A short process non-oriented silicon steel foreign matter press-in defect control method

Abstract

The application discloses a short-process non-oriented silicon steel foreign matter press-in defect control method, which is realized based on a thin slab continuous casting and rolling non-oriented silicon steel hot-rolled raw material roll manufacturing process and comprises the following main control stages: a slab thickness wedge, a temperature wedge and a slab centering control stage; a strip steel finishing rolling deviation control stage, which regulates and controls a rigidity difference evaluation value of both sides of a rolling mill and a side guide plate centering deviation of F1-F7 racks of a 7 finishing rolling rack; a strip steel finishing rolling iron oxide scale dust suppression and foreign matter press-in control stage; and a coiling foreign matter press-in control stage; and the like. The control method can significantly reduce the non-oriented silicon steel foreign matter press-in occurrence rate and the hole occurrence rate in a subsequent process and the like, and the operation is relatively convenient, so that the control method is suitable for promotion and application.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel metallurgical production, and particularly relates to a control method for foreign matter pressing defects of short-process non-oriented silicon steel. BACKGROUND

[0002] Low-grade non-oriented silicon steel is mainly used for various small and medium-sized motors, compressors and other equipment. Small and micro motors are mainly produced and processed by automatic high-speed punching and stacking. Not only is the magnetic uniformity of the silicon steel finished plate required, but also the thickness uniformity of the silicon steel finished plate is required. Non-oriented silicon steel produced by thin slab continuous casting and rolling process (short process) has the advantages of uniform performance and good shape, and can also realize the process requirements of low-temperature heating and high-temperature finishing which are difficult to be completed by traditional hot rolling process, so it has developed rapidly. However, the short-process non-oriented silicon steel has a high probability of foreign matter pressing due to its production line characteristics and silicon steel characteristics, and the analysis results of foreign matter composition show that it has multiple sources. The foreign matter pressing in the hot rolling stage of non-oriented silicon steel will form hole defects in the cold rolling process, which has a great impact on product quality.

[0003] The foreign matter pressing of short-process non-oriented silicon steel has a wide range of sources and many influencing factors, so it is difficult to control. Patent CN101134208A provides a strip surface cleaning device before rolling, which removes the foreign matter on the surface of the steel plate before entering the rolling mill by the cleaning device composed of nozzles and brush rollers, thereby minimizing the generation of foreign matter pressing defects caused by the rolling of the strip. Patent CN102658292A provides a non-oriented electrical steel processing method, which reduces the holes in the non-oriented electrical steel strip caused by foreign matter pressing by adjusting the control mode of the side guide plate operation side of the pinch roll. Patent CN106623436A discloses a rolling mill device for preventing foreign matter pressing, which comprises a frame of a rolling mill and a nozzle and a water pipe connected thereto, and removes the foreign matter on the surface of the strip by spraying. Patent CN108114994A relates to an equipment and method for reducing iron scale pressing during the production of strip steel by a hot continuous rolling mill, which reduces the pressing of foreign matter on the surface of the strip by blocking and blowing, eliminates rust spots by increasing the anti-corrosion function, further reduces the iron scale pressing defects, and improves the quality of the strip steel product. Patent CN207642000U discloses a device for preventing foreign matter pressing of hot-rolled strip steel, which prevents foreign matter from falling onto the surface of the strip by setting a baffle above the strip, thereby effectively avoiding the defects caused by foreign matter pressing. The above-mentioned solutions only provide common measures for foreign matter pressing of conventional hot rolling finishing mill, and do not consider the foreign matter pressing caused by the characteristics of the steel grade. SUMMARY

[0004] The main purpose of the present application is to solve the problems and deficiencies of the prior art, and provide a short process non-oriented silicon steel foreign matter pressing defect control method, which can effectively reduce the occurrence rate of non-oriented silicon steel foreign matter pressing defects.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0006] A short process non-oriented silicon steel foreign matter pressing defect control method, which is realized based on a thin slab continuous casting and rolling non-oriented silicon steel hot rolling raw material coil manufacturing process, mainly includes the following processes: molten steel smelting, thin slab continuous casting, slab descaling before the furnace, slab tunnel furnace heating, descaling before finishing rolling, 7-stand finishing rolling, laminar cooling, and coiling, and includes the following main control stages:

[0007] Stage (1): slab thickness wedge, temperature wedge and slab centering control stage;

[0008] Stage (2): strip finishing rolling deviation control stage;

[0009] Stage (3): strip finishing rolling iron oxide scale dust suppression and foreign matter pressing control stage;

[0010] Stage (4): coiling foreign matter pressing control stage;

[0011] In the stage (1), the slab thickness wedge value |Hw|≤0.5mm is obtained by controlling the precision of the continuous casting fan-shaped segment foot roller and the uniformity of the continuous casting slab cooling; the slab temperature wedge value |Tw|≤15℃ is obtained by controlling the temperature uniformity of the slab width direction in the soaking furnace; the centering deviation |Δ C1 | of the slab out of the furnace and the rolling center line is ≤20mm by controlling the height difference of the adjacent roller rings in the soaking furnace ≤3mm and the elevation deviation of the furnace roller ≤3mm;

[0012] Wherein, the slab thickness wedge value Hw is the thickness difference value between the DS side and the OS side of the slab width direction, Hw=H OS -H DS ; the slab temperature wedge value Tw is the temperature difference value between the DS side and the OS side of the slab width direction, Tw=T OS -T DS ;

[0013] In the stage (2), the stiffness of both sides of each stand of finishing rolling is monitored, and the rolling mill stiffness difference evaluation value ΔM=2(M DS -M OS ) / (M DS +M OS )×100%, wherein M DS , M OSThese refer to the drive-side stiffness and operating-side stiffness of the finishing mill stand, respectively; by controlling the wear of the stand components and the gap between the stands, the mill stiffness difference evaluation value |ΔM| is kept ≤4%, and the centering deviation of the side guide plates of the finishing mill F1~F7 stands is controlled |Δ C2 ≤5mm;

[0014] In stage (3), the slab exit temperature is controlled at 1100-1140℃, the descaling pressure at the finishing mill inlet is 300-380 bar, the finishing mill inlet temperature FET is 1000-1040℃, and the finishing mill exit temperature FDT is 860-900℃.

[0015] In stage (3), the anti-stripping water, dust suppression water, water spray on the stand exit side, and bidirectional side spray on the stand inlet guide plate are controlled to be activated, and the inter-stand cooling water is controlled to have a flow rate of 120-150 m³ / h. 3 / h; The opening sequence of anti-stripping water, finishing rolling dust suppression water, and inter-stand cooling water is shown in the table below. The opening sequence value is the distance between the slab head and the soaking furnace door.

[0016] Table 1 Startup Timing (m)

[0017] F1 F2 F3 F4 F5 F6 F7 Anti-stripping water 14.1～16.1 21～23 29.6～31.6 35.1～37.1 Finishing mill dust suppression water 43～45 49～51 57～59 Inter-stand cooling water 15～17m 20.5～22.5m 26～28m

[0018] In stage (3), the water jet medium for dust suppression in the finishing mill is a mixture of water and air, and the nozzle is an air atomizing nozzle. The air pressure is 320-360 kPa and the flow rate is 140-160 lpm. The water supply pressure is 260-280 kPa and the flow rate is 1.6-1.8 lpm. The outlet diameter of the water-air mixing nozzle is d = 1.8-2.2 mm, and the diameter of the generated droplets is 30-50 μm.

[0019] In stage (4), the clamping pressure of the winding side guide plate is controlled to be P. SG =(P 基准 )×(580 / winding temperature)+P 修正 , making P SG = 1.5~2.5KN; when the strip thickness is 2.5~4.1mm, P 基准 =5.3~6.3KN.

[0020] The thickness range of 2.5 to 4.1 mm is the production range of silicon steel thickness for short-process production lines. Due to the limitations of the comprehensive performance requirements of silicon steel in subsequent processes, a thicker or thinner thickness is not of practical significance.

[0021] In stage (4), bidirectional side spray water is used in front of the pinch roller to flush away any foreign objects that may be generated on the plate surface. The side spray water pressure is 15 to 20 bar.

[0022] The main chemical components and their mass percentages in the short-process non-oriented silicon steel of this invention include: C≤0.003%, Si 0.8~2.0%, Mn 0.10~1.0%, S≤0.005%, P≤0.030%, N≤0.004%, and Als0.10~0.40%.

[0023] The principle of this invention is as follows:

[0024] In stage (1) of this invention, the thickness wedge value |Hw| of the slab is controlled to be ≤0.5mm and the temperature wedge value |Tw| in the width direction of the slab is controlled to be ≤15℃, and the centering deviation |Δ| between the slab exiting the furnace and the rolling centerline is controlled. C1 |≤20mm: When the slab at the rolling inlet has a certain thickness wedge or temperature wedge, uneven compression will occur on both sides of the strip in the roll gap during rolling (operating side OS, drive side DS), resulting in inconsistent elongation on both sides. The side with greater compression will elongate more than the other side, and the strip will exhibit lateral bending, also known as "sickle bending". Figure 1 As shown in (a) and 1(b), when the center deviation between the slab exiting the furnace and the rolling center line is greater than 20mm, uneven pressing will also occur on both sides, resulting in a sickle bend. This can easily scrape the side guide plate, causing the nodules on the side guide plate to fall onto the plate surface and form foreign objects pressed in under the action of the rolling rolls.

[0025] In stage (2), the wear of the stand and the clearance between the stands are controlled to ensure that the stiffness evaluation value |ΔM| ≤ 4%, while the centering deviation of the side guide plates of the finishing mill F1 to F7 stands is controlled |Δ C2 ≤5mm: When the stiffness deviation on both sides of the rolling mill is large, the elastic deformation of the two sides of the mill and its components is different during rolling. This causes the axes of the two rolls to no longer be parallel, resulting in different reduction rates on both sides of the strip and differences in the exit thickness of the strip. Consequently, the strip may deviate and exhibit camber. Figure 1 As shown in (c); control the centering deviation |Δ of the F1~F7 finishing rolling side guide plates. C2 |≤5mm, also to control the deviation of the rolled piece, the principle is similar to the above situation.

[0026] In stage (3), the slab exit temperature is controlled at 1100-1140℃, the descaling pressure at the finishing mill inlet is 300-380 bar, the finishing mill inlet temperature FET = 1000-1040℃, and the finishing mill exit temperature FDT = 860-900℃. Anti-stripping water is added and a large flow of interstand cooling water is used. The higher the surface temperature of the strip, the thicker the iron oxide scale layer on its surface. In addition, due to the high Si content of non-oriented silicon steel, the oxide layer and the matrix interface will form a Fe2SiO4 layer to hinder the outward diffusion of Fe ions. As a result, the proportion of high-valence oxides Fe2O3 and Fe3O4 will be higher, and the proportion of high-valence oxide Fe2O3 increases with the increase of temperature. The Fe2O3 phase also has poor plasticity at high temperatures (e.g.,Figure 3 As shown, it is easy for the iron oxide scale to break and form dust. By controlling the furnace temperature and adding surface cooling water to reduce the surface temperature of the non-oriented silicon steel, the thickness of the oxide layer formed on the surface of the strip during rolling is reduced, and the proportion of Fe2O3 phase in the surface oxide layer is reduced, thereby controlling the amount of dust generated after the iron oxide scale breaks.

[0027] In stage (3), the opening of the finishing mill anti-stripping water, finishing mill dust suppression water, stand exit side spray water, and stand inlet guide plate bidirectional side spray water is controlled: the dust suppression water suppresses the iron oxide scale dust at the roll gap and prevents it from accumulating on the equipment, and suppresses the black water generated from flowing into the lower stand along the slab; the stand exit side spray water and the stand inlet guide plate bidirectional side spray water prevent the slag-laden black water that has not been removed by the dust suppression water from entering the lower stand roll gap; at the same time, the opening sequence of the anti-stripping water, finishing mill dust suppression water, and inter-stand cooling water is further controlled. The distance between the soaking furnace door and the F1 stand roll gap is 13.6m and the stand roll gap spacing is 5.5m. Therefore, the opening sequence is a period of time after the roll gap bites the steel, which reduces the temperature drop of the slab head and avoids the severe impact of the stand when the low-temperature slab head bites the steel, causing the dust accumulated on the stand arch to fall onto the plate surface; the finishing mill anti-stripping water, finishing mill dust suppression water, stand exit side spray water, stand inlet guide plate bidirectional side spray water, and inter-stand cooling water are arranged in the finishing mill stand as follows. Figure 3 As shown.

[0028] In stage (3), the water jet medium for dust suppression in the finishing mill is a mixture of water and air, and the nozzle is an air atomizing nozzle. The air pressure is 320-360 kPa and the flow rate is 140-160 lpm. The water supply pressure is 260-280 kPa and the flow rate is 1.6-1.8 lpm. The outlet diameter of the water-air mixing nozzle is d = 1.8-2.2 mm. The generated droplet diameter is 30-50 μm. During the hot rolling process, iron oxide scale dust will be generated in the strip steel. Depending on the steel composition, temperature and rolling speed, the amount and characteristics of iron oxide scale dust are different. Due to the high Si content, silicon steel will form an iron oxide scale structure mainly composed of high-valence oxides Fe2O3 and Fe3O4 on its surface. Fe2O3 and Fe3O4 have poor plasticity at high temperatures and are prone to breakage. Due to the characteristics of high-temperature iron oxide scale, a large amount of iron oxide scale dust is generated, with an average particle size of 30μm. Typically, the most severe dust generation occurs in the last three to four stands of the finishing mill. The high strip speed during rolling creates a "fan effect," blowing the oxide dust across the mill stands and covering almost all equipment. When the mill is subjected to impact or vibration, the dust covering the mill equipment surface easily falls onto the strip surface, forming a build-up. The droplets generated from the nozzle must be similar in size to or slightly larger than the iron oxide scale dust particles to collide with and completely capture them. If the droplets from the nozzle are too large, the iron oxide scale dust will simply escape with the airflow around the droplets; if the droplets are too small, the iron oxide scale dust will bounce off or bypass the spray droplets.Figure 4 As shown, under reasonable pressure and nozzle diameter design conditions, the present invention can effectively control dust by controlling droplets to a range of 30-50 μm through proper mixing of air and water.

[0029] In stage (4), the clamping pressure of the winding side guide plate is controlled to be P. SG =(P 基准 )×(580 / winding temperature)+P 修正 , making P SG = 1.5~2.5KN; when the strip thickness is 2.5~4.1mm, P 基准 =5.3~6.3KN; Micro-pressure clamping is achieved by modifying and controlling the side guide plate pressure, preventing burrs on the strip edge and nodules on the side guide plate from falling off due to the high pressure of the side guide plate and forming foreign objects pressed in under the pressure of the pinch rollers, as shown in the attached... Figure 5 As shown.

[0030] In stage (4), the number of side sprays on the front of the pinch roll is increased (from one side spray in one direction to two side sprays in two directions) and the pressure is increased to enhance the cleaning effect of the side sprays on the strip surface and further prevent foreign objects from being pressed into the pinch roll, as shown in the attached figure. Figure 5 As shown.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) By controlling the thickness wedge, temperature wedge and centering of the billet, the stiffness deviation on both sides of the rolling mill and the centering deviation of the side guide plate, the asymmetric rolling of the finished strip steel is prevented from forming a sickle bend that scratches the side guide plate. The clamping pressure of the coiling side guide plate is controlled during coiling to reduce the source of nodule-like foreign matter from the source.

[0033] (2) By controlling the temperature of the slab and finishing mill, and by adding water to the finishing mill (descaling water at the finishing mill inlet, anti-stripping water and cooling water between stands), the surface temperature of non-oriented silicon steel is reduced, thereby controlling the thickness and proportion of the oxide layer and controlling the amount of iron oxide scale dust generated; at the same time, based on the control of the droplet size of the dust suppression water, the iron oxide scale dust capture rate is increased.

[0034] (3) By forming a multi-point side spraying layout with side spraying at the frame outlet, bidirectional side spraying at the frame inlet guide plate, and bidirectional side spraying in front of the pinch roller, the probability of foreign matter being pressed in is further reduced.

[0035] (4) The present invention integrates the above-mentioned various improvement methods, which can significantly reduce the occurrence rate of foreign matter indentation in non-oriented silicon steel and the occurrence rate of voids in subsequent processes, and is suitable for widespread application. Attached Figure Description

[0036] Figure 1The diagram illustrates the formation mechanism of the sickle bend in the non-oriented silicon steel strip described in this invention: (a) caused by the wedge shape of the slab thickness; (b) caused by the temperature wedge shape; (c) caused by the difference in stiffness on both sides of the rolling mill.

[0037] Figure 2 A comparison diagram of the thermoplasticity of various iron oxide scale phases on the surface of strip steel at high temperature;

[0038] Figure 3 A schematic diagram showing the distribution of cooling water between the finishing mill stands for the mill's anti-stripping water, dust suppression water, water spraying on the stand exit side, and bidirectional side spraying on the stand inlet guide plate.

[0039] Figure 4 A schematic diagram of a dust removal mechanism based on the control of the diameter of water droplets in the dust-pressing process;

[0040] Figure 5 This is a schematic diagram of bidirectional side spray cleaning of detached material before winding. Detailed Implementation

[0041] The present invention will be further explained below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0042] The production of non-oriented silicon steel based on the short process mainly includes the following steps: molten steel smelting → thin slab continuous casting → slab descaling before furnace → slab tunnel furnace heating → descaling before finishing rolling → 7-stand finishing rolling → laminar flow cooling → coiling.

[0043] The smelting composition of the non-oriented silicon steel includes: C≤0.003%, Si 0.8~2.0%, Mn 0.10~1.0%, S≤0.005%, P≤0.030%, N≤0.004%, and Als 0.10~0.40%.

[0044] The method for controlling foreign object indentation defects in short-process non-oriented silicon steel according to the present invention includes the following main control stages:

[0045] Stage (1): Slab thickness wedge, temperature wedge and slab centering control stage;

[0046] Stage (2): Strip steel finishing rolling deviation control stage;

[0047] Stage (3): Dust suppression and foreign matter intrusion control of iron oxide scale in strip finishing rolling;

[0048] Stage (4): Foreign object entrainment and compression control stage;

[0049] In stage (1), the wedge value of slab thickness |Hw| is ≤0.5mm by controlling the accuracy of the fan-shaped section foot rolls in the thin slab continuous casting process and the cooling uniformity of the continuous casting slab; the temperature uniformity in the width direction of the slab in the soaking furnace is controlled so that the wedge value of slab temperature |Tw| is ≤15℃; the height difference between adjacent roll rings in the roller-bottom tunnel soaking furnace is ≤3mm and the elevation deviation of the furnace rolls is ≤3mm so that the centering deviation value |Δ| between the slab exiting the furnace and the rolling centerline is ≤3mm. C1 |≤20mm; Composition system, number of slabs, slab thickness wedge |Hw|, slab temperature wedge |Tw|, centering deviation between slab and rolling centerline |Δ C1 As shown in Table 1.

[0050] Table 1. Slabs |Hw|, |Tw|, |Δ in Examples and Comparative Examples C1 | value

[0051]

[0052]

[0053] In stage (2), the stiffness of both sides of each stand in the finishing mill is monitored, and the evaluation value of the stiffness difference between the two sides of the mill is ΔM = 2(M DS -M OS ) / (M DS +M OS ×100%, by controlling the wear of the stand components and the gap between the stands, the stiffness difference between the two sides of the mill is kept to be ≤4%, and the centering deviation of the side guide plates of the finishing mill F1~F7 stands is controlled to be ≤4%. C2 |≤5mm; Evaluation values ​​of the stiffness difference between the two sides of the rolling mill in the examples and comparative examples |ΔM| and the centering deviation of the finishing mill side guide plate |Δ C2 As shown in Table 2.

[0054] Table 2. Values ​​of |ΔM| and centering deviation of the precision-rolled side guide plate in the examples and comparative examples. C2 |

[0055]

[0056] In stage (3), the slab exit temperature is controlled at 1100-1140℃, the descaling pressure at the finishing mill inlet is 300-380 bar, the finishing mill inlet temperature FET = 1000-1040℃, and the finishing mill exit temperature FDT = 860-900℃; the temperature and descaling process parameters of the examples and comparative examples are shown in Table 3.

[0057] Table 3 Temperature and descaling process parameters for the examples and comparative examples

[0058]

[0059] In stage (3), the anti-stripping water, dust suppression water, water spray at the stand exit side, bidirectional side water spray at the stand inlet guide plate, and inter-stand cooling water are controlled to be activated, and the flow rate of the inter-stand cooling water is controlled to be 120-150 m³ / h. 3 Table 4 compares the operating states of the finishing mill water systems in the examples and comparative examples. The operating sequence of the anti-stripping water, finishing mill dust suppression water, and inter-stand cooling water in the examples is shown in Table 5 below.

[0060] Table 4 Comparison of the operating states of the finishing water system in the embodiments and comparative examples

[0061]

[0062]

[0063] Note: The introduction of cooling water between the stands and the large flow rate reduce the surface temperature of the non-oriented silicon steel, thereby reducing the thickness of the oxide layer formed on the surface of the strip during rolling and reducing the proportion of Fe2O3 phase in the surface oxide layer, thus controlling the amount of dust generated after the iron oxide scale is broken.

[0064] Table 5 shows the activation sequence of anti-stripping water, finishing mill dust suppression water, and interstand cooling water in the embodiments.

[0065] F1 F2 F3 F4 F5 F6 F7 Anti-stripping water 15.1m 22m 30.6m 36.1m Finishing mill dust suppression water 44m 50m 58m Inter-stand cooling water 16m 21.5m 27m

[0066] In stage (3), the water jet medium for the fine rolling dust suppression in the embodiment uses a mixture of water and air, and the nozzle is an air atomizing nozzle. The air pressure is 320-360 kPa and the flow rate is 140-160 lpm. The water supply pressure is 260-280 kPa and the flow rate is 1.6-1.8 lpm. The outlet diameter of the water-air mixing nozzle is d = 1.8-2.2 mm. The generated droplet diameter is 30-50 μm.

[0067] In stage (4), the clamping pressure of the take-up side guide plate is controlled to be P. SG =(P 基准 )×(580 / winding temperature)+P 修正 , making P SG = 2KN; when the strip thickness is 2.5~4.1mm, P 基准 =5.8KN;

[0068] In stage (4), bidirectional side spray water is used in front of the pinch roller to flush away any foreign matter that may be generated on the plate surface. The side spray water pressure is 15 to 20 bar.

[0069] Table 6 Comparison of Side Guide Plate Pressure and Side Spray Process between Examples and Comparative Examples

[0070]

[0071] Table 7 shows the Fe2O3 ratio in the iron oxide scale phase, the dust removal efficiency of finishing rolling, the foreign matter indentation rate, and the porosity of subsequent processes obtained under different processes in each embodiment and comparative example. It can be seen that the Fe2O3 ratio in the high-temperature iron oxide scale phase of the strip is reduced under the process of the embodiments, thus reducing the amount of dust. Simultaneously, based on the control of the dust-pressing water droplet particle size, the dust removal efficiency of finishing rolling is improved, and the foreign matter indentation rate and the porosity of subsequent processes are significantly reduced compared to the comparative example.

[0072] Table 7 Comparison of the effects of the examples and comparative examples.

[0073]

[0074]

[0075] This invention is not limited to the embodiments described above. Those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A method for controlling foreign object press-in defects in short-process non-oriented silicon steel, characterized in that, This control method is based on the manufacturing process of hot-rolled non-oriented silicon steel raw material coils through continuous casting and rolling of thin slabs, and mainly includes the following steps: molten steel smelting → continuous casting of thin slabs → descaling of slabs before furnace → slab heating in tunnel furnace → descaling before finishing rolling → 7-stand finishing rolling → laminar flow cooling → coiling; it also includes the following main control stages: Stage (1): Slab thickness wedge, temperature wedge and slab centering control stage; Stage (2): Strip finishing mill deviation control stage, adjusting and controlling the stiffness difference evaluation value on both sides of the mill and the centering deviation of the side guide plates of the 7 finishing mill stands F1 to F7; Phase (3): Suppression of iron oxide scale dust and control of foreign matter intrusion in strip finishing rolling, specifically including: Adjust the slab exit temperature, the descaling pressure at the finishing mill inlet, the finishing mill inlet temperature FET, and the finishing mill exit temperature FDT; Turn on the finishing mill anti-stripping water, finishing mill dust suppression water, stand outlet side spray water, stand inlet guide plate bidirectional side spray water, and stand interstand cooling water; and adjust the cooling water flow rate between finishing mill stands and the finishing mill dust suppression water spray conditions. Stage (4): Foreign object pressing control stage; control the clamping pressure of the winding side guide plate, and use bidirectional side spray water to flush the plate surface in front of the clamping roller.

2. The control method according to claim 1, characterized in that, The main chemical components and their mass percentages in the short-process non-oriented silicon steel are as follows: C≤0.003%, Si 0.8~2.0%, Mn 0.10~1.0%, S≤0.005%, P≤0.030%, N≤0.004%, Als 0.10~0.40%.

3. The control method according to claim 1, characterized in that, In stage (1), the slab thickness wedge |Hw| is controlled to be ≤0.5mm; the slab temperature wedge |Tw| is controlled to be ≤15℃; and the alignment deviation between the slab exiting the furnace and the rolling centerline |Δ C1 ≤20mm.

4. The control method according to claim 1, characterized in that, Evaluation value of stiffness difference between the two sides of the rolling mill: ΔM = 2(M DS -M OS ) / (M DS +M OS )×100%, where M DS M OS These refer to the drive-side stiffness and operating-side stiffness of the finishing mill stand, respectively.

5. The control method according to claim 1, characterized in that, In stage (2), the stiffness difference evaluation value |ΔM| on both sides of the rolling mill is controlled to be ≤4%, and the centering deviation of the guide plates on the side of the finishing mill F1~F7 stands is controlled to be ≤4%. C2 ≤5mm.

6. The control method according to claim 1, characterized in that, In stage (3), the slab exit temperature is controlled at 1100-1140℃, the descaling pressure at the finishing mill inlet is 300-380 bar, the finishing mill inlet temperature FET is 1000-1040℃, and the finishing mill exit temperature FDT is 860-900℃.

7. The control method according to claim 1, characterized in that, Turn on the finishing mill anti-stripping water, finishing mill dust suppression water, stand outlet side spray water, bidirectional side spray water at the stand inlet guide plate, and inter-stand cooling water; control the inter-stand cooling water flow rate to 120-150 m³ / h. 3 / h, adjust the opening sequence values ​​of anti-stripping water, finishing mill dust suppression water, and inter-stand cooling water, where the opening sequence value is the distance between the slab or strip head and the soaking furnace door. Specific control requirements include: Anti-stripping water activation sequence: F1 frame 14.1~16.1m, F2 frame 21~23m, F3 frame 29.6~31.6m, F4 frame 35.1~37.1m; Dust suppression water activation sequence for finishing mill: F5 stand 43-45m, F6 stand 49-51m, F7 stand 57-59m; Cooling water turn-on sequence between racks: F1 rack 15-17m, F2 rack 20.5-22.5m, F3 rack 26-28m.

8. The control method according to claim 1, characterized in that, In stage (3), the water jet medium for dust suppression in the finishing mill is a mixture of water and air, and the nozzle is an air atomizing nozzle. The air pressure is 320-360 kPa and the flow rate is 140-160 lpm. The water supply pressure is 260-280 kPa and the flow rate is 1.6-1.8 lpm. The outlet diameter of the water-air mixing nozzle is d = 1.8-2.2 mm, and the diameter of the generated droplets is 30-50 μm.

9. The control method according to claim 1, characterized in that, In stage (4), the clamping pressure of the winding side guide plate is controlled to be P. SG =(P 基准 )×(580 / winding temperature)+P 修正 , making P SG = 1.5~2.5KN; when the strip thickness is 2.5~4.1mm, P 基准 =5.3~6.3KN.

10. The control method according to claim 1, characterized in that, In stage (4), bidirectional side spray water is used to scour the plate surface in front of the pinch roller, with a side spray water pressure of 15 to 20 bar.

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