Method for precisely controlling rough rolling outlet temperature of ferrite steel strip

Abstract

This invention relates to a method for precise control of the exit temperature of IF steel strip roughing mill, belonging to the technical field of control methods specifically applicable to metal rolling mills. The method sets up an oscillation zone between the R1 and R2 mills in an existing rolling production line. It uses the existing temperature calculation model of the rolling production line to read the inlet temperature of the strip in the oscillation zone of the 6th pass of R2, iteratively calculating the oscillation time, the temperature drop of the strip from the inlet of the oscillation zone to the exit of R2, and the exit temperature T1 of the strip at R2. Simultaneously, it corrects the roughing mill corrected target exit temperature T based on the deviation between the previously measured strip temperature and the specified roughing mill target exit temperature. By gradually bringing T1 closer to T, T1 more accurately reaches or approaches the production requirement of the roughing mill R2 target exit temperature T0. The oscillation time calculated when it is closest to T is used as the actual oscillation time and the oscillation is executed, thereby controlling the roughing mill exit temperature to reach the production-specified target exit temperature.

Description

Technical Field

[0001] This invention relates to a method for ensuring that the roughing mill exit temperature meets production requirements during IF steel rib rolling, and belongs to the technical field of control methods specifically applicable to metal rolling mills. Background Technology

[0002] IF steel slurry rolling process as follows Figure 1 As shown: The strip steel passes through the furnace front roller table, descaling box, and R1 mill for rolling, and then undergoes reversible rolling on the R2 reversible mill. After reversible rolling, it enters the hot coil box for coiling. After coiling in the hot coil box, it is uncoiled only after the hot coil box scraper is in place. After uncoiling, it enters the finishing mill for rolling. Thermometers are generally placed at the entrance and exit of the R2 mill and the entrance of the finishing mill. In the area from the heating furnace to the exit of the R1 mill (entrance of the R2 mill), due to environmental factors and iron oxide scale on the surface of the strip steel, accurate measurement is not possible, therefore thermometers are not installed. The rolling temperature requirements for IF steel strip are as follows: the furnace exit temperature is about 1120°C, the finishing mill inlet temperature is ≤840°C, and after roughing, the strip temperature drops by 280°C before the finishing mill inlet to achieve the required inlet temperature of ≤840°C. Therefore, the target exit temperature of the roughing mill must be controlled at ≤860°C (the temperature drop between the pyrometer at the R2 exit of the roughing mill and the pyrometer at the finishing mill inlet is usually about 20°C).

[0003] For rolling lines without water cooling equipment, to achieve significant temperature reduction, a swing zone is typically added between the R1 and R2 mills. The roughing mill rolling pattern is set to 1+7, with the last pass skipped (i.e., 1 pass in R1, 6 passes in R2, and the 7th pass in R2 skipped). After the strip has rolled 7 passes, air cooling and thermal radiation are used to achieve swing cooling in the swing zone. During swinging, the operator observes the thermometer at the R2 inlet or outlet and manually stops the swing once the required temperature is reached. However, this control method cannot reliably guarantee that the actual roughing mill exit temperature reaches the target roughing mill exit temperature.

[0004] A Chinese patent with publication number CN111250545A discloses a control system and method for reducing the over-thickness rate of oscillating steel coils. This system and method address the problem of excessive thickness at the finishing mill exit when the strip oscillates. The solution is to recalculate and adjust the finishing mill inlet temperature based on the oscillation time. However, this adjustment of the finishing mill inlet temperature is not intended to make the actual finishing mill inlet temperature close to the target finishing mill inlet temperature. It only aims to prevent the finishing mill exit from being over-thick based on the oscillation time, and cannot guarantee that the roughing mill exit temperature meets the standard.

[0005] Chinese patent CN103990653A discloses a method for ensuring the accuracy of the finishing mill inlet temperature. This method calculates the roughing mill outlet temperature T2 based on the furnace exit temperature T0, and then calculates the roughing mill outlet temperature T1 based on FTO and speed. According to the method's specification, with an iteration cycle of 300ms and an upper limit of 180 iterations, the maximum oscillation time is 54 seconds and the maximum temperature drop is 82°C. However, the general requirement for the overall temperature drop in roughing milling is around 130°C, which fails to meet the roughing mill outlet temperature requirements for IF steel production. Summary of the Invention

[0006] The technical problem to be solved by this invention is: how to accurately achieve the target exit temperature of the roughing mill in the rolling of IF steel basalt strip.

[0007] The technical solution proposed by this invention to solve the above-mentioned technical problems is: a method for precise control of the exit temperature of IF steel rib strip roughing mill, involving two roughing mill stations R1 and R2 in the rolling production line and the existing temperature calculation model of the rolling production line, and performing the following steps:

[0008] S1. Set the roughing mode of one pass for R1 and seven passes for R2, and let the seventh pass of R2 pass empty. Set the swing zone between the R1 mill and the R2 mill, and enter the swing zone after the R2 mill completes the sixth pass to start calculating the swing time and swinging.

[0009] S2. Read the temperature calculation model and calculate the inlet temperature T of the strip in the swing zone in the sixth pass of R2. 入口 ;

[0010] S3. Calculate the exit temperature T1 of the strip at R2 using the following formula (1) iteratively.

[0011] T1 = T_inlet - T_temperature drop (1),

[0012] In equation (1), T1 is the outlet temperature of the strip at R2 calculated iteratively, and T_temperature drop is the temperature drop of the strip from the inlet of the pre-swinging zone of R2 to the outlet of R2, calculated according to equation (2).

[0013] Temperature drop T = W * t1(2),

[0014] In equation (2), W is the temperature drop per unit time of the strip from the inlet to the outlet of R2 in the swing zone before R2 calculated by the temperature calculation model, and t1 is the swing time calculated in the current iteration after iteration. The iteration calculation of t1 is expressed as follows: equation (3).

[0015] t1=t10+(T10-T)*G, (3),

[0016] In equation (3), T10 is the strip exit temperature at R2 calculated in the previous iteration, G is a coefficient in seconds / ℃, t10 is the oscillation time calculated in the previous iteration, and T is the roughing mill correction target exit temperature corrected based on the measured roughing mill exit temperature, calculated according to equation (4).

[0017] T = T0 - Tv (4),

[0018] In equation (4), T0 is the target exit temperature of the roughing mill R2 specified in the production process, and Tv is the correction value of the target exit temperature of the roughing mill for the current rolled strip. The calculation of Tv is expressed as in equation (5).

[0019] Tv=Tv0+dR*Ga (5),

[0020] In equation (5), Tv0 is the correction value of the target exit temperature of the previous rolled strip, Ga is a constant, dR is the deviation of the exit temperature of the previous rolled strip, and dR = the measured exit temperature of the previous rolled strip - the target exit temperature of the previous rolled strip T0.

[0021] The temperature drop and T1 are calculated iteratively starting from the initial value according to the oscillation time;

[0022] S4. Compare T1 calculated in each iteration with T.

[0023] If |T1-T| ≥ 1, then repeat step S3;

[0024] If |T1-T| < 1, then stop the calculation, output the swing time t1 calculated in the current iteration as the swing time of the strip entering the swing zone, and execute the swing.

[0025] Furthermore, the Tv iterative calculation in step S3 is expressed by the following equation (6):

[0026] Tv=Tv0+dR*Ga+dF*(1-Ga) (6),

[0027] In formula (6), dF is the temperature deviation of the previous strip steel finishing entry. dF = the measured temperature of the previous strip steel finishing entry - the target temperature of the finishing entry. The target temperature of the finishing entry is required by the rolling production line.

[0028] Furthermore, as is known, W in equation (2) is calculated by the temperature calculation model according to equation (7).

[0029]

[0030] In equation (7), ρ is the density coefficient of the strip, Cp is the specific heat coefficient of the strip, V is the volume of the strip, and Q is the heat lost by radiation from the strip, calculated by the temperature calculation model according to equation (5).

[0031] Q=ε*A*σ(T 环境 -T 入口 (8)

[0032] In equation (8), ε is the thermal emissivity coefficient, A is the emissivity coefficient, σ is the Stefan-Boltzmann constant, and T 环境 It refers to the ambient temperature.

[0033] Furthermore, G in equation (3) is 0.05-0.15, Ga in equation (5) is 0.7, and the initial value of the oscillation time is 0-180 seconds.

[0034] The beneficial effects of this invention are as follows: By linking the temperature drop T calculated at the R2 exit of the strip with the set oscillation time t1, the calculated exit temperature T1 of the strip at R2 is correlated with the oscillation time t1. Simultaneously, the roughing mill corrected target exit temperature T is obtained by correcting the deviation between the previously measured strip temperature and the specified roughing mill target exit temperature. The oscillation time and the corrected value are iteratively calculated from the initial value, and T1 and T are compared. When the difference between the calculated T1 and T is large, the calculation of t1, T (temperature drop), and T1 continues iteratively. When the calculated T1 is close to T, the calculation stops, and the currently calculated oscillation time is output as the time for the strip to enter oscillation, and oscillation is executed. Therefore, in the rolling of IF steel rib strip, the strip can oscillate between R1 and R2 according to the oscillation time close to the corrected roughing mill exit target temperature T. This allows for more precise control of the roughing mill exit (R2 exit) temperature to reach the production-specified roughing mill exit target temperature T0. Attached Figure Description

[0035] Figure 1 This is a layout diagram of the rolling production line equipment involved in the method for precise control of the exit temperature of IF steel rib strip roughing mill in this invention. Detailed Implementation

[0036] Example 1

[0037] This embodiment describes a method for precise control of the exit temperature of IF steel ribbed strip roughing mill, involving the Meigang 1422 hot rolling production line. The specifications of a certain IF steel ribbed strip being rolled are shown in Table 1 below. The rolling production line has two roughing mill stations, R1 and R2, and an existing temperature calculation model for the rolling production line is available.

[0038] Table 1

[0039]

[0040]

[0041] The specific steps are as follows:

[0042] S1. Set the roughing mode to one pass for R1 and seven passes for R2, with the last pass of R2 (the seventh pass) skipped. Set the oscillation interval between the R1 and R2 mills, and begin calculating the oscillation time and executing the oscillation after the R2 mill completes its sixth pass, as shown below. Figure 1 As shown.

[0043] S2. Read the existing temperature calculation model of the rolling production line and calculate the inlet temperature T of the strip in the swinging region in the sixth pass of R2. 入口 It is 1040℃;

[0044] S3. Calculate the exit temperature T1 of the strip at R2 using the following formula (1) iteratively.

[0045] T1 = T_inlet - T_temperature drop (1),

[0046] In equation (1), T1 is the exit temperature of the strip at R2 calculated iteratively, and T_temperature drop is the temperature drop of the strip from the inlet to the outlet of the pre-R2 swing zone.

[0047] Temperature drop T = W * t1 (2),

[0048] In equation (2), W is the temperature drop of the strip from the inlet to the outlet of R2 in a fixed unit time, calculated by the existing temperature calculation model of the rolling production line. t1 is the oscillation time calculated in the current iteration, and the iterative calculation of t1 is expressed as in equation (3).

[0049] t1=t10+(T10-T)*G, (3),

[0050] In equation (3), T10 is the strip exit temperature at R2 calculated in the previous iteration, G is a coefficient in seconds / ℃, generally taken as 0.1, t10 is the oscillation time calculated in the previous iteration, and T is the roughing mill correction target exit temperature corrected based on the measured roughing mill exit temperature, calculated according to the following equation (4).

[0051] T = T0 - Tv (4),

[0052] In equation (4), T0 is the target exit temperature of the roughing mill R2 specified in the production process, and Tv is the correction value of the target exit temperature of the current strip roughing mill. The calculation of Tv is expressed as in equation (5).

[0053] Tv=Tv0+dR*Ga (5),

[0054] In equation (5), Tv0 is the correction value of the target exit temperature of the previous rolled strip, Ga is a constant, generally taken as 0.7; dR is the deviation of the exit temperature of the previous rolled strip, dR = measured exit temperature of the previous rolled strip - target exit temperature of the previous rolled strip T0.

[0055] As is known, the existing temperature calculation model for rolling production lines calculates W according to the following formula (7).

[0056]

[0057] In equation (7), ρ is the density coefficient of the strip, Cp is the specific heat coefficient of the strip, V is the volume of the strip, and Q is the heat lost by radiation of the strip. As known, the temperature calculation model of the production line calculates Q according to the following equation (8).

[0058] Q=ε*A*σ(T 环境 -T 入口 (8)

[0059] In equation (8), ε is the thermal emissivity coefficient, A is the emissivity coefficient, σ is the Stefan-Boltzmann constant, and T 环境 It refers to the ambient temperature.

[0060] In this embodiment, W = 0.895℃ / second is calculated using the existing temperature calculation model of the rolling production line.

[0061] After calculating Tv and T, iteratively calculate Tv, t1, T, T temperature drop, and T1 starting from the initial value according to the oscillation time. S4. Compare the T1 calculated in each iteration with T.

[0062] If |T1-T| ≥ 1, then repeat step S3;

[0063] If |T1-T| < 1, then stop the calculation, output the currently calculated swing time t1 as the time when the strip enters the swing, and execute the swing.

[0064] The following is a detailed explanation of steps S3 and S4, with the initial oscillation time starting from 0 to iteratively calculate t1, temperature drop T, and T1 as follows:

[0065] 1) Calculation of Tv and T

[0066] The measured roughing mill exit temperature of the previously rolled strip was 867℃. The initial target roughing mill exit temperature correction value Tv0 = 0. Therefore, dR = 867 - 860 = 7℃.

[0067] Tv=0+dR*Ga=7*0.7=4.9℃,

[0068] T=T0-Tv=860-4.9=855.1℃;

[0069] 2) Calculation of swing time

[0070] First calculation

[0071] If the initial swing time is 0 seconds, then

[0072] Temperature drop T = W * 0 = 0,

[0073] T1 = T_inlet = 1040℃

[0074] Since 1040 is relatively large compared to 855.1, i.e., |1040-855.1|≥1, the iterative calculation continues;

[0075] Second calculation

[0076] The previous iteration calculated the oscillation time t10 = the initial oscillation time = 0 seconds, and the previous iteration calculated the strip exit temperature at R2 as T10 = 1040℃.

[0077] The duration of this oscillation is t1 = 0 + (1040 - 855.1) * 0.1 = 18.49 seconds.

[0078] Temperature drop T = W * t1 = 0.895 * 18.49 ≈ 16.55℃

[0079] T1 = T_inlet - T_temperature drop = 1040 - 16.55 = 1023.45℃

[0080] Since 1023.45 is relatively large compared to 855.1, i.e., |1023.45-855.1|≥1, the iterative calculation continues;

[0081] Third calculation

[0082] The previous iteration calculated the oscillation time t10 = 18.49 seconds, and the previous iteration calculated the strip exit temperature at R2 to be T10 = 1023.45℃. Therefore...

[0083] The oscillation time calculated in this iteration is t1 = 18.49 + (1023.45 - 855.1) * 0.1 = 35.325 seconds.

[0084] Temperature drop T = W * t1 = 0.895 * 35.325 ≈ 31.62℃

[0085] T1 = T_inlet - T_temperature drop = 1040 - 31.62 = 1008.38℃

[0086] Since 1008.38 is relatively large compared to 855.1, i.e., |1008.38-855.1|≥1, the iterative calculation continues;

[0087] Fourth calculation

[0088] The previous iteration calculated the oscillation time t10 = 35.325 seconds, and the previous iteration calculated the strip exit temperature at R2 T10 = 1008.38℃. Therefore...

[0089] The oscillation time calculated in this iteration is t1 = 35.325 + (1008.38 - 855.1) * 0.1 = 50.653 seconds.

[0090] Temperature drop T = W * t1 = 0.895 * 50.653 ≈ 45.33℃

[0091] T1 = T_inlet - T_temperature drop = 1040℃ - 45.33 = 994.67℃

[0092] Since 994.67 is significantly larger than 855.1 (i.e., |994.67 - 855.1| ≥ 1), the iterative calculation continues. Because subsequent iterative calculations are identical to the above, a detailed description is omitted. All iterative calculation results are shown in Table 2. Until the forty-seventh iteration, the current oscillation time t1 = 195.76 seconds ≈ 196 seconds, T1 = 856.03℃, and T = 855.1℃ are calculated. Since |856.03 - 855.1| < 1 at this point, the calculation of oscillation times t1 and T1 is stopped. The currently calculated oscillation time of 200 seconds is output as the time for the strip to enter the oscillation, and the oscillation is executed.

[0093] Table 2

[0094]

[0095]

[0096] The iterative calculations of the oscillation time and the roughing mill (R2) exit temperature described above started from an initial oscillation time of 0 and were performed 47 times to determine the final oscillation time. The iterative process is lengthy. To simplify the calculations, it is practically possible to start the iterations with an initial oscillation time of 100 or 150 seconds, thus reducing the number of iterations. The initial oscillation time of 100 or 150 seconds is chosen based on experience.

[0097] Example 2

[0098] This embodiment is a further improvement based on Embodiment 1. The difference is that, except for the fact that it is the same as Embodiment 1, the calculation of Tv in step S3 is expressed as follows (6).

[0099] Tv=Tv0+dR*Ga+dF*(1-Ga) (6),

[0100] In formula (6), dF is the current temperature deviation of the finishing entry of the rolled strip. dF = the current measured temperature of the finishing entry of the rolled strip - the target temperature of the finishing entry. The target temperature of the finishing entry is required by the rolling production line. In this embodiment, the target temperature of the finishing entry is 840℃.

[0101] Because the change in Tv calculation leads to corresponding changes in steps 3 and S4, the following is a detailed explanation of the changed steps S3 and S4 in this embodiment. Starting from the initial value of the oscillation time of 100, the specific iterative calculation of t1, temperature drop T, and T1 is as follows:

[0102] 1) Calculation of Tv and T

[0103] The measured roughing mill exit temperature of the previously rolled strip was 867℃. Therefore, dR = 867 - 860 = 7℃.

[0104] If the measured entry temperature of the finishing mill for the strip in the previous rolling process was 845℃, then dR = 845 - 840 = 5℃.

[0105] If the initial roughing mill target exit temperature correction value Tv0 = 0, then

[0106] Tv=0+dR*Ga+dF*(1-Ga)=7*0.7+5*0.3=6.4℃

[0107] T=T0-Tv=860-6.4=853.6℃

[0108] 2) Calculation of swing time

[0109] First calculation

[0110] If the initial swing time is 100 seconds, then...

[0111] T 温降 =W*t1=0.895*100=89.5℃

[0112] T1 = T_entry - T_entry 温降 =1040-89.5=950.5℃

[0113] Since 950.5 is relatively large compared to 853.6, i.e., |950.5-853.6|≥1, the iterative calculation continues;

[0114] Second calculation

[0115] The previous iteration calculated the oscillation time t10 = the initial oscillation time = 100 seconds, and the previous iteration calculated the strip exit temperature at R2 as T10 = 950.5℃. Therefore...

[0116] The oscillation time in this iteration is t1 = 100 + (950.5 - 853.6) * 0.1 = 109.69 seconds.

[0117] T 温降 =W*t1=0.895*109.69≈98.17℃

[0118] T1 = T_entry - T_entry 温降=1040-98.17=941.83℃

[0119] Since 941.83 is relatively large compared to 853.6, i.e., |941.83-853.6|≥1, the iterative calculation continues.

[0120] Third calculation

[0121] The previous iteration calculated the oscillation time t10 = 109.69 seconds, and the previous iteration calculated the strip exit temperature at R2 to be T10 = 941.83℃. Therefore...

[0122] The oscillation time calculated in this iteration is t1 = 109.69 + (941.83 - 853.6) * 0.1 = 118.513 seconds.

[0123] T 温降 =W*t1=0.895*118.513≈106.07℃

[0124] T1 = T_entry - T_entry 温降 =1040-106.07=933.93℃

[0125] Since 933.93 is relatively large compared to 853.6, i.e., |933.93-853.6|≥1, the iterative calculation continues;

[0126] Fourth calculation

[0127] The previous iteration calculated the oscillation time t10 = 118.513 seconds, and the previous iteration calculated the strip exit temperature at R2 T10 = 933.93℃. Therefore...

[0128] The oscillation time calculated in this iteration is t1 = 118.513 + (933.93 - 853.6) * 0.1 ≈ 126.55 seconds.

[0129] T 温降 =W*t1=0.895*126.55≈113.26℃

[0130] T1 = T_entry - T_entry 温降 =1040℃ - 113.26 = 926.74℃

[0131] Since 926.74 is significantly larger than 853.6 (i.e., |926.74 - 853.6| ≥ 1), the iterative calculation continues. Because subsequent iterative calculations are identical to the above, a detailed description is omitted. All iterative calculation results are shown in Table 3 below. Until the 39th iteration, the current swing time t1 = 198.6 seconds ≈ 199 seconds, T1 = 853.28℃, and T = 853.6℃. Since |853.28 - 853.6| < 1 at this point, the calculation of swing times t1 and T1 is stopped. The currently calculated swing time of 199 seconds is output as the time for the strip to enter the swing phase, and the swing is executed.

[0132] Table 3

[0133]

[0134]

[0135] The above description is only a preferred embodiment of the present invention, but the present invention is not limited thereto. For example, 1) G in formula (3) can take other values ​​within the range of 0.05-0.15; 2) Ga in formula (5) can take other values ​​within the range of 0.65-0.75; 3) The initial value of the oscillation time can be other values ​​within the range of 0-180 seconds. All equivalent substitutions or equivalent changes made to the concept and technical solutions of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for precise control of the exit temperature of IF steel rib strip roughing mill, involving two roughing mill stations R1 and R2 in the rolling production line and an existing temperature calculation model of the rolling production line, comprising the following steps: S1. Set the roughing mode of one pass for R1 and seven passes for R2, and let the seventh pass of R2 pass empty. Set the swing zone between the R1 mill and the R2 mill, and enter the swing zone after the R2 mill completes the sixth pass to start calculating the swing time and swinging. S2. Read the temperature calculation model and calculate the inlet temperature T of the strip in the swing zone in the sixth pass of R2. 入 mouth; S3. Calculate the exit temperature T1 of the strip at R2 using the following formula (1) iteratively. T1 = T_inlet - T_temperature drop (1), In equation (1), T1 is the outlet temperature of the strip at R2 calculated iteratively, and T_temperature drop is the temperature drop of the strip from the inlet of the pre-swinging zone of R2 to the outlet of R2, calculated according to equation (2). Temperature drop T = W * t1(2), In equation (2), W is the temperature drop per unit time of the strip from the inlet to the outlet of R2 in the swing zone before R2 calculated by the temperature calculation model, and t1 is the swing time calculated in the current iteration after iteration. The iteration calculation of t1 is expressed as follows: equation (3). t1=t10+(T10-T)*G, (3), In equation (3), T10 is the outlet temperature of the strip at R2 calculated in the previous iteration, G is a coefficient in seconds / ℃, and t10 is the oscillation time calculated in the previous iteration. T is the roughing mill correction target exit temperature, which is corrected based on the measured roughing mill exit temperature and is calculated according to the following formula (4). T = T0 - Tv (4), In equation (4), T0 is the target exit temperature of the roughing mill R2 specified in the production process, and Tv is the correction value of the target exit temperature of the roughing mill for the current rolled strip. The calculation of Tv is expressed as in equation (5). Tv=Tv0+dR*Ga (5), In equation (5), Tv0 is the correction value of the target exit temperature of the previous rolled strip, Ga is a constant, dR is the deviation of the exit temperature of the previous rolled strip, and dR = the measured exit temperature of the previous rolled strip - the target exit temperature of the previous rolled strip T0. The temperature drop and T1 are calculated iteratively starting from the initial value according to the oscillation time; S4. Compare T1 calculated in each iteration with T. If |T1-T| ≥ 1, then repeat step S3; If |T1-T| < 1, then stop the calculation, output the swing time t1 calculated in the current iteration as the swing time of the strip entering the swing zone, and execute the swing.

2. The method for precise control of the exit temperature of IF steel ferrite strip roughing mill according to claim 1, characterized in that: The Tv iterative calculation in step S3 is expressed by the following equation (6). Tv=Tv0+dR*Ga+dF*(1-Ga) (6), In formula (6), dF is the temperature deviation of the previous strip steel finishing entry. dF = the measured temperature of the previous strip steel finishing entry - the target temperature of the finishing entry. The target temperature of the finishing entry is required by the rolling production line.

3. The method for precise control of the exit temperature of IF steel ribbed strip roughing mill according to claim 1 or 2, characterized in that: The W in equation (2) is calculated by the temperature calculation model according to equation (7). In equation (7), ρ is the density coefficient of the strip, Cp is the specific heat coefficient of the strip, V is the volume of the strip, and Q is calculated according to equation (8). Q=ε*A*σ(T 环境 -T 入口 ) (8) In equation (5), ε is the thermal emissivity coefficient, A is the emissivity coefficient, σ is the Stefan-Boltzmann constant, and T 环境 It refers to the ambient temperature.

4. The method for precise control of the exit temperature of IF steel ribbed strip roughing mill according to claim 1 or 2, characterized in that: In equation (3), G is 0.05-0.15, in equation (5) Ga is 0.65-0.75, and the initial value of the oscillation time is 0-180 seconds.

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