24b are provided.

In the position between the looper 4 and the furnace section 8, the strip 60 is cold-rolled without stopping even when the entry side welding machine 3 is operating. The work rolls and the like of the cold rolling mill 6 are replaced when the rolls are worn or scratched, but at this time, the processing can be performed without stopping the line in the furnace 8 or decelerating. The other parts of the line shown in FIG. 2 are similar to the line of FIG. 1, and the same parts or devices are given the same numbers.

The conditions for the cold rolling mill 6 are as follows.
(i) The thickness reduction rate can be reduced by 15 to 40%, and (ii) the thickness variation after cold rolling is small.
(iii) Roll exchange must be easy.

In order to satisfy (i) efficiently, the work roll diameter of the rolling mill is preferably in the range of 60 to 150 mm. If the work roll diameter is less than 60 mm, the work roll of the rolling mill will be worn out in a short time, and the work roll will be replaced every few coils, which is not practical. On the other hand, when the work roll diameter exceeds 150 mm, the capacity and the number of rolling mills increase, which is inefficient.

The most effective means for improving (ii) is a cold rolling mill having high mill rigidity. Desirably, the mill stiffness is 300 tons / mm or more. If the thickness is less than 300 tons / mm, it is difficult to eliminate the thickness variation of the hot-rolled sheet, especially so-called skid marks, and the heat treatment of the hot-rolled sheet, which is the object of the present invention, cannot be performed uniformly over the entire length of the coil. It is.

As a cold rolling mill that satisfies (iii), a split type cold rolling mill in which at least one of the upper housing and the lower housing is large and can be moved in the vertical direction when the work roll is replaced is effective.

As described above, the cold rolling mill 6 is a split-type 20-high rolling mill having high mill rigidity and / or
A two-high rolling mill is preferred. That is, one or a plurality of split type 20-high rolling mills or 12-high rolling mills,
Alternatively, both a split type 20-high rolling mill and a 12-high rolling mill may be provided. The number of the cold rolling mills 6 is determined based on a required thickness reduction rate or the like.
In general, one unit is used if the number is below, and two units are generally used if the number is more than one.

FIG. 3 is another embodiment of the present invention.
FIG. 4 is a semi-schematic isometric view of a typical annealing / pickling line of a hot-rolled sheet of directional silicon steel, which is separated into two stages for drawing but is actually continuous. A mechanical descaling device is disposed upstream of the cold rolling mill 6, and a second cold rolling mill 11 downstream of the pickling unit 9, and
It is the same as the line in FIG. 2 of the above-described embodiment of the present invention, except that bridle rolls 28a to 28d are arranged.

The mechanical deskering device cracks the scale on the surface of the hot-rolled sheet before entering the cold rolling mill 6, and effectively removes the scale during the rolling by the cold rolling mill 6, so that the scale is more scratched. Enables cold rolling without generation.
In this apparatus, descaling can be more effectively performed by combining the bending roller 10 and the shot blast 5, and in some cases, these can be arranged alone or in plurals.

The condition of the second cold rolling mill 11 is that the hot-rolled sheet can be reduced by (i) a sheet thickness reduction rate of 45 to 55%, and (ii) sheet thickness fluctuation after cold rolling. It is necessary that the value is small and (iii) the roll exchange is easy.

In order to satisfy (i) efficiently, the work roll diameter of the rolling mill is desirably 60 to 150 mm. If the work roll diameter is less than 60 mm, the work roll of the rolling mill will be worn out in a short time, and the work roll will be replaced every few coils, which is not practical. On the other hand, if it exceeds 150 mm, the capacity and the number of rolling mills increase, which is inefficient.

The most effective means for improving (ii) is a cold rolling mill with high mill rigidity. Desirably, the mill stiffness is 300 tons / mm or more. If the thickness is less than 300 tons / mm, it is difficult to reduce the thickness variation of the cold-rolled sheet.

As a cold rolling mill that satisfies (iii), a split-type cold rolling mill in which at least one of the upper housing and the lower housing is large when the work roll is replaced and can be moved in the vertical direction is effective.

From the above, the second cold rolling mill 1
1 is also preferably a split-type 20-high rolling mill and / or a 12-high rolling mill having high mill rigidity. That is, one or a plurality of split type 20-high rolling mills or 12 high-speed rolling mills, or both a split 20-high rolling mill and a 12-high rolling mill may be provided. The number of the second cold rolling mills 11 is determined by the number of aging passes required for each pass thereafter, the thickness reduction rate required for 3 to 4 passes, and the like, but two rolls are generally used. .

In the embodiment shown in FIG. 2, it is also possible to install a mechanical deskering device upstream of the cold rolling mill 6. This mechanical deskelling device includes a bending roller 1 as shown in FIG.
It is appropriately selected from a combination of 0 and shot blast 5 or a single one and the like.

FIG. 4 is a semi-schematic isometric view of a typical annealing and pickling line of a hot-rolled sheet of grain-oriented silicon steel, which is another embodiment of the present invention. Although separated into stages, they are actually continuous. The running shears 17 as the output shears and the carousel tension reels 1 as the tension reels for rewinding the coil.
8 of the example of the present invention, except that
Is the same as the line.

By doing so, the second cold rolling mill 1
1, the sheet temperature after cold rolling is kept high, and 150 to 250
The structure is such that it can be re-wound around the reels 19a and 19b at a temperature of ° C. The reason why the film is wound on a reel at 150 to 250 ° C. is that if the temperature is lower than 150 ° C., the aging effect per pass in the so-called cold rolling intermediate pass is insufficient, and the improvement of magnetism is not sufficient. On the other hand, at a temperature higher than 250 ° C., the quality of the rolling oil remaining on the strip after being wound on the reel is significantly altered, seizure is not removed by the subsequent tandem rolling,
This is because it becomes a pattern or a scratch.

In the case of rewinding, it is necessary to wind it on a reel at a unit tension of 100 to 250 MPa. If the pressure is less than 100 MPa, in the subsequent tandem rolling, sufficient back tension cannot be obtained and a sufficient rolling reduction cannot be obtained. On the other hand, if it exceeds 250 MPa, the tightening of the reel at the time of rewinding is large, and it becomes difficult to manufacture the reel.

In any of the inventions, the hot rolling finish temperature of the hot rolled sheet can be kept uniform and high.
The thickness of the hot-rolled sheet during annealing becomes more uniform, and as a result, the annealing conditions can be made more uniform, and extremely high-grade and stable directional silicon steel with a small thickness of the final product can be manufactured. . The present invention is not limited to the one-time cold rolling method under high pressure, but is also effective in the production of directional silicon steel by the two-time cold rolling method in which hot-rolled sheet annealing is performed.

[0030]

EXAMPLES [Example 1] In mass%, C: 0.005%,
Si: 3.25%, Mn: 0.1%, S: 0.007
%, Al: 0.027%, N: 0.0070%, and Sn: 0.07% A slab of grain-oriented silicon steel was heated at a low temperature of 1150 ° C., and then the plate thickness was 2.3 mm.
Hot rolled coil. This hot-rolled coil was processed in a continuous annealing / pickling line of a hot-rolled sheet according to the present invention shown in FIG. First, the thickness was reduced to a thickness of 1.8 mm (a thickness reduction rate of 22%) using a split-type 20-high rolling mill having a work roll diameter of 90 mm, then annealed at 1100 ° C, and then pickled. The mill rigidity was 350 tons / mm. Thereafter, a final thickness of 0.18 mm (thickness reduction rate of 90%) was obtained in six passes by a monoblock type 20-high rolling mill having a work roll diameter of 70 mm in six passes. In addition, 6
Aging treatment was performed at 200 ° C. for 5 minutes in the middle of the four passes. Then, decarburizing annealing and nitriding annealing were performed, and further, magnesia slurry was applied, followed by high-temperature annealing, and finally, shape correction annealing combined with coating baking, to obtain a product.

The product quality was the same as that of the hot-rolled sheet with a thickness of 1.8 mm, but the highest magnetic properties were the same, but the average properties were improved. In particular, 2 due to unstable finishing temperature of hot rolled sheet
Next time, no fine grains were generated due to unstable recrystallization.

Example 2 A slab of directional silicon steel having the same composition as in Example 1 was heated at a low temperature of 1150 ° C.
A hot-rolled coil having a thickness of 2.3 mm was used. This hot-rolled coil was treated in a continuous annealing / pickling line of a hot-rolled sheet according to the present invention shown in FIG. First, the sheet thickness was reduced to 1.5 mm with a split type 20-high rolling mill having a work roll of 90 mm (thickness reduction rate of 35 mm).
%), Then annealed at 1100 ° C., then pickled, and finally cold rolled to a sheet thickness of 0.71 mm (sheet thickness reduction rate of 53%) using a split type 20-high rolling mill having a work roll diameter of 90 mm.
The mill constant of each rolling mill was 350 tons / mm. After that, a final thickness of 0.15 mm (a thickness reduction rate of 79%) was obtained in four passes by a monoblock type 20-high rolling mill having a work roll diameter of 60 mm. 25 in the first 3 of 4 passes
The aging treatment was performed at 0 ° C. for 5 minutes. Then, after decarburizing annealing, nitriding annealing was performed, and further, magnesia slurry was applied, followed by high-temperature annealing, and finally, shape correction annealing combined with coating baking was performed to obtain a product.

The product quality was the same as that of the hot-rolled sheet having a thickness of 1.5 mm, but the highest magnetic properties were the same, but the average properties were improved. In particular, 2 due to unstable finishing temperature of hot rolled sheet
In this example, no fine grains were generated due to unstable secondary recrystallization. Further, the rolling time in the reverse mill was reduced by 30% as compared with the conventional case. In addition, both ends of the coil of the hot-rolled strip were rolled by the second cold rolling mill, and the off-gauge peculiar to the reverse mill was greatly reduced, and the yield was improved.

Example 3 A slab of directional silicon steel having the same composition as in Example 1 was heated at a low temperature of 1150 ° C.
A hot-rolled coil having a thickness of 2.3 mm was used. This hot-rolled coil was treated in a continuous annealing / pickling line of a hot-rolled sheet according to the present invention shown in FIG. First, the sheet thickness was reduced to 1.5 mm with a split type 20-high rolling mill having a work roll of 90 mm (thickness reduction rate of 35 mm).
%), Then annealed at 1100 ° C., then pickled, and finally, with a split-type 20-high rolling mill having a work roll diameter of 90 mm, a discharge side sheet temperature target of 25 to a sheet thickness of 0.71 mm (sheet thickness reduction rate of 53%).
It was cold rolled at 0 ° C. and wound around a reel at a plate temperature of 230 ° C. and a unit tension of 150 MPa. The mill constant of each rolling mill was 350 tons / mm. afterwards,
After 1 hour, 6 of 4 stands with a work roll diameter of 120 mm
The final thickness was 0.15 mm (79% reduction in thickness) by a Hi-type tandem rolling mill. Then, after decarburizing annealing, nitriding annealing was performed, and further, after applying magnesia slurry, high-temperature annealing was performed,
Finally, shape correction annealing combined with coating baking was performed to obtain a product.

The average quality of the product quality was the same as that of Example 2 (reverse rolling). Further, the rolling time was reduced by more than 85% as compared with the conventional case. In addition, there was no off-gauge peculiar to the reverse mill, and the yield was greatly improved.

[Brief description of the drawings]

FIG. 1 is a quasi-schematic isometric view of a typical prior art processing line for annealing and pickling a hot plate of grain-oriented silicon steel.

FIG. 2 is a quasi-schematic isometric view of an annealing and pickling line for hot-rolled oriented silicon steel according to one embodiment of the present invention (upper and lower tiers are continuous).

FIG. 3 is a semi-schematic isometric view of annealing and pickling for a hot-rolled grain-oriented silicon steel according to another embodiment of the present invention (upper and lower rows are continuous).

FIG. 4 is a semi-schematic isometric view of annealing and pickling for hot-rolled grain-oriented silicon steel according to still another embodiment of the present invention (upper and lower tiers are continuous).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Payoff reel 2 Entry shearing machine 3 Welding machine 4 Entry storage looper 5 Shot blast 6 Cold rolling mill 7 Central storage looper 8 Furnace part 9 Pickling part 10 Bending roller 11 Second cold rolling mill 12 Exit side Storage looper 13 Leveler 14 Outgoing shearing machine 16 Tension reel 17 Outgoing traveling shearing machine 18 Carousel type tension reel 19a, 19b Reel 21a, 21b, 22a, 22b, 23a, 23b, 2
3c, 23d, 27a, 27b, 28a, 28b, 28
c, 28d, 29a, 29b, 29c, 29d Bridle Roll 60 Strip

Claims (17)

[Claims] In a continuous heat treatment equipment for a hot-rolled sheet of grain-oriented silicon steel, a pay-off reel for unwinding a hot-rolled coil, a rolling mill for reducing the thickness of a strip, and the rolling mill A furnace for annealing the strip having a reduced thickness exiting from the furnace, a pickling unit for removing scale of the annealed strip from the furnace, and rewinding of the pickled coil. A continuous heat treatment apparatus for hot-rolled sheets of directional silicon steel, comprising: a tension reel for setting. 2. The continuous heat treatment equipment for hot-rolled sheets according to claim 1, wherein the rolling mill is a split-type 20-high rolling mill, and / or
Alternatively, a continuous heat treatment facility for hot-rolled sheets of directional silicon steel, which is selected from a class consisting of a 12-high rolling mill. 3. The continuous heat treatment equipment for hot-rolled sheets according to claim 1, further comprising a mechanical descaling device disposed upstream of the rolling mill for removing scale on a strip surface generated during hot rolling. A continuous heat treatment facility for hot-rolled sheets of directional silicon steel, characterized in that: 4. The hot rolled directional silicon steel according to claim 3, wherein the mechanical descaling device is selected from a bending roller and / or a shot blast. Continuous heat treatment equipment for plates. 5. The continuous heat treatment equipment for hot-rolled sheets according to claim 1, further comprising a second rolling mill downstream of the pickling section for further reducing the thickness of the strip. A continuous heat treatment facility for hot rolled sheets of directional silicon steel, which is provided. 6. The continuous rolling machine according to claim 5, wherein the second rolling mill is a split die.
Continuous heat treatment equipment for hot-rolled sheets of directional silicon steel, wherein the equipment is selected from a class consisting of a high rolling mill and / or a 12 high rolling mill. 7. The continuous heat treatment equipment for a hot-rolled sheet according to claim 5, wherein the unit tension at the time of rewinding the coil on the tension reel is 100 to 250 MPa.
A continuous heat treatment facility for hot rolled sheets of directional silicon steel, characterized in that: 8. The directional silicon according to claim 5, wherein the temperature of the coil at the tension reel is 150 to 250 ° C. in the continuous heat treatment equipment for a hot rolled sheet according to any one of claims 5 to 7. Continuous heat treatment equipment for hot rolled steel sheets. 9. A method for continuously heat-treating a hot-rolled sheet of grain-oriented silicon steel, comprising: unwinding a hot-rolled coil in one continuous processing line; and reducing a thickness of the strip. A cold rolling step, a step of annealing the strip having a reduced thickness, a step of pickling the annealed strip, and a step of rewinding the pickled coil. A method for continuously heat-treating a hot-rolled sheet of grain-oriented silicon steel. 10. The method for continuously heat-treating a hot-rolled sheet according to claim 9, wherein the cold-rolling step is performed by a split type 20-high rolling mill and / or a 12-high rolling mill. A continuous heat treatment method for a hot-rolled sheet of grain-oriented silicon steel. 11. The method for continuously heat-treating a hot-rolled sheet according to claim 9, further comprising a mechanical descaling step upstream of the cold rolling step in the line. A continuous heat treatment method for hot-rolled silicon steel sheets. 12. The directional silicon steel according to claim 11, wherein the mechanical descaling step is performed by a bending roller and / or a shot blast. Method of continuous heat treatment of hot rolled sheet. 13. The method for continuously heat-treating a hot-rolled sheet according to any one of claims 9 to 12, wherein the thickness of the pickled strip is further reduced downstream of an annealing step in the line. A method for continuously heat-treating a hot-rolled sheet of directional silicon steel, the method including a second cold rolling step for causing a hot rolled sheet of directional silicon steel. 14. The method for continuously heat-treating a hot-rolled sheet according to claim 13, wherein the second cold rolling step includes a split type 20-high rolling mill and / or a 12-high rolling mill. Continuous heat treatment method for hot rolled sheets of directional silicon steel. 15. The hot-rolled sheet of directional silicon steel according to claim 13, wherein the hot-rolled sheet is re-wound at a unit tension of 100 to 250 MPa. Continuous heat treatment method. 16. The continuous heat treatment method for a hot-rolled sheet according to claim 13, wherein the sheet temperature is 150 ° C.
A method for continuously heat-treating a hot-rolled sheet of directional silicon steel, the method comprising rewinding at -250 ° C. 17. The continuous heat treatment method for a hot-rolled sheet of directional silicon steel according to claim 16, wherein the coil is further tandem cold-rolled. .