CN-117299827-B - Accurate control method for rough rolling outlet temperature of IF steel ferrite strip steel

Abstract

The invention relates to an IF steel element strip steel rough rolling outlet temperature accurate control method, and belongs to the technical field of control methods specially applicable to metal rolling mills. According to the method, a rolling interval is set between an R1 rolling mill and an R2 rolling mill in an existing rolling production line, an existing temperature calculation model of the rolling production line is utilized to read an inlet temperature of the R2 band steel in a rolling area in the 6 th pass, the rolling time, temperature drop of the band steel from an inlet of the R2 front rolling area to an outlet of the R2 band steel and an outlet temperature T1 of the band steel in the R2 band steel are calculated in an iterative mode, meanwhile, the rough rolling correction target outlet temperature is corrected according to deviation between the measured temperature of the band steel in the previous rolling process and a specified rough rolling target outlet temperature to obtain a rough rolling correction target outlet temperature T, T1 is gradually made to approach T to enable T1 to reach or approach the rough rolling R2 target outlet temperature T0 required by production more accurately, the calculated rolling time closest to T is used as the actual rolling time, and the rolling is executed, and the rough rolling outlet temperature is controlled to reach the specified target outlet temperature.

Inventors

• TAN YUNYU
• DONG GANG
• LI MEIHUA
• CHEN CHEN

Assignees

• 上海梅山钢铁股份有限公司

Dates

Publication Date

20260505

Application Date

20220621

Claims (4)

1. 1. An IF steel element strip steel rough rolling outlet temperature accurate control method relates to two rough rolling stations R1 and R2 arranged on a rolling production line and an existing temperature calculation model of the rolling production line, and comprises the following steps: S1, setting a rough rolling mode of one pass of R1 and seven passes of R2, wherein the seventh pass of R2 is free, setting a swinging area between an R1 rolling mill and an R2 rolling mill, entering the swinging area after the sixth pass of the R2 rolling mill is finished, and calculating swinging time and swinging; S2, reading an inlet temperature T Into (I) of the band steel in a swinging area calculated in a sixth pass of R2 by the temperature calculation model; S3, iteratively calculating the outlet temperature T1 of the strip steel at R2 according to the following formula (1), T1=tset-tset drop (1), In the formula (1), T1 is the outlet temperature of the strip steel at R2 through iterative calculation, T temperature drop is the temperature drop of the strip steel from the inlet of the R2 front swinging area to the outlet of the R2, and is calculated according to the following formula (2), T temperature drop = W x T1 (2), In the formula (2), W is the temperature drop of the strip steel calculated by the temperature calculation model in a fixed unit time from an inlet of an R2 front swinging area to an outlet of the R2, t1 is the swinging time calculated by the current iteration through iterative calculation, t1 is expressed by the following formula (3), t1=t1 0 +(T1 0 -T)*G, (3), In the formula (3), T1 0 is the outlet temperature of the strip steel at R2 calculated in the previous iteration, G is the coefficient with the unit of seconds/DEGC, T1 0 is the swing time calculated in the previous iteration, T is the rough rolling correction target outlet temperature corrected according to the actually measured rough rolling outlet temperature, and is calculated according to the following formula (4), T=T0-Tv (4), In the formula (4), T0 is the target outlet temperature of the rough rolling R2, tv is the target outlet temperature correction value of the rough rolling of the current rolled strip steel, tv is calculated as expressed in the formula (5), Tv=Tv0+dR*Ga (5), In the formula (5), tv0 is a rough rolling target outlet temperature correction value of the previously rolled strip steel, ga is a constant, dR is a deviation of the rough rolling outlet temperature of the previously rolled strip steel, dr=actual measured rough rolling outlet temperature of the previously rolled strip steel-rough rolling outlet target temperature T0; sequentially and iteratively calculating T1, T temperature drop and T1 from an initial value according to the swinging time; s4, comparing the T1 calculated in each iteration with the T, If |T1-T|is not less than 1, repeating the step S3; if |T1-T| <1, stopping calculation, outputting the current iteration calculation oscillation time T1 as the oscillation time of the strip steel entering the oscillation area, and executing oscillation.
2. 2. The method for precisely controlling the rough rolling outlet temperature of the IF steel ferrite strip according to claim 1, wherein Tv in the step S3 is calculated iteratively as expressed in the following formula (6), Tv=Tv0+dR*Ga+dF*(1-Ga) (6), In the formula (6), dF is the finish rolling inlet temperature deviation of the previously rolled strip, df=the actual finish rolling inlet temperature of the previously rolled strip-the finish rolling inlet target temperature, and the finish rolling inlet target temperature is required by the rolling line.
3. 3. The method for precisely controlling the rough rolling outlet temperature of an IF steel strip according to claim 1 or 2, wherein the W in the formula (2) is calculated by the temperature calculation model according to the following formula (7), In the formula (7), ρ is the density coefficient of the strip steel, cp is the specific heat coefficient of the strip steel, V is the volume of the strip steel, Q is calculated according to the following formula (8), Q=ε*A*σ(T Environment (environment) -T An inlet ) (8) In formula (5), ε is the emissivity coefficient, A is the emissivity coefficient, σ is the Stefan-Boltzmann constant, and T Environment (environment) is the ambient temperature.
4. 4. The method for precisely controlling the rough rolling outlet temperature of the IF steel body strip according to claim 1 or 2, wherein G in the formula (3) is 0.05-0.15, ga in the formula (5) is 0.65-0.75, and the initial value of the swing time is 0-180 seconds.

Description

Accurate control method for rough rolling outlet temperature of IF steel ferrite strip steel Technical Field The invention relates to a method for ensuring that the rough rolling outlet temperature control reaches the production requirement when IF steel element rolling is carried out, and belongs to the technical field of control methods specially applied to metal rolling mills. Background The IF steel ferrite rolling process is shown in figure 1, wherein strip steel is rolled by a stokehold roller way, a descaling box and an R1 rolling mill, the strip steel is subjected to reversible rolling by an R2 reversible rolling mill, the strip steel enters a hot coil box for coiling after the reversible rolling is completed, and is uncoiled after a hot coil box shovel blade is in place after the hot coil box is coiled, and the strip steel enters a finish rolling mill for rolling after uncoiling. The thermometer is generally arranged at the inlet and outlet of the R2 rolling mill and the finish rolling inlet, and a section of area from the heating furnace to the outlet of the R1 rolling mill (the inlet of the R2 rolling mill) cannot be accurately measured due to factors such as environment and scale on the surface of strip steel, so the thermometer is not designed. The rolling temperature of the IF steel ferrite strip is required to be that the tapping temperature of a heating furnace is about 1120 ℃, the temperature of a finish rolling inlet is less than or equal to 840 ℃, after rough rolling is finished, the temperature of the strip is reduced by 280 ℃ before the finish rolling inlet, and the inlet temperature required for finish rolling is less than or equal to 840 DEG, so that the target temperature of a rough rolling outlet is required to be controlled to be less than or equal to 860 DEG (the temperature between a pyrometer of a rough rolling R2 outlet and a pyrometer of the finish rolling inlet is usually reduced to about 20 ℃). For a rolling line without water cooling equipment, a swing area is generally increased between an R1 rolling mill and an R2 rolling mill, a rough rolling mode is set to be 1+7, the last pass is free (namely, R1 rolling pass, R2 pass and R2 pass 7) and after 7 passes of strip steel rolling, the swing area is subjected to swing cooling by utilizing air cooling and heat radiation. When the swinging is finished, operators observe a thermometer of the strip steel at the inlet or the outlet of the R2, and after the temperature is determined to reach the requirement, the swinging is finished by manual control. However, the control method cannot stably ensure that the actual rough rolling outlet temperature reaches the required rough rolling outlet target temperature. The Chinese patent of the prior publication No. CN111250545A discloses a control system and a method for reducing the super-thick rate of a swinging steel coil, and aims at solving the problem that the thickness of a finish rolling outlet is super-thick when strip steel swings. The China patent of the prior publication No. CN103990653A discloses a method for ensuring the hit precision of the finish rolling inlet temperature, which is used for positively calculating the rough rolling outlet temperature T2 according TO the tapping temperature TO and reversely calculating the rough rolling outlet temperature T1 according TO FT0 and speed. The maximum swing time of the iterative calculation for 300ms and 180 times of the upper limit of the iterative calculation according to the instruction of the method is reduced by 82 degrees, and the total temperature of rough rolling is generally required to be reduced by about 130 degrees, so that the rough rolling outlet temperature requirement of IF steel production cannot be met. Disclosure of Invention The invention aims to solve the technical problem of accurately reaching the rough rolling target outlet temperature required by production in the rolling of the IF steel ferrite strip steel. The invention provides a technical scheme for solving the technical problems, which is a precise control method for the rough rolling outlet temperature of IF steel element strip steel, relates to two rough rolling stations R1 and R2 arranged on a rolling production line and an existing temperature calculation model of the rolling production line, and comprises the following steps: S1, setting a rough rolling mode of one pass of R1 and seven passes of R2, wherein the seventh pass of R2 is free, setting a swinging area between an R1 rolling mill and an R2 rolling mill, entering the swinging area after the sixth pass of the R2 rolling mill is finished, and calculating swinging time and swinging; S2, reading the temperature calculation model, and calculating the inlet temperature T An inlet of the strip steel in a swinging area in the sixth pass of R2; S3, iteratively calculating the outlet temperature T1 of the strip steel in R2 according to the following formula (1), T1=tset-tset drop (1), In the formu