Precision rolling method for high-speed steel rolls

Abstract

The present invention belongs to the technical field of metallurgical rolling in metallurgical science and technology, and specifically relates to a finish rolling method for high-speed steel rolls, including: adjusting the load distribution of the rolling mill according to the rolling pressure; adding a roll correction coefficient in the calculation of the rolling pressure according to the roll type. The finish rolling method for high-speed steel rolls of the present invention reduces the rolling pressure deviation from a maximum of 40% to within ±10%, and no stainless steel overcurrent phenomenon occurs, realizing the stable rolling of high-speed steel rolls in the hot strip rolling production line and achieving remarkable economic benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical rolling in metallurgical science and technology, and particularly relates to a finish rolling method for high-speed steel rolls. Background Art

[0002] The layout diagram of the hot continuous rolling mill line is as Figure 1 shown, and it is divided into a furnace area, a rough rolling area, a finish rolling area, and a coiling area. The main production process of this hot continuous rolling production line is that the slab is first heated in a heating furnace according to the temperature specified by the process. After being heated to the target temperature, it first enters the rough rolling mill for rolling. Among them, the rough rolling vertical roll controls the width, and the horizontal roll controls the thickness. Reversible rolling is carried out in the rough rolling mill set, generally for 5 to 7 passes.

[0003] After being rolled by the rough rolling mill set, the strip steel reaches the preset target thickness, width, and temperature. Then it enters the finish rolling mill set for seven-stand horizontal roll continuous rolling to make the strip steel reach the preset target thickness and temperature. Finally, the strip steel is formed into a steel coil by a coiler.

[0004] The present invention mainly focuses on the use of high-speed steel rolls in the finish rolling stands of the 1549 production line. Before using high-speed steel rolls, the high nickel-chromium rolls were selected for the 1549 hot continuous rolling production line of Taiyuan Iron and Steel. Compared with high nickel-chromium rolls, high-speed steel rolls have the characteristics of high strength and high hardness, and have high wear resistance and heat fatigue resistance when applied to strip hot rolling mills. However, high-speed steel rolls will cause high-stress cracks under conditions such as overheating and impact. Since the last three stands, namely F4 to F6, are prone to phenomena such as head rolling breakage and tail whipping, the determined solution when selecting high-speed steel rolls is to select high-speed steel rolls for the stands of high-speed steel rolls required in the first four stands F0 to F3 according to the requirements of different steel grades. High-speed steel rolls can be selected for any of the 0 to 4 stands, while the original high nickel-chromium rolls are still used for F4 to F6.

[0005] However, after selecting high-speed steel rolls, the following rolling characteristics were found during the rolling process:

[0006] When high-speed steel rolls are applied to a certain stand, the actual rolling pressure of this stand is 5% to 40% higher than that of high nickel-chromium rolls. For different stands and different steel grades, the increase range of the rolling pressure is different. At the same time, the increase in rolling pressure is related to the inlet temperature (TE), reduction rate (EPS), work roll diameter (WRR), and rolling speed (VU) of this stand.

[0007] Under the condition that the rolling pressure of this stand increases, the current of this stand is 3 to 10% lower than that of high nickel-chromium rolls.

[0008] Due to the inaccurate prediction of the finish rolling pressure after applying high-speed steel rolls, that is, the predicted value (calculated value) is too different from the actual value, it causes difficulties in threading the strip steel and multiple scrap steel faults. Summary of the Invention

[0009] In view of the above phenomena, based on the analysis of the characteristics of high-speed steel rolls and statistical data, the present invention provides a finishing rolling method for high-speed steel rolls.

[0010] Specifically, the finishing rolling method for high-speed steel rolls of the present invention includes: adjusting the load distribution of the stands according to the rolling pressure; adding a roll correction coefficient in the calculation of the rolling pressure according to the roll type.

[0011] The technical solution of the present invention has the following beneficial effects:

[0012] (1) For the finishing rolling method for high-speed steel rolls of the present invention, the rolling pressure deviation is reduced from a maximum of 40% to within ±10%, and the stainless steel overcurrent phenomenon does not occur, realizing the stable rolling of high-speed steel rolls in the hot continuous rolling production line and achieving remarkable economic benefits;

[0013] (2) For the finishing rolling method for high-speed steel rolls of the present invention, the thickness of high-grade silicon steel is thinned from the thinnest 2.3 mm to the thinnest 2.1 mm, and the thickness of plain carbon steel is thinned from the thinnest 1.8 mm to the thinnest 1.5 mm. Brief Description of the Drawings

[0014] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention.

[0015] Figure 1 is the layout diagram of the hot continuous rolling mill line equipment;

[0016] Figure 2 is the rolling pressure control flow chart of the hot continuous rolling.

[0017] Symbol Description: 1 is the heating furnace (4 units); 2 is the high-pressure water descaling box; 3 is the roughing vertical roll mill (VE0); 4 is the roughing horizontal roll mill (R0); 5 is the heat preservation cover; 6 is the rotary drum type crop shear; 7 is the finishing stands (7 stands); 8 is the convexity gauge; 9 is the width gauge; 10 is the thickness gauge; 11 is the flatness gauge; 12 is the coiler. Detailed Embodiments

[0018] In order to fully understand the purpose, features and effects of the present invention, the present invention will be described in detail through the following specific embodiments. Except for the following content, the process methods of the present invention all adopt the conventional methods or devices in the art. Unless otherwise specified, the following terms have the meanings commonly understood by those skilled in the art.

[0019] The overall technical solution of the present invention is to add a compensation coefficient on the basis of the original rolling pressure control method according to the characteristics of high-speed steel rolls, so as to conform to the rolling characteristics of high-speed steel rolls, improve the prediction value accuracy, and thus achieve high-precision prediction of the finishing rolling pressure for high-speed steel rolls. At the same time, according to the characteristic that the applied current of high-speed steel rolls decreases, the load distribution between stands (i.e., the initial reduction ratio of each stand) is adjusted to achieve the purpose of balanced load distribution. On the basis of the above two technical applications, it is realized that the finishing stands F0 to F3 can use high-speed steel rolls in any 1 stand, any 2 stands, any 3 stands or 4 stands according to the steel type requirements, so as to realize the arbitrary use of high-speed steel rolls in the first 4 stands of the finishing mill as needed.

[0020] The control system of hot strip mill adopts two-level computer control, namely process control computer (L2 computer) control and basic automation computer (L1 computer) control. The present invention mainly focuses on the rolling pressure control of the finishing mill. The rolling pressure control process is as follows ( Figure 2 ):

[0021] S1: Calculate the rolling pressure in the L2 computer;

[0022] S2: Send the calculation result of the L2 computer to the SDH module (setting proxy module) of the L1 computer in the form of a message;

[0023] S3: Establish a communication channel from the SDH module to the pressure control module;

[0024] S4: Read the message data value, transfer it to the drive system control block, and execute and control the specific parameters.

[0025] The present invention first makes a creative improvement on the rolling pressure control method for the calculation of rolling pressure by the L2 computer.

[0026] Before the implementation of the present invention, the calculation process of rolling pressure is as follows:

[0027] F(i) = nnfk(i) * MH(i) * EPS(i) (1)

[0028] Among them, i represents the finishing mill stand number;

[0029] F(i) represents the calculated rolling pressure of this stand of the finishing mill, KN;

[0030] nnfk(i) represents the pressure correction coefficient of the i-th stand, dimensionless quantity;

[0031] MH(i) represents the hardness value of the steel at the i-th stand, KN;

[0032] EPS(i) represents the reduction ratio of the i-th stand, %.

[0033] The calculation process of the pressure correction coefficient nnfk(i) for the i-th stand is as follows: The pressure correction coefficient nnfk(i a ) for each rolled steel piece is recorded together with the corresponding steel grade, thickness, width, and chemical composition to establish a database; where the calculation method of nnfk(i a ) is as follows:

[0034] nnfk(i a ) = nnfk(i 0 ) + 0.68 * (F(i 0 ) - F(i 00 )) / F(i 00 )

[0035] Among them, nnfk(i 0 ) represents the pressure correction coefficient of the previous steel piece, which is a dimensionless quantity; F(i 0 ) represents the actual pressure during the rolling of the previous steel piece, in KN; F(i 00 ) represents the calculated pressure during the rolling of the previous steel piece, in KN.

[0036] The confirmation of the pressure correction coefficient nnfk(i) is divided into two cases: long genetic value and short genetic value.

[0037] The determination conditions for the long genetic value are at least one of the following conditions: 1) When the steel grade of this steel piece is different from that of the previous steel piece, take the long genetic value; 2) When the thickness of this steel piece is greater than or equal to 10% compared with the thickness of the previous steel piece, take the long genetic value; 3) When the width of this steel piece is greater than or equal to 10% compared with the width of the previous steel piece, take the long genetic value. As long as one of the above three conditions is met, take the long genetic value.

[0038] The method for determining nnfk(i) according to the long genetic value is: Take the average value of nnfk(i a ) of the 30 steel pieces closest in the pressure correction coefficient nnfk(i a ) database as the nnfk(i) of this steel piece; when the number of similar steels in the database is less than 30 steel pieces, take the average value of nnfk(i a ) of the actual number of steel pieces; when there is no such steel grade in the database, nnfk(i) takes the default value of 1.0.

[0039] The determination condition for the short genetic value is: When the steel grades are the same and the changes in thickness and width are less than 10%, take the short genetic value, that is, the calculated value of nnfk(i a ) of the previous steel piece.

[0040] The hardness value MH(i) of the steel at the i-th stand can be tested according to the standard GB / T 231-2002. The hardness in this invention refers to Brinell hardness (HB).

[0041] The pressing rate EPS(i) of the i-th rack has the following specific meaning:

[0042] EPS(i)=(THEN(i)-THEN(i+1)) / THEN(i) (2)

[0043] Wherein, THEN(i) represents the inlet thickness of the i-th rack, mm; THEN(i+1) represents the outlet thickness of the i-th rack, that is, the inlet thickness of the i+1-th rack, mm.

[0044] The present invention mainly proposes a rolling method for F0-F3 using high-speed steel rollers for rolling pressure and load distribution, which includes two aspects.

[0045] 1. Load distribution control method for high-speed steel rolls

[0046] After applying high-speed steel rolls, the differences between high-speed steel rolls and high-nickel-chromium rolls were summarized. It was found that after a certain stand applied high-speed steel rolls, on the one hand, the rolling pressure increased, while on the other hand, the current of the stand was reduced by 3-10% compared with the high-nickel-chromium rolls. In order to optimize the current control, according to the rolling pressure of each steel type, the automatic load distribution function is added. The overall technical idea of ​​adjusting the load distribution is:

[0047] 1) When the rolling pressure of the stand is within a range, that is, the rolling pressure may cause overcurrent during the rolling process under the condition of high nickel-chromium rolls, but the maximum rolling pressure that may be reached during the rolling process under the condition of high-speed steel rolls will not exceed the maximum rolling pressure limit value (F0: 40000KN; F1: 34000KN; F2: 34000KN; F3: 34000KN), the load distribution of the stand is appropriately increased.

[0048] 2) Under the condition of high-speed steel rolls, when the rolling pressure of the stand is too large and may reach the maximum value, the load distribution of the stand is no longer increased. The main reason is that if the load distribution of the stand is increased, although the current does not flow, it is easy for the maximum rolling pressure to exceed the limit value during the rolling process.

[0049] 3) When the rolling pressure of the stand is too small, the load distribution of the stand will not be increased. The main reason is that in this case, the rolling pressure margin of each finishing rolling stand is large, and there is no need to adjust the load distribution.

[0050] According to the above load adjustment principles, through continuous test and adjustment, the load adjustment rules for various steel grades and specifications after each frame uses high-speed steel rolls are determined as shown in Table 1.

[0051] Table 1: Load adjustment after using high-speed steel rolls

[0052]

[0053]

[0054] Note: 1) The above [a, b) means "a ≤ index < b". For example, [3.5, 5.0) means "3.5mm ≤ thickness < 5.0mm"; 2) Load adjustment refers to the adjustment of the initial reduction rate. For example, if the adjustment amount of F0 is +3, it means that the initial reduction rate of F0 increases by 3%.

[0055] 2. Rolling pressure control method for high-speed steel rolls

[0056] Due to the large friction of high-speed steel rolls, the rolling pressure increases by 15% - 40% compared with that when using high-nickel-chromium rolls. The increased range varies under different stands, different steel grades, and different working conditions. To improve the prediction accuracy of rolling pressure, the following rolling pressure calculation method is invented:

[0057] F(i) = nnfk(i)*MH(i)*EPS(i)*(1.0 + coff_rolltype(i)) (3)

[0058] Among them, i represents the finishing mill stand number;

[0059] F(i) represents the calculated rolling pressure of this stand of the finishing mill, kN;

[0060] nnfk(i) represents the pressure correction coefficient of the i-th stand, dimensionless;

[0061] MH(i) represents the hardness value of the steel at the i-th stand, kN;

[0062] EPS(i) represents the reduction rate of the i-th stand, %;

[0063] coff_rolltype(i) represents the roll correction coefficient, dimensionless.

[0064] Among them, the roll correction coefficient coff_rolltype(i) is used to correct the influence of the roll type on the rolling pressure.

[0065] 1) When the roll is a high-nickel-chromium roll, coff_rolltype(i) = 0.

[0066] 2) When the roll is a high-speed steel roll, coff_rolltype(i) has a strong correlation with the stand, steel grade, and working conditions. After the stand and steel grade are determined, through repeated tests and summarizing the rules, coff_rolltype(i) is related to four parameters: the inlet temperature (TE), reduction ratio (EPS), work roll diameter (WRR), and rolling speed (VU) of this stand. However, the influence is very complex, and under different stands and different steel grades, its influence weight and influencing parameters are different. After a large amount of data regression analysis, the specific calculation methods shown in the following table are obtained.

[0067] The specific value details of the roll correction coefficient coff_rolltype(i) are shown in Table 2.

[0068] Table 2: Roll Correction Coefficient Table

[0069]

[0070]

[0071] The determination methods of the pressure correction coefficient nnfk(i) of the i-th stand, the hardness value MH(i) of the steel at the i-th stand, and the reduction ratio EPS(i) of the i-th stand in Equation (3) are the same as those of the corresponding parameters in Equation (1), and the present invention will not elaborate here.

[0072] In practice, compared with the prior art, when using high-speed steel rolls, the rolling pressure control method of the present invention controls the rolling pressure deviation within the range of ±10%. The load distribution adjustment of the present invention makes the load distribution of the finishing stands more reasonable. The thickness limit specification of plain carbon steel is thinned by 0.3 mm, and the limit specification of silicon steel is thinned by 0.2 mm.

[0073] Embodiment

[0074] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments. The experimental methods without specific conditions in the following embodiments are carried out according to conventional methods and conditions.

[0075] Embodiment 1:

[0076] This embodiment rolls 300 series stainless steel, coil number: 929652301, steel grade: 304; billet thickness 200 mm, billet width 1240 mm, rough rolling target thickness 35 mm; strip finished product target thickness 5.45 mm, target width 1255 mm.

[0077] High-speed steel rolls are used for F0 - F3 of this piece of steel.

[0078] 1. Load distribution for high-speed steel rolls

[0079] The load distribution (%) of each stand in this specification is: 60.7, 58.8, 54.0, 49.2, 37.0, 31.0, 23.8. According to Table 1, the load distribution is not adjusted.

[0080] 2. Rolling pressure control for high-speed steel rolls

[0081] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each piece of steel are as follows:

[0082] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 60.7 58.8 54 49.2 37 31 23.8 MH kN 68593 59670 57079 65987 67101 66045 76791 TE ℃ 1032.94 1030.72 1025.87 1021.46 1016.59 1010.57 1004.77 HE mm 35.722 24.6 17.183 12.425 9.29 7.528 6.331 EPS ％ 31.1 30.2 27.7 25.2 19 15.9 12.2 WHEN mm 1294 1294 1294 1294 1294 1294 1294 WRR mm 370.55 329.5 312.1 319.2 317.3 303.1 336.25 VU m / s 1.18 1.69 2.34 3.16 3.96 4.76 5.49 nnfk 1.041 0.908 0.959 0.831 0.824 0.922 0.946

[0083] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0084] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1032.94 - 1.52198 * 31.1% - 0.000095 * 370.55 - 0.12192 * 1.18 = 0.2946784

[0085] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1030.72 - 0.34882 * 30.2% - 0.001476 * 329.5 - 0.00283 * 1.69 = 0.199103

[0086] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1025.87 - 0.9329 * 27.7% - 0.001742 * 312.1 - 0.02801 * 2.34 = 0.2771007

[0087] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1021.46 - 0.5923 * 25.2% - 0.001162 * 319.2 - 0.00581 * 3.16 = 0.1941036

[0088] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0089] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.041 * 68593 * 31.1% * (1.0 + 0.2946784) = 28751.0 (KN)

[0090] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.908 * 59670 * 30.2% * (1.0 + 0.199103) = 19620.3 (KN)

[0091] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.959 * 57079 * 27.7% * (1.0 + 0.2771007) = 19364.2 (KN)

[0092] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.831 * 65987 * 25.2% * (1.0 + 0.1941036) = 16500.7 (KN)

[0093] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0094] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 28751 19620 19364 16501 10505 9682 8863 Factual kN 28300 19020 19318 16197 10827 9637 8921 S calculation mm 21.099 16.584 12.414 9.602 6.932 5.981 5.812 S Actual mm 21.561 17.001 12.571 9.995 7.017 6.003 5.867

[0095] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0096] In the actual application process, the rolling pressure control only needs to be accurate to 1 kN.

[0097] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 5.45 mm, the actual thickness is 5.44 mm, the rolling is stable, there is no overcurrent phenomenon, and the rolling requirements are met.

[0098] Example 2:

[0099] This example rolls 300 series stainless steel, coil number: 929652501, steel grade: 304L; blank thickness 200 mm, blank width 1240 mm, rough rolling target thickness 35 mm; finished strip target thickness 4.00 mm, target width 1255 mm.

[0100] High-speed steel rolls are used for F0 - F3 of this piece of steel.

[0101] 1. Load distribution for high-speed steel rolls

[0102] The load distribution (%) for each stand of this specification is: 61.6, 63.6, 51.1, 46.5, 40.9, 36.0, 24.7. According to Table 1, the load adjustment amounts (%) for F0 - F3 are +3, +3, +4, +4 respectively. After adjustment, the load distributions (%) for F0 - F3 are: F0: 61.6 * (1 + 3%) = 63.4; F1: 63.6 * (1 + 3%) = 65.5; F2: 51.1 * (1 + 4%) = 53.1; F3: 46.5 * (1 + 4%) = 48.4. After adjustment, the load distribution (%) for F0 - F6 is 63.4, 65.5, 53.1, 48.4, 40.9, 36.0, 24.7.

[0103] 2. Rolling pressure control for high-speed steel rolls

[0104] The calculation data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each piece of steel are as follows:

[0105] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 63.4 65.5 53.1 48.4 40.9 36.0 24.7 MH kN 69000 60027 57523 66968 68521 67895 79529 TE ℃ 1030.83 1028.66 1024.46 1019.24 1013.98 1008.14 1002.73 HE mm 35.722 23.189 14.772 10.428 7.633 5.902 4.726 EPS ％ 35.1 36.3 29.4 26.8 22.7 19.9 13.7 WHEN mm 1285 1285 1285 1285 1285 1285 1285 WRR mm 370.55 329.5 312.1 319.2 317.3 303.1 336.25 VU m / S 1.05 1.64 2.35 3.25 4.24 5.34 6.29 nnfk 1.033 0.932 0.942 0.839 0.844 0.93 0.913

[0106] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0107] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1030.83 - 1.52198 * 35.1% - 0.000095 * 370.55 - 0.12192 * 1.05 = 0.2490158

[0108] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1028.66 - 0.34882 * 36.3% - 0.001476 * 329.5 - 0.00283 * 1.64 = 0.1764462

[0109] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1024.46 - 0.9329 * 29.4% - 0.001742 * 312.1 - 0.02801 * 2.35 = 0.2604579

[0110] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1019.24 - 0.5923 * 26.8% - 0.001162 * 319.2 - 0.00581 * 3.25 = 0.1837797

[0111] According to formula (3), the rolling pressures F0 - F3 are calculated as follows:

[0112] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.033 * 69000 * 35.1% * (1.0 + 0.2490158) = 31248.2 (KN)

[0113] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.932 * 60027 * 36.3% * (1.0 + 0.1764462) = 23891.4 (KN)

[0114] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.942 * 57523 * 29.4% * (1.0 + 0.2604579) = 20080.2 (KN)

[0115] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.839 * 66968 * 26.8% * (1.0 + 0.1837797) = 17825.2 (KN)

[0116] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0117]

[0118]

[0119] Note: In the table, F represents rolling pressure and S represents roll gap.

[0120] The deviation of rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 4.00 mm, and the actual thickness is 4.01 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0121] Example 3:

[0122] This example rolls 300 series stainless steel, coil number: 929652301, steel grade: 304; billet thickness 200 mm, billet width 1240 mm, rough rolling target thickness 35 mm; finished strip target thickness 2.985 mm, target width 1255 mm.

[0123] High speed steel rolls are used for F0 - F3 of this piece of steel.

[0124] 1. Load distribution for high speed steel rolls

[0125] The load distribution (%) for each stand of this specification is: 57.4, 52.2, 49.5, 45.1, 35.0, 30.4, 25.2. According to Table 1, the load distribution is not adjusted.

[0126] 2. Rolling pressure control for high speed steel rolls

[0127] The calculated data such as load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (VU), pressure correction factor nnfk, etc. for each stand of this piece of steel are as follows:

[0128] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 57.4 52.2 49.5 45.1 35 30.4 25.2 MH kN 69618 60952 59157 69422 71371 71576 85562 TE ℃ 1047.72 1043.16 1035.55 1029.54 1023.15 1015.39 1008.1 HE mm 35.73 21.488 13.698 8.994 6.177 4.676 3.69 EPS ％ 39.9 36.3 34.3 31.3 24.3 21.1 17.5 WHEN mm 1288 1288 1288 1288 1288 1288 1288 WRR mm 370.55 329.5 312.1 319.2 317.3 303.1 336.25 VU m / s 0.96 1.5 2.3 3.36 4.54 5.85 7.18 nnfk 0.931 0.883 0.827 0.722 0.801 0.88 0.876

[0129] According to Table 2, the roll correction factors coff_rolltype for each stand are calculated as follows:

[0130] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1047.72 - 1.52198 * 39.9% - 0.000095 * 370.55 - 0.12192 * 0.96 = 0.1920005

[0131] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1043.16 - 0.34882 * 36.3% - 0.001476 * 329.5 - 0.00283 * 1.50 = 0.1875434

[0132] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1035.55 - 0.9329 * 34.3% - 0.001742 * 312.1 - 0.02801 * 2.30 = 0.2201055

[0133] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1029.54 - 0.5923 * 31.3% - 0.001162 * 319.2 - 0.00581 * 3.36 = 0.1579909

[0134] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0135] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.931 * 69618 * 39.9% * (1.0 + 0.1920005) = 30826.2 (KN)

[0136] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.883 * 60952 * 36.3% * (1.0 + 0.1875434) = 23200.9 (KN)

[0137] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.827 * 59157 * 34.3% * (1.0 + 0.2201055) = 20474.0 (KN)

[0138] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.722 * 69422 * 31.3% * (1.0 + 0.1579909) = 18167.0 (KN)

[0139] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0140] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 30826 23201 20474 18167 13892 13290 13117 Factual kN 29300 22920 19957 18192 13881 12996 13001 S calculation mm 17.479 12.7 8.343 5.819 3.475 2.684 2.583 S Actual mm 17.952 12.986 8.879 5.963 3.692 2.964 2.601

[0141] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0142] In the actual application process, the rolling pressure control only needs to be accurate to 1 kN.

[0143] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.985 mm, and the actual thickness is 3.00 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0144] Example 4:

[0145] This example rolls 300 series stainless steel, coil number: 929656201, steel grade: 0CR18NI9DQ; billet thickness 180 mm, billet width 1020 mm, rough rolling target thickness 35 mm; finished strip target thickness 5.00 mm, target width 1034 mm.

[0146] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0147] 1. Load distribution for high-speed steel rolls

[0148] The load distribution (%) for each stand of this specification is: 64.0, 57.5, 51.7, 47.2, 37.0, 29.0, 22.5. According to Table 1, the load distribution is not adjusted.

[0149] 2. Rolling pressure control for high-speed steel rolls

[0150] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0151] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 64 57.5 51.7 47.2 37 29 22.5 MH kN 52295 45827 44458 52129 53530 53079 62293 TE ℃ 1054.36 1049 1040.16 1032.28 1024.35 1015.89 1007.6 HE mm 35.73 23.346 16.075 11.57 8.615 6.889 5.807 EPS ％ 34.7 31.1 28 25.5 20 15.7 12.2 WHEN mm 1069 1069 1069 1069 1069 1069 1069 WRR mm 375.5 331.5 305.1 320.5 317.6 311.75 330 VU m / s 0.96 1.39 1.94 2.63 3.34 4.01 4.63 nnfk 0.98 0.902 0.965 0.858 0.858 0.923 0.962

[0152] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0153] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1054.36 - 1.52198 * 34.7% - 0.000095 * 375.5 - 0.12192 * 0.96 = 0.2726652

[0154] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1049 - 0.34882 * 31.1% - 0.001476 * 331.5 - 0.00283 * 1.39 = 0.20735

[0155] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1040.16 - 0.9329 * 28% - 0.001742 * 305.1 - 0.02801 * 1.94 = 0.3028015

[0156] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1032.28 - 0.5923 * 25.5% - 0.001162 * 320.5 - 0.00581 * 2.63 = 0.1954751

[0157] According to formula (3), the rolling pressures F0 to F2 are calculated as follows:

[0158] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.98 * 52295 * 34.7% * (1.0 + 0.2726652) = 22632.4 (KN)

[0159] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.902 * 45827 * 31.1% * (1.0 + 0.20735) = 15521.1 (KN)

[0160] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.965 * 44458 * 28% * (1.0 + 0.3028015) = 15650.0 (KN)

[0161] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.858 * 52129 * 25.5% * (1.0 + 0.1954751) = 13634.8 (KN)

[0162] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0163] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 22632 15521 15650 13635 9186 7692 7311 Factual kN 21955 16213 15996 13564 9052 7701 7258 S calculation mm 20.337 15.897 11.921 9.215 6.349 5.681 5.486 S Actual mm 20.761 15.682 11.517 9.526 6.556 5.526 5.676

[0164] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0165] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 5.00 mm, and the actual thickness is 4.99 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0166] Example 5:

[0167] This example rolls 300 series stainless steel, coil number: 929656502, steel grade: 0CR18NI9DQ; the billet thickness is 180 mm, the billet width is 1020 mm, and the target thickness of rough rolling is 35 mm; the target thickness of the strip steel finished product is 3.5 mm, and the target width is 1034 mm.

[0168] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0169] 1. Load distribution for high-speed steel rolls

[0170] The load distribution (%) for each stand of this specification is: 64.7, 61.4, 53.1, 47.6, 38.0, 32.9, 23.0. According to Table 1, the load adjustment amounts (%) for F0 to F3 are +3, +3, +4, +4 respectively. After adjustment, the load distributions (%) for F0 to F3 are: F0: 64.7 * (1 + 3%) = 66.6; F1: 61.4 * (1 + 3%) = 63.2; F2: 53.1 * (1 + 4%) = 55.2; F3: 47.6 * (1 + 4%) = 49.5. After adjustment, the load distributions (%) for F0 to F6 are 66.6, 63.2, 55.2, 49.5, 38.0, 32.9, 23.0.

[0171] 2. Rolling pressure control for high-speed steel rolls

[0172] The calculation data of the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction EPS, work roll diameter (WRR), rolling speed (VU), pressure correction coefficient nnfk, etc. for each stand of this block of steel are as follows:

[0173] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 66.6 63.2 55.2 49.5 38.0 32.9 23.0 MH kN 52487 47244 44583 52032 54344 54215 63882 TE ℃ 1052.51 1047.23 1038.28 1030.42 1023.09 1014.97 1007.53 HE mm 35.73 21.776 13.699 9.265 6.578 5.112 4.126 EPS ％ 39.1 37.1 32.4 29.0 22.3 19.3 13.5 WHEN mm 1069 1069 1069 1069 1069 1069 1069 WRR mm 375.5 331.5 305.1 320.5 317.6 311.75 330 VU m / s 0.91 1.44 2.13 3.05 4.00 5.02 5.88 nnfk 0.95 0.856 0.932 0.852 0.833 0.91 0.874

[0174] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0175] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1052.51 - 1.52198 * 39.1% - 0.000095 * 375.5 - 0.12192 * 0.91 = 0.2112391

[0176] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1047.23 - 0.34882 * 37.1% - 0.001476 * 331.5 - 0.00283 * 1.44 = 0.1849743

[0177] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1038.28 - 0.9329 * 32.4% - 0.001742 * 305.1 - 0.02801 * 2.13 = 0.2557609

[0178] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1030.42 - 0.5923 * 29.0% - 0.001162 * 320.5 - 0.00581 * 3.05 = 0.1720328

[0179] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0180] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.95 * 52487 * 39.1% * (1.0 + 0.2112391) = 23614.7 (KN)

[0181] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.856 * 47244 * 37.1% * (1.0 + 0.1849743) = 17778.8 (KN)

[0182] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.932 * 44583 * 32.4% * (1.0 + 0.2557609) = 16905.9 (KN)

[0183] F(3) = nnfk3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.852 * 52032 * 29.0% * (1.0 + 0.1720328) = 15067.7 (KN)

[0184] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0185] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 23615 17779 16906 15068 10095 9522 7537 Factual kN 24105 18001 16035 14867 11054 10201 8001 S calculation mm 18.632 12.625 8.82 6.591 4.334 3.545 3.818 S Actual mm 18.356 12.311 8.91 6.753 4.002 3.269 3.627

[0186] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0187] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 3.50 mm, and the actual thickness is 3.48 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0188] Example 6:

[0189] This example rolls 300 series stainless steel, coil number: 929656703, steel grade: 0CR18NI9DQ; the billet thickness is 180 mm, the billet width is 1020 mm, and the target thickness for rough rolling is 35 mm; the target thickness of the finished strip is 2.5 mm, and the target width is 1034 mm.

[0190] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0191] 1. Load distribution for high-speed steel rolls

[0192] The load distribution (%) for each stand of this specification is: 69.1, 66.7, 54.0, 50.6, 38.9, 31.4, 24.7. According to Table 1, the load distribution is not adjusted.

[0193] 2. Rolling pressure control for high-speed steel rolls

[0194] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0195]

[0196]

[0197] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0198] coff_rolltype(0) = 0.6372 + 0.000300TE - 1.52198EPS - 0.000095WRR - 0.12192VU = 0.6372 + 0.000300 * 1043.07 - 1.52198 * 44.0% - 0.000095 * 375.5 - 0.12192 * 0.97 = 0.1265149

[0199] coff_rolltype(1) = 0.0349 + 0.000738TE - 0.34882EPS - 0.001476WRR - 0.00283VU = 0.0349 + 0.000738 * 1039.45 - 0.34882 * 43.0% - 0.001476 * 331.5 - 0.00283 * 1.70 = 0.1579165

[0200] coff_rolltype(2) = 0.7785 + 0.000357TE - 0.9329EPS - 0.001742WRR - 0.02801VU = 0.7785 + 0.000357 * 1033.84 - 0.9329 * 34.6% - 0.001742 * 305.1 - 0.02801 * 2.61 = 0.2202072

[0201] coff_rolltype(3) = 0.5835 + 0.000146TE - 0.5923EPS - 0.001162WRR - 0.00581VU = 0.5835 + 0.000146 * 1027.49 - 0.5923 * 32.4% - 0.001162 * 320.5 - 0.00581 * 3.86 = 0.1467607

[0202] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0203] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.926 * 56860 * 44.0% * (1.0 + 0.1265149) = 26098.0 (KN)

[0204] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.906 * 51182 * 43.0% * (1.0 + 0.1579165) = 23088.3 (KN)

[0205] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.917 * 48136 * 34.6% * (1.0 + 0.2202072) = 18635.8 (KN)

[0206] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.837 * 56223 * 32.4% * (1.0 + 0.1467607) = 17484.7 (KN)

[0207] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0208] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 26098 23088 18636 17485 11921 11005 9968 Factual kN 25931 23957 17980 16889 12034 11235 10037 S calculation mm 15.734 9.534 6.679 4.725 2.612 2.257 2.409 S Actual mm 15.968 9.356 6.935 4.897 2.357 2.038 2.259

[0209] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0210] In the actual application process, the rolling pressure control only needs to be accurate to 1 kN.

[0211] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.50 mm, the actual thickness is 2.49 mm, the rolling is stable, there is no overcurrent phenomenon, and it meets the rolling requirements.

[0212] Example 7:

[0213] This example rolls martensitic stainless steel, coil number: 929642701, steel grade: SUS420J2; the billet thickness is 200 mm, the billet width is 1244 mm, and the rough rolling target thickness is 35 mm; the target thickness of the strip steel finished product is 4.95 mm, and the target width is 1255 mm.

[0214] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0215] 1. Load distribution for high-speed steel rolls

[0216] The load distribution (%) for each stand of this specification is: 59.1, 56.3, 49.5, 44.8, 34.2, 27.2, 20.8. According to Table 1, the load distribution is not adjusted.

[0217] 2. Rolling pressure control for high-speed steel rolls

[0218] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction factor nnfk for each piece of steel are as follows:

[0219] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 59.1 56.3 49.5 44.8 34.2 27.2 20.8 MH kN 71306 63507 60684 69300 72489 71917 80754 TE ℃ 1049.75 1042.64 1034.43 1027.59 1020.88 1013.55 1006.82 HE mm 35.52 23.432 15.848 11.339 8.413 6.758 5.7 EPS ％ 34.0 32.4 28.5 25.8 19.7 15.6 12.0 WHEN mm 1290 1290 1290 1290 1290 1290 1290 WRR mm 374.45 336.7 314.2 315.4 321.6 307.25 326.75 VU m / s 1.04 1.54 2.16 2.94 3.74 4.5 5.12 nnfk 0.707 0.824 0.865 0.752 0.726 0.834 0.885

[0220] According to Table 2, the roll correction factors coff_rolltype for each stand are calculated as follows:

[0221] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1049.75 - 1.2367 * 34.0% - 0.000694 * 374.45 - 0.00966 * 1.04 = 0.3141993

[0222] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1042.64 + 0.5870 * 32.4% - 0.002427 * 336.7 - 0.08839 * 1.54 = 0.0609523

[0223] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1034.43 - 0.7436 * 28.5% - 0.001454 * 314.2 + 0.04064 * 2.16 = 0.2192759

[0224] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1027.59 - 0.8859 * 25.8% - 0.002126 * 315.4 + 0.01500 * 2.94 = 0.1407204

[0225] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0226] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.707 * 71306 * 34.0% * (1.0 + 0.3141993) = 22526.1 (KN)

[0227] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.824 * 63507 * 32.4% * (1.0 + 0.0609523) = 17988.3 (KN)

[0228] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.865 * 60684 * 28.5% * (1.0 + 0.2192759) = 18240.5 (KN)

[0229] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.752 * 69300 * 25.8% * (1.0 + 0.1407204) = 15337.3 (KN)

[0230] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0231] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 22526 17988 18241 15337 10368 9357 8576 Factual kN 23201 18034 18005 14896 9872 8976 8455 S calculation mm 21.279 15.498 11.321 8.829 6.716 5.999 5.426 S Actual mm 21.039 15.113 11.598 8.962 6.905 6.205 5.312

[0232] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0233] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 4.95 mm, and the actual thickness is 4.95 mm. The rolling is stable, without overcurrent phenomenon, meeting the rolling requirements.

[0234] Example 8:

[0235] This example involves rolling martensitic stainless steel with coil number: 929608701 and steel grade: SUS420J2; the billet thickness is 200mm, the billet width is 1240mm, and the rough rolling target thickness is 35mm; the target thickness of the finished strip is 4.00mm and the target width is 1265mm.

[0236] High-speed steel rolls are used for stands F0 - F3 of this piece of steel.

[0237] 1. Regarding the load distribution of high-speed steel rolls

[0238] The load distribution (%) of each stand for this specification is: 56.8, 54.7, 45.1, 41.3, 32.3, 27.2, 20.8. According to Table 1, the load adjustment amounts (%) for F0 - F3 are +3, +3, +4, +4 respectively. After adjustment, the load distributions (%) for F0 - F3 are: F0: 56.8 * (1 + 3%) = 58.5; F1: 54.7 * (1 + 3%) = 56.3; F2: 45.1 * (1 + 4%) = 46.9; F3: 41.3 * (1 + 4%) = 42.9. After adjustment, the load distribution (%) for F0 - F6 is 58.5, 56.3, 46.9, 42.9, 32.3, 27.2, 20.8.

[0239] 2. Regarding the rolling pressure control of high-speed steel rolls

[0240] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0241] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 58.5 56.3 46.9 42.9 32.3 27.2 20.8 MH kN 73192 65212 62361 71391 75240 75137 85145 TE ℃ 1048.18 1041.47 1034.37 1027.86 1021.33 1014.17 1007.66 HE mm 35.52 22.162 14.148 9.885 7.159 5.673 4.681 EPS ％ 37.6 36.2 30.1 27.6 20.8 17.5 13.4 WHEN mm 1300 1300 1300 1300 1300 1300 1300 WRR mm 374.45 336.7 314.2 315.4 321.6 307.25 326.75 VU m / s 1.02 1.60 2.30 3.21 4.15 5.09 5.90 nnfk 0.723 0.751 0.712 0.713 0.796 0.808 0.79

[0242] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0243] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1048.18 - 1.2367 * 37.6% - 0.000694 * 374.45 - 0.00966 * 1.02 = 0.2735891

[0244] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1041.47 + 0.5870 * 36.2% - 0.002427 * 336.7 - 0.08839 * 1.60 = 0.0796408

[0245] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1034.37 - 0.7436 * 30.1% - 0.001454 * 314.2 + 0.04064 * 2.30 = 0.2131865

[0246] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1027.86 - 0.8859 * 27.6% - 0.002126 * 315.4 + 0.01500 * 3.21 = 0.1284956

[0247] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0248] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.723 * 73192 * 37.6% * (1.0 + 0.2735891) = 25340.7 (KN)

[0249] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.751 * 65212 * 36.2% * (1.0 + 0.0796408) = 19140.6 (KN)

[0250] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.712 * 62361 * 30.1% * (1.0 + 0.2131865) = 16213.9 (KN)

[0251] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.713 * 71391 * 27.6% * (1.0 + 0.1284956) = 15854.1 (KN)

[0252] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0253] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 25341 19141 16214 15854 12457 10624 9013 Factual kN 25413 18936 17129 15393 12439 10932 9817 S calculation mm 19.497 13.091 9.428 7.196 5.231 4.472 4.067 S Actual mm 19.601 13.284 9.016 7.352 5.157 4.529 4.253

[0254] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0255] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 4.00 mm, and the actual thickness is 3.99 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0256] Example 9:

[0257] In this example, martensitic stainless steel is rolled. The coil number is 929608902, and the steel grade is SUS420J2; the billet thickness is 200 mm, the billet width is 1240 mm, and the target thickness of rough rolling is 35 mm; the target thickness of the finished strip is 2.975 mm, and the target width is 1265 mm.

[0258] High-speed steel rolls are used for F0 - F3 of this piece of steel.

[0259] 1. Load distribution for high-speed steel rolls

[0260] The load distribution (%) for each stand of this specification is: 65.0, 56.3, 46.9, 42.9, 34.2, 28.8, 20.8. According to Table 1, the load distribution is not adjusted.

[0261] 2. Rolling pressure control for high-speed steel rolls

[0262] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0263] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 65.0 56.3 46.9 42.9 34.2 28.8 20.8 MH kN 68889 61561 59849 69194 74267 75307 87927 TE ℃ 1063.53 1055.41 1045.1 1036.2 1027.08 1017.88 1009.24 HE mm 35.529 19.631 12.03 8.148 5.742 4.39 3.52 EPS ％ 44.7 38.7 32.3 29.5 23.5 19.8 14.3 WHEN mm 1300 1300 1300 1300 1300 1300 1300 WRR mm 374.45 336.7 314.2 315.4 321.6 307.25 326.75 VU m / s 0.98 1.61 2.39 3.42 4.57 5.78 6.8 nnfk 0.854 0.806 0.816 0.762 0.858 0.945 1.033

[0264] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0265] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1063.53 - 1.2367 * 44.7% - 0.000694 * 374.45 - 0.00966 * 0.98 = 0.149821

[0266] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1055.41 + 0.5870 * 38.7% - 0.002427 * 336.7 - 0.08839 * 1.61 = 0.073344

[0267] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1045.1 - 0.7436 * 32.3% - 0.001454 * 314.2 + 0.04064 * 2.39 = 0.179282

[0268] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1036.2 - 0.8859 * 29.5% - 0.002126 * 315.4 + 0.01500 * 3.42 = 0.104664

[0269] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0270] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.854 * 68889 * 44.7% * (1.0 + 0.149821) = 30237.5 (KN)

[0271] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.806 * 61561 * 38.7% * (1.0 + 0.073344) = 20610.6 (KN)

[0272] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.816 * 59849 * 32.3% * (1.0 + 0.179282) = 18602.3 (KN)

[0273] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.762 * 69194 * 29.5% * (1.0 + 0.104664) = 17182.1 (KN)

[0274] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0275] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 30237 20611 18602 17182 14974 14091 12988 Factual kN 30941 19926 18650 16595 15000 14112 13002 S calculation mm 15.857 10.575 7.316 5.488 3.384 2.811 2.549 S Actual mm 15.569 10.771 7.305 5.638 3.352 2.79 2.346

[0276] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0277] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.975 mm, the actual thickness is 2.981 mm, the rolling is stable, there is no overcurrent phenomenon, and the rolling requirements are met.

[0278] Example 10:

[0279] This example rolls martensitic stainless steel, coil number: 929711501, steel grade: 30CR13; blank thickness 200 mm, blank width 1020 mm, rough rolling target thickness 35 mm; strip finished product target thickness 4.80 mm, target width 1035 mm.

[0280] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0281] 1. Load distribution for high-speed steel rolls

[0282] The load distribution (%) for each stand of this specification is: 61.7, 58.5, 49.5, 44.8, 34.2, 27.2, 19.5. According to Table 1, the load distribution is not adjusted.

[0283] 2. Rolling pressure control for high-speed steel rolls

[0284] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0285] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 61.7 58.5 49.5 44.8 34.2 27.2 19.5 MH kN 58022 52220 50310 57991 61158 61206 69052 TE ℃ 1069.53 1058.91 1047.96 1038.13 1028.76 1018.95 1009.91 HE mm 35.53 22.921 15.215 10.891 8.084 6.495 5.48 EPS ％ 35.5 33.6 28.4 25.8 19.7 15.6 11.2 WHEN mm 1070 1070 1070 1070 1070 1070 1070 WRR mm 377.6 315 312.5 305.5 313.5 308.5 330.15 VU m / s 1.06 1.59 2.24 3.05 3.88 4.66 5.28 nnfk 0.718 0.704 0.751 0.72 0.728 0.843 0.863

[0286] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0287] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1069.53 - 1.2367 * 35.5% - 0.000694 * 377.6 - 0.00966 * 1.06 = 0.24643

[0288] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1058.91 + 0.5870 * 33.6% - 0.002427 * 315 - 0.08839 * 1.59 = 0.092798

[0289] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1047.96 - 0.7436 * 28.4% - 0.001454 * 312.5 + 0.04064 * 2.24 = 0.199007

[0290] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1038.13 - 0.8859 * 25.8% - 0.002126 * 305.5 + 0.01500 * 3.05 = 0.150591

[0291] According to formula (3), the rolling forces F0 to F3 are calculated as follows:

[0292] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.718 * 58022 * 35.5% * (1.0 + 0.24643) = 18433.7 (KN)

[0293] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.704 * 52220 * 33.6% * (1.0 + 0.092798) = 13498.6 (KN)

[0294] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.751 * 50310 * 28.4% * (1.0 + 0.199007) = 12865.7 (KN)

[0295] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.72 * 57991 * 25.8% * (1.0 + 0.150591) = 12394.6 (KN)

[0296] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0297] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 18434 13499 12866 12395 8771 8049 6674 Factual kN 17863 12888 12171 11216 8753 8066 6679 S calculation mm 21.208 14.995 11.134 8.693 6.631 5.947 5.598 S Actual mm 21.694 15.167 11.358 8.864 6.655 6.003 5.587

[0298] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0299] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 4.80 mm, the actual thickness is 4.80 mm, the rolling is stable, there is no overcurrent phenomenon, and it meets the rolling requirements.

[0300] Example 11:

[0301] This example rolls martensitic stainless steel, coil number: 929711702, steel grade: 30CR13; the blank thickness is 200 mm, the blank width is 1023 mm, and the rough rolling target thickness is 35 mm; the target thickness of the finished strip is 3.5 mm, and the target width is 1035 mm.

[0302] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0303] 1. Load distribution for high-speed steel rolls

[0304] The load distribution (%) for each stand of this specification is: 59.9, 54.7, 49.6, 41.3, 32.3, 27.2, 20.8. According to Table 1, the load adjustment amounts (%) for F0 to F3 are +3, +3, +4, +4 respectively. After adjustment, the load distributions (%) for F0 to F3 are: F0: 59.9 * (1 + 3%) = 61.7; F1: 54.7 * (1 + 3%) = 56.3; F2: 49.6 * (1 + 4%) = 51.6; F3: 41.3 * (1 + 4%) = 42.9. After adjustment, the load distributions (%) for F0 to F6 are 61.7, 56.3, 51.6, 42.9, 32.3, 25.6, 19.5.

[0305] 2. Rolling pressure control for high-speed steel rolls

[0306] The calculation data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk of each stand of this block of steel are as follows:

[0307] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 61.7 56.3 51.6 42.9 32.3 25.6 19.5 MH kN 59560 53230 51355 59092 62727 63156 72431 TE ℃ 1057.27 1049.5 1040.7 1034.27 1026.52 1017.81 1009.31 HE mm 35.525 21.023 13.206 8.701 6.234 4.903 4.073 EPS ％ 40.8 37.2 34.1 28.4 21.4 16.9 12.9 WHEN mm 1060.66 1060.66 1060.66 1060.66 1060.66 1060.66 1060.66 WRR mm 377.6 315 312.5 305.5 313.5 308.5 330.15 VU m / s 1.05 1.67 2.53 3.59 4.68 5.71 6.59 nnfk 0.79 0.764 0.81 0.715 0.818 0.914 0.961

[0308] According to Table 2, the roll correction coefficients coff_rolltype of each stand are calculated as follows:

[0309] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1057.27 - 1.2367 * 40.8% - 0.000694 * 377.6 - 0.00966 * 1.05 = 0.210014

[0310] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1049.5 + 0.5870 * 37.2% - 0.002427 * 315 - 0.08839 * 1.67 = 0.120418

[0311] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1040.7 - 0.7436 * 34.1% - 0.001454 * 312.5 + 0.04064 * 2.53 = 0.182753

[0312] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1034.27 - 0.8859 * 28.4% - 0.002126 * 305.5 + 0.01500 * 3.59 = 0.140355

[0313] According to formula (3), the rolling pressures of F0 to F3 are calculated as follows:

[0314] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.79 * 59560 * 40.8% * (1.0 + 0.210014) = 23229.1 (KN)

[0315] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.764 * 53230 * 37.2% * (1.0 + 0.120418) = 16950.1 (KN)

[0316] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.81 * 51355 * 34.1% * (1.0 + 0.182753) = 16777.1 (KN)

[0317] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.715 * 59092 * 28.4% * (1.0 + 0.140355) = 13683.4 (KN)

[0318] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0319] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 23229 16950 16777 13683 10980 9755 8979 Factual kN 22865 16114 16817 13661 10951 9769 8969 S calculation mm 18.665 12.466 8.14 6.41 4.642 4.266 3.881 S Actual mm 18.935 12.611 8.023 6.421 4.633 4.277 3.866

[0320] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0321] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 3.50 mm, and the actual thickness is 3.51 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0322] Example 12:

[0323] This example rolls martensitic stainless steel, coil number: 929711902, steel grade: 30CR13; the billet thickness is 200 mm, the billet width is 1026 mm, and the rough rolling target thickness is 35 mm; the target thickness of the strip steel finished product is 2.8 mm, and the target width is 1035 mm.

[0324] High-speed steel rolls are used for F0 to F3 of this piece of steel.

[0325] 1. Load distribution for high-speed steel rolls

[0326] The load distribution (%) for each stand of this specification is: 65.0, 56.3, 51.6, 46.8, 32.3, 27.2, 18.7. According to Table 1, the load distribution is not adjusted.

[0327] 2. Rolling pressure control for high-speed steel rolls

[0328] The calculation data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each piece of steel are as follows:

[0329] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 65 56.3 51.6 46.8 32.3 27.2 18.7 MH kN 59681 53128 51608 59452 63816 64952 75504 TE ℃ 1055.53 1049.01 1040 1034.07 1027.09 1018.02 1009.44 HE mm 35.525 19.53 11.92 7.66 5.177 4.018 3.261 EPS ％ 45.0 39.0 35.7 32.4 22.4 18.8 13.0 WHEN mm 1060.66 1060.66 1060.66 1060.66 1060.66 1060.66 1060.66 WRR mm 377.6 315 312.5 305.5 313.5 308.5 330.15 VU m / s 1.01 1.66 2.58 3.86 5.12 6.39 7.41 nnfk 0.884 0.829 0.815 0.756 0.851 0.946 0.985

[0330] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0331] coff_rolltype(0) = 3.4904 - 0.002368TE - 1.2367EPS - 0.000694WRR - 0.00966VU = 3.4904 - 0.002368 * 1055.53 - 1.2367 * 45.0% - 0.000694 * 377.6 - 0.00966 * 1.01 = 0.162579

[0332] coff_rolltype(1) = 2.3265 - 0.001441TE + 0.5870EPS - 0.002427WRR - 0.08839VU = 2.3265 - 0.001441 * 1049.01 + 0.5870 * 39.0% - 0.002427 * 315 - 0.08839 * 1.66 = 0.132574

[0333] coff_rolltype(2) = 2.8443 - 0.001976TE - 0.7436EPS - 0.001454WRR + 0.04064VU = 2.8443 - 0.001976 * 1040 - 0.7436 * 35.7% - 0.001454 * 312.5 + 0.04064 * 2.58 = 0.174271

[0334] coff_rolltype(3) = 2.2463 - 0.001217TE - 0.8859EPS - 0.002126WRR + 0.01500VU = 2.2463 - 0.001217 * 1034.07 - 0.8859 * 32.4% - 0.002126 * 305.5 + 0.01500 * 3.86 = 0.109212

[0335] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0336] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.884 * 59681 * 45.0% * (1.0 + 0.162579) = 27600.9 (KN)

[0337] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.829 * 53128 * 39.0% * (1.0 + 0.132574) = 19454 (KN)

[0338] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.815 * 51608 * 35.7% * (1.0 + 0.174271) = 17632.4 (KN)

[0339] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.756 * 59452 * 32.4% * (1.0 + 0.109212) = 16152.8 (KN)

[0340] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0341] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 27601 19454 17632 16153 12165 11552 9668 Factual kN 26447 18156 18355 15920 11065 11578 9639 S calculation mm 16.696 11.008 6.836 4.938 3.52 3.099 3.055 S Actual mm 16.897 11.235 6.539 4.776 3.684 3.075 3.048

[0342] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0343] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.80 mm, and the actual thickness is 2.81 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0344] Example 13:

[0345] This example rolls high-grade silicon steel, coil number: 929436101, steel type: DV19; the billet thickness is 220 mm, the billet width is 1270 mm, and the target thickness of rough rolling is 40 mm; the target thickness of the strip steel finished product is 2.25 mm, and the target width is 1265 mm.

[0346] The F2 stand of this piece of steel uses high-speed steel rolls.

[0347] 1. Load distribution for high-speed steel rolls

[0348] The load distribution (%) of each stand in this specification is: 55.7, 44.4, 37.2, 31.4, 24.0, 21.6, 15.4. According to Table 1, the load adjustment amount (%) of F2 is +5, and the load distribution (%) of F2 after adjustment is: 37.2 * (1 + 5%) = 39.1. The load distribution (%) of F0 - F6 after adjustment is 55.7, 44.4, 39.1, 31.4, 24.0, 21.6, 15.4.

[0349] 2. Rolling pressure control for high - speed steel rolls

[0350] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction EPS, work roll diameter (WRR), rolling speed (VU), pressure correction coefficient nnfk, etc. of each piece of steel are as follows:

[0351]

[0352]

[0353] According to Table 2, the roll correction coefficient coff_rolltype of the F2 stand is calculated as follows:

[0354] coff_rolltype(2) = 1.0676 - 0.000307TE + 0.1744EPS - 0.001063WRR - 0.11970VU = 1.0676 - 0.000307 * 912.23 + 0.1744 * 38.0% - 0.001063 * 311.8 - 0.11970 * 3.05 = 0.15729

[0355] According to formula (3), the rolling pressure of F2 is calculated as follows:

[0356] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.918 * 40111 * 38.0% * (1.0 + 0.15729) = 16193.2 (KN)

[0357] The calculated and actual values of the rolling pressure and roll gap of each stand are as follows:

[0358] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 18348 13767 16193 14534 13524 12996 12447 Factual kN 18804 13950 16410 15070 13949 13424 12924 S calculation mm 16.171 9.848 6.038 4.284 2.332 1.87 1.565 S Actual mm 15.938 9.745 5.991 4.405 2.119 1.697 1.431

[0359] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0360] The deviation of the rolling pressure of each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.25 mm, and the actual thickness is 2.22 mm. The rolling is stable, without over - current phenomenon, meeting the rolling requirements.

[0361] Example 14:

[0362] In this example, high-grade silicon steel was rolled. The coil number was 929436401, and the steel grade was DV19A. The billet thickness was 220 mm, the billet width was 1175 mm, and the target thickness after rough rolling was 40 mm. The target thickness of the finished strip was 2.20 mm, and the target width was 1170 mm.

[0363] High-speed steel rolls were used for stand F2 of this piece of steel.

[0364] 1. Load distribution for high-speed steel rolls

[0365] The load distribution (%) for each stand of this specification was: 60.0, 48.1, 38.1, 33.0, 24.0, 21.6, 15.4. According to Table 1, the load adjustment amount (%) for F2 was +7. After adjustment, the load distribution (%) for F2 was: 38.1*(1 + 7%) = 40.8. After adjustment, the load distribution (%) for F0 - F6 was 60.0, 48.1, 40.8, 33.0, 24.0, 21.6, 15.4.

[0366] 2. Rolling pressure control for high-speed steel rolls

[0367] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel were as follows:

[0368] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 60.0 48.1 40.8 33.0 24.0 21.6 15.4 MH kN 42623 37340 37510 43991 48893 49996 62509 TE ℃ 936.59 922.88 909.98 899.41 889.16 869.82 849.8 HE mm 40.646 18.291 9.967 6.165 4.24 3.278 2.61 EPS ％ 55 45.5 38.1 31.2 22.7 20.4 14.5 WHEN mm 1205 1205 1205 1205 1205 1205 1205 WRR mm 369.6 324.75 311.8 312.35 319.1 301.9 330.9 VU m / s 1.06 1.93 3.1 4.57 6.05 7.64 9.06 nnfk 0.729 0.782 0.954 0.995 1.098 1.153 1.135

[0369] According to Table 2, the roll correction coefficient coff rolltype for stand F2 was calculated as follows:

[0370] coff_rolltype(2) = 1.0676 - 0.000307TE + 0.1744EPS - 0.001063WRR - 0.11970VU = 1.0676 - 0.000307*909.98 + 0.1744*38.1% - 0.001063*311.8 - 0.11970*3.1 = 0.15217

[0371] According to formula (3), the rolling pressure for F2 was calculated as follows:

[0372] F(2) = nnfk(2)*MH(2)*EPS(2)*(1.0 + coff_rolltype(2)) = 0.954*37510*38.1%*(1.0 + 0.15217) = 15708.6 (KN)

[0373] The calculated and actual rolling pressures and roll gaps of each stand are as follows:

[0374] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 17090 13286 15709 13657 12186 11760 10287 Factual kN 17333 14030 15498 14185 12575 12170 11061 S calculation mm 16.43 9.434 6.076 4.059 2.294 1.802 1.63 S Actual mm 16.202 9.213 6.125 3.882 2.136 1.715 1.486

[0375] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0376] The deviation of the rolling pressure of each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.20 mm, the actual thickness is 2.19 mm, the rolling is stable, there is no overcurrent phenomenon, and the rolling requirements are met.

[0377] Example 15:

[0378] This example rolls low-grade silicon steel, coil number: 929506701, steel type: DW60B; blank thickness 222 mm, blank width 1035 mm, rough rolling target thickness 47 mm; strip finished product target thickness 2.60 mm, target width 1020 mm.

[0379] High-speed steel rolls are used for F0 - F2 of this piece of steel.

[0380] 1. Load distribution for high-speed steel rolls

[0381] The load distribution (%) of each stand for this specification is: 69, 49, 45, 41, 37, 31, 28. According to Table 1, the load distribution is not adjusted.

[0382] 2. Rolling pressure control for high-speed steel rolls

[0383] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), pressure correction coefficient nnfk, etc. of each stand for this piece of steel are as follows:

[0384] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 57 51.8 44 37 28 22 15 MH kN 34649 29278 28506 33262 33885 33690 38927 TE ℃ 939.59 930.49 921.08 911.83 903.59 896.45 888.97 HE mm 47.762 23.266 12.46 7.593 5.069 3.78 3.043 EPS ％ 51.3 46.4 39.1 33.2 25.4 19.5 13.3 WHEN mm 1055.58 1055.58 1055.58 1055.58 1055.58 1055.58 1055.58 WRR mm 375.35 330.2 315.5 319.75 314.05 302.4 329.15 VU m / s 0.95 1.77 2.88 4.33 5.91 7.42 8.7 nnfk 0.799 0.691 0.689 0.691 0.769 0.788 0.853

[0385] According to Table 2, the roll correction coefficients coff_rolltype of each stand are calculated as follows:

[0386] coff_rolltype(0) = -2.1325 + 0.003794TE - 1.1830EPS - 0.001407WRR + 0.01032VU = -2.1325 + 0.003794 * 939.59 - 1.1830 * 51.3% - 0.001407 * 375.35 + 0.01032 * 0.95 = 0.307112

[0387] coff_rolltype(1) = 0.8538 - 0.000962TE + 0.5999EPS - 0.000569WRR + 0.08931VU = 0.8538 - 0.000962 * 930.49 + 0.5999 * 46.4% - 0.000569 * 330.2 + 0.08931 * 1.77 = 0.2072171

[0388] coff_rolltype(2) = 3.903 - 0.000625TE - 1.190EPS - 0.00913WRR + 0.0590VU = 3.903 - 0.000625 * 921.08 - 1.190 * 39.1% - 0.00913 * 315.5 + 0.0590 * 2.88 = 0.15144

[0389] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0390] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.799 * 34649 * 51.3% * (1.0 + 0.307112) = 18563.83 (KN)

[0391] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.691 * 29278 * 46.4% * (1.0 + 0.2072171) = 11332.42 (KN)

[0392] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.689 * 28506 * 39.1% * (1.0 + 0.15144) = 8842.47 (KN)

[0393] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0394] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 18564 11332 8842 7631 6619 5177 4416 Factual kN 18714 10782 8355 8001 6679 5268 4520 S calculation mm 21.253 12.695 8.91 6.658 4.16 3.864 3.591 S Actual mm 21.229 12.568 8.905 6.608 3.995 3.829 3.513

[0395] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0396] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.60 mm, and the actual thickness is 2.59 mm. The rolling is stable and there is no overcurrent phenomenon, meeting the rolling requirements.

[0397] Example 16:

[0398] This example involves rolling carbon steel. Coil number: 929067701, steel type: Q195-W; blank thickness 222mm, blank width 1233mm, rough rolling target thickness 40mm; strip finished product target thickness 4.50mm, target width 1250mm.

[0399] For this piece of steel, high-speed steel rolls are used from F0 to F3.

[0400] 1. Regarding the load distribution of high-speed steel rolls

[0401] The load distribution (%) of each stand for this specification is: 60.0, 54.6, 47.0, 43.0, 36.1, 30.4, 27.0. According to Table 1, the load distribution is not adjusted.

[0402] 2. Regarding the rolling pressure control of high-speed steel rolls

[0403] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0404] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 60 54.6 47 43 36.1 30.4 27 MH kN 33145 31039 29674 34702 37514 38536 43579 TE ℃ 1024.86 1003.16 984.66 966.95 949.33 928.45 914.71 HE mm 40.775 25.545 16.862 11.928 8.735 6.772 5.491 EPS ％ 37.4 34 29.3 26.8 22.5 18.9 16.8 WHEN mm 1283 1283 1283 1283 1283 1283 1283 WRR mm 370.35 338.9 311.1 313.1 322.5 310.6 336.5 VU m / s 0.96 1.46 2.07 2.86 3.73 4.64 5.57 nnfk 1.01 1.037 1.079 1.015 1.058 1.164 0.89

[0405] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0406] coff_rolltype(0) = -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686 * 1024.86 - 1.1344 * 37.4% - 0.001220 * 370.35 + 0.06146 * 0.96 = 0.36202

[0407] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 1003.16 + 0.3495 * 34% + 0.000441 * 338.9 + 0.03720 * 1.46 = 0.1941257

[0408] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 984.66 + 0.2734 * 29.3% - 0.001253 * 311.1 + 0.07869 * 2.07 = 0.2622688

[0409] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 966.95 - 0.2271 * 26.8% - 0.000989 * 313.1 + 0.04831 * 2.86 = 0.2044634

[0410] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0411] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.01 * 33145 * 37.4% * (1.0 + 0.36202) = 17052.75 (KN)

[0412] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 1.037 * 31039 * 34% * (1.0 + 0.1941257) = 13068.19 (KN)

[0413] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 1.079 * 29674 * 29.3% * (1.0 + 0.2622688) = 11841.78 (KN)

[0414] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 1.015 * 34702 * 26.8% * (1.0 + 0.2044634) = 11369.70 (KN)

[0415] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0416] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 17053 13068 11842 11370 8930 8478 6516 Factual kN 17314 12782 11355 10901 8897 8268 6521 S calculation mm 24.256 17.077 12.904 9.823 6.841 5.691 5.13 S Actual mm 23.229 17.098 12.905 9.698 6.995 5.723 5.117

[0417] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0418] The rolling pressure deviation of each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 4.50 mm, and the actual thickness is 4.53 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0419] Example 17:

[0420] This example rolls carbon steel. Coil number: 929067902, steel grade: Q195-W; billet thickness 222 mm, billet width 1230 mm, rough rolling target thickness 40 mm; strip finished product target thickness 3.0 mm, target width 1215 mm.

[0421] High-speed steel rolls are used for stands F0 - F3 of this piece of steel.

[0422] 1. Load distribution for high-speed steel rolls

[0423] The load distribution (%) of each stand for this specification is: 64.4, 51, 45.8, 36.2, 31.5, 27.2, 25. According to Table 1, the load adjustment amounts (%) for F0 - F3 are +4, +4, +5, +5 respectively. After adjustment, the load distributions (%) for F0 - F3 are: F0: 64.4*(1 + 4%) = 67.0; F1: 51*(1 + 4%) = 53.0; F2: 45.8*(1 + 5%) = 48.1; F3: 36.2*(1 + 5%) = 38.0. After adjustment, the load distribution (%) for F0 - F6 is 67.0, 53.0, 48.1, 38.0, 31.5, 27.2, 25.0.

[0424] 2. Rolling pressure control for high-speed steel rolls

[0425] The calculation data such as load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction ratio EPS, work roll diameter (WRR), rolling speed (VU), pressure correction coefficient nnfk, etc. for each stand of this piece of steel are as follows:

[0426] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 67.0 53.0 48.1 38.0 31.5 27.2 25 MH kN 33041 30826 29618 34746 37593 38787 44287 TE ℃ 1017.05 995.93 978.83 963.01 946.44 926.13 913.08 HE mm 40.771 20.871 12.813 8.333 6.026 4.643 3.723 EPS ％ 48.8 38.6 35 27.7 22.9 19.8 18.2 WHEN mm 1252.67 1252.67 1252.67 1252.67 1252.67 1252.67 1252.67 WRR mm 370.35 338.9 311.1 313.1 322.5 310.6 336.5 VU m / s 1.07 1.75 2.69 3.79 4.97 6.22 7.64 nnfk 1.079 1.134 1.174 0.944 1.085 1.154 0.963

[0427] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0428] coff_rolltype(0)= -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686*1017.05 - 1.1344*48.8% - 0.001220*370.35 + 0.06146*1.07 = 0.2262943

[0429] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 995.93 + 0.3495 * 38.6% + 0.000441 * 338.9 + 0.03720 * 1.75 = 0.2124593

[0430] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 978.83 + 0.2734 * 35% - 0.001253 * 311.1 + 0.07869 * 2.69 = 0.3178546

[0431] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 963.01 - 0.2271 * 27.7% - 0.000989 * 313.1 + 0.04831 * 3.79 = 0.2424976

[0432] According to formula (3), the rolling pressures of F0 to F3 are calculated as follows:

[0433] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.079 * 33041 * 48.8% * (1.0 + 0.2262943) = 21334.8 (KN)

[0434] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 1.134 * 30826 * 38.6% * (1.0 + 0.2124593) = 16360.1 (KN)

[0435] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 1.174 * 29618 * 35% * (1.0 + 0.3178546) = 16038.3 (KN)

[0436] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.944 * 34746 * 27.7% * (1.0 + 0.2424976) = 11369.70 (KN)

[0437] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0438] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 21335 16360 16038 11289 9341 8863 7762 Factual kN 22032 16355 15961 10997 9807 8763 7539 S calculation mm 19.271 12.822 8.963 7.019 4.704 3.883 3.422 S Actual mm 19.025 12.953 9.097 7.033 4.682 3.901 3.458

[0439] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0440] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 3.0 mm, the actual thickness is 3.03 mm, the rolling is stable, there is no overcurrent phenomenon, and the rolling requirements are met.

[0441] Example 18:

[0442] In this example, carbon steel is rolled. The coil number is 929068103, and the steel grade is Q195 - W; the billet thickness is 222 mm, the billet width is 1230 mm, and the target thickness for rough rolling is 40 mm; the target thickness of the finished strip is 1.48 mm, and the target width is 1215 mm.

[0443] High - speed steel rolls are used for F0 - F3 of this piece of steel.

[0444] 1. Load distribution for high - speed steel rolls

[0445] The load distribution (%) for each stand of this specification is: 59.7, 53.4, 47.0, 41.7, 31.5, 26.1, 18.7. According to Table 1, the load adjustment amounts (%) for F0 - F3 are +3, +3, +3, +3 respectively. After adjustment, the load distributions (%) for F0 - F3 are: F0: 59.7 * (1 + 3%) = 61.5; F1: 53.4 * (1 + 3%) = 55.0; F2: 47.0 * (1 + 3%) = 48.4; F3: 41.7 * (1 + 3%) = 42.9. After adjustment, the load distributions (%) for F0 - F6 are 61.5, 55.0, 48.4, 42.9, 31.5, 26.1, 18.7.

[0446] 2. Rolling pressure control for high - speed steel rolls

[0447] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (VU), and pressure correction coefficient nnfk for each stand of this piece of steel are as follows:

[0448]

[0449]

[0450] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0451] coff_rolltype(0) = -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686 * 1021.49 - 1.1344 * 54.9% - 0.001220 * 377.5 + 0.06146 * 0.71 = 0.1337331

[0452] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 988.52 + 0.3495 * 49.1% + 0.000441 * 330.3 + 0.03720 * 1.39 = 0.2232284

[0453] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 960.18 + 0.2734 * 43.2% - 0.001253 * 314.6 + 0.07869 * 2.47 = 0.2904706

[0454] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 936.07 - 0.2271 * 38.3% - 0.000989 * 311.45 + 0.04831 * 4.06 = 0.1999374

[0455] According to formula (3), the rolling forces F0 to F3 are calculated as follows:

[0456] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.924 * 32495 * 54.9% * (1.0 + 0.1337331) = 18688.4 (KN)

[0457] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 1.003 * 29723 * 49.1% * (1.0 + 0.2232284) = 17905.3 (KN)

[0458] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 1.049 * 30772 * 43.2% * (1.0 + 0.2904706) = 17995.5 (KN)

[0459] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.916 * 36420 * 38.3% * (1.0 + 0.1999374) = 15331.8 (KN)

[0460] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0461] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 18688 17905 17995 15332 11601 10824 9680 Factual kN 18011 17325 18002 14991 11023 9926 9534 S calculation mm 16.101 8.871 5.138 3.863 2.118 1.758 1.689 S Actual mm 16.211 8.900 5.116 3.801 2.199 1.801 1.700

[0462] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0463] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this slab is 1.48 mm, and the actual thickness is 1.49 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0464] Example 19:

[0465] This example rolls carbon steel grade, coil number: 929099101, steel grade: Q235B; billet thickness 230 mm, billet width 1060 mm, rough rolling target thickness 40 mm; strip finished product target thickness 3.80 mm, target width 1050 mm.

[0466] For this slab, high-speed steel rolls are used for F0 to F3.

[0467] 1. Load distribution for high-speed steel rolls

[0468] The load distribution (%) for each stand of this specification is: 70.4, 55.6, 50.4, 43.7, 29.7, 25.6, 25.0. According to Table 1, the load distribution is not adjusted.

[0469] 2. Rolling pressure control for high-speed steel rolls

[0470] The calculation data of the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction EPS, work roll diameter (WRR), rolling speed (VU), pressure correction coefficient nnfk, etc. for each stand of this block of steel are as follows:

[0471] item unit F0 F1 F2 F3 F4 F5 F6 LV ％ 70.4 55.6 50.4 43.7 29.7 25.6 25 MH kN 32277 30426 29619 35235 38718 40267 46762 TE ℃ 1050.21 1025.61 1001.73 979.94 959.37 933.83 919.11 HE mm 40.807 22.186 14.177 9.542 6.837 5.518 4.602 EPS ％ 45.6 36.1 32.7 28.3 19.3 16.6 16.2 WHEN mm 1085 1085 1085 1085 1085 1085 1085 WRR mm 370.35 338.9 311.1 313.1 322.5 310.6 336.5 VU m / s 0.72 1.13 1.69 2.38 3.01 3.62 4.33 nnfk 0.932 0.91 0.937 0.804 0.955 1.031 1.055

[0472] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0473] coff_rolltype(0) = -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686 * 1050.21 - 1.1344 * 45.6% - 0.001220 * 370.35 + 0.06146 * 0.72 = 0.2969919

[0474] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 1025.61 + 0.3495 * 36.1% + 0.000441 * 338.9 + 0.03720 * 1.13 = 0.2156802

[0475] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 1001.73 + 0.2734 * 32.7% - 0.001253 * 311.1 + 0.07869 * 1.69 = 0.2673867

[0476] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 979.94 - 0.2271 * 28.3% - 0.000989 * 313.1 + 0.04831 * 2.38 = 0.19386

[0477] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0478] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 0.932 * 32277 * 45.6% * (1.0 + 0.2969919) = 17791.4 (KN)

[0479] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 0.91 * 30426 * 36.1% * (1.0 + 0.2156802) = 12151.0 (KN)

[0480] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 0.937 * 29619 * 32.7% * (1.0 + 0.2673867) = 11501.8 (KN)

[0481] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.804 * 35235 * 28.3% * (1.0 + 0.19386) = 9571.3 (KN)

[0482] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0483] unit F0 F1 F2 F3 F4 F5 F6 F calculation kN 17791 12151 11502 9571 7136 6892 7992 Factual kN 18052 11327 10991 10002 7253 6885 8007 Calculated S mm 21.155 14.988 10.927 8.086 5.886 5.012 4.051 Actual S mm 20.297 14.997 11.001 7.992 5.793 5.109 4.012

[0484] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0485] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 3.80 mm, the actual thickness is 3.78 mm, the rolling is stable, there is no overcurrent phenomenon, and the rolling requirements are met.

[0486] Example 20:

[0487] In this example, carbon steel is rolled. Coil number: 929099302, steel grade: Q235B; billet thickness 230 mm, billet width 1060 mm, rough rolling target thickness 40 mm; finished strip target thickness 2.01 mm, target width 1050 mm.

[0488] High-speed steel rolls are used for F0 - F3 of this piece of steel.

[0489] 1. Load distribution for high-speed steel rolls

[0490] The load distribution (%) of each stand in this specification is: 63.8, 55.5, 50.3, 43.4, 31.5, 28.8, 21.3. According to Table 1, the load adjustment amounts (%) of F0 to F3 are +5, +5, +5, +5 respectively. After adjustment, the load distributions (%) of F0 to F3 are: F0: 63.8 * (1 + 5%) = 67.0; F1: 55.5 * (1 + 5%) = 58.3; F2: 50.3 * (1 + 5%) = 52.8; F3: 43.4 * (1 + 5%) = 45.6. After adjustment, the load distributions (%) of F0 to F6 are 67.0, 58.3, 52.8, 45.6, 31.5, 28.8, 21.3.

[0491] 2. Rolling pressure control for high-speed steel rolls

[0492] The calculated data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (31.5, 28.8, 21.3U), pressure correction coefficient nnfk, etc. for each piece of steel are as follows:

[0493] Item Unit F0 F1 F2 F3 F4 F5 F6 LV ％ 67.0 58.3 52.8 45.6 31.5 28.8 21.3 MH kN 36534 32204 32326 37729 43133 44166 51734 TE ℃ 1010.4 994.06 977.5 962.39 947.29 922.93 911.55 HE mm 40.762 19.669 10.813 6.403 4.148 3.139 2.441 EPS ％ 51.7 45 40.8 35.2 24.3 22.2 16.4 WHEN mm 1082 1082 1082 1082 1082 1082 1082 WRR mm 377.5 330.3 314.6 311.45 320.6 308.2 330 VU m / s 0.85 1.54 2.6 4.05 5.48 7.06 8.57 nnfk 1.095 1.048 1.08 1.004 1.1 1.153 1.121

[0494] According to Table 2, the roll correction coefficients coff_rolltype for each stand are calculated as follows:

[0495] coff_rolltype(0) = -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686 * 1010.4 - 1.1344 * 51.7% - 0.001220 * 377.5 + 0.06146 * 0.85 = 0.15994

[0496] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 994.06 + 0.3495 * 45% + 0.000441 * 330.3 + 0.03720 * 1.54 = 0.22102

[0497] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 977.5 + 0.2734 * 40.8% - 0.001253 * 314.6 + 0.07869 * 2.6 = 0.32024

[0498] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 962.39 - 0.2271 * 35.2% - 0.000989 * 311.45 + 0.04831 * 4.05 = 0.23889

[0499] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0500] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.095 * 36534 * 51.7% * (1.0 + 0.15994) = 23990.4 (KN)

[0501] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 1.048 * 32204 * 45% * (1.0 + 0.22102) = 18544.1 (KN)

[0502] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 1.08 * 32326 * 40.8% * (1.0 + 0.32024) = 18805.7 (KN)

[0503] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 1.004 * 37729 * 35.2% * (1.0 + 0.23889) = 16519.0 (KN)

[0504] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0505]

[0506]

[0507] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0508] The rolling pressure deviation of each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 2.01 mm, and the actual thickness is 2.00 mm. The rolling is stable without overcurrent phenomenon, meeting the rolling requirements.

[0509] Example 21:

[0510] This example rolls carbon steel. Coil number: 929099501, steel grade: Q235B; billet thickness 230 mm, billet width 1060 mm, rough rolling target thickness 40 mm; strip finished product target thickness 1.40 mm, target width 1050 mm.

[0511] High-speed steel rolls are used for stands F0 - F3 of this piece of steel.

[0512] 1. Load distribution for high-speed steel rolls

[0513] The load distribution (%) of each stand of this specification is: 61.2, 55.0, 48.4, 45.5, 32.3, 28.8, 19.4. According to Table 1, the load adjustment amounts (%) of F0 - F3 are +4, +4, +4, +4 respectively. After adjustment, the load distributions (%) of F0 - F3 are: F0: 61.2 * (1 + 4%) = 63.6; F1: 55.0 * (1 + 4%) = 57.2; F2: 48.4 * (1 + 4%) = 50.3; F3: 45.5 * (1 + 4%) = 47.3. After adjustment, the load distributions (%) of F0 - F6 are 63.6, 57.2, 50.3, 47.3, 32.3, 28.8, 19.4.

[0514] 2. Rolling pressure control for high-speed steel rolls

[0515] The calculation data such as the load distribution LV, hardness MH, inlet temperature (TE), inlet thickness (HE), inlet width (WHEN), final reduction rate EPS, work roll diameter (WRR), rolling speed (31.5, 28.8, 21.3U), pressure correction coefficient nnfk, etc. of each stand of this piece of steel are as follows:

[0516] Item Unit F0 F1 F2 F3 F4 F5 F6 LV ％ 63.6 57.2 50.3 47.3 32.3 28.8 19.4 MH kN 33989 30806 31816 37801 43678 46669 58564 TE ℃ 1029.63 1000.92 975.68 953.68 934.32 915.15 896.58 HE mm 40.799 18.45 9.361 5.306 3.145 2.27 1.707 EPS ％ 54.8 49.3 43.3 40.7 27.8 24.8 16.7 WHEN mm 1085 1085 1085 1085 1085 1085 1085 WRR mm 377.5 330.3 314.6 311.45 320.6 308.2 330 VU m / s 0.69 1.36 2.39 4.05 5.76 7.71 9.39 nnfk 1.121 1.097 1.183 0.966 1.087 1.144 1.178

[0517] According to Table 2, the roll correction coefficients coff_rolltype of each stand are calculated as follows:

[0518] coff_rolltype(0) = -0.5488 + 0.001686TE - 1.1344EPS - 0.001220WRR + 0.06146VU = -0.5488 + 0.001686 * 1029.63 - 1.1344 * 54.8% - 0.001220 * 377.5 + 0.06146 * 0.69 = 0.1473624

[0519] coff_rolltype(1) = -1.3122 + 0.001180TE - 0.3495EPS - 0.000441WRR + 0.03720VU = -1.3122 + 0.001180 * 1000.92 + 0.3495 * 49.3% + 0.000441 * 330.3 + 0.03720 * 1.36 = 0.2374434

[0520] coff_rolltype(2) = -1.0748 + 0.001507TE + 0.2734EPS - 0.001253WRR + 0.07869VU = -1.0748 + 0.001507 * 975.68 + 0.2734 * 43.3% - 0.001253 * 314.6 + 0.07869 * 2.39 = 0.30781

[0521] coff_rolltype(3) = -0.7535 + 0.001231TE - 0.2271EPS - 0.000989WRR + 0.04831VU = -0.7535 + 0.001231 * 953.68 - 0.2271 * 40.7% - 0.000989 * 311.45 + 0.04831 * 4.05 = 0.21568

[0522] According to formula (3), the rolling pressures F0 to F3 are calculated as follows:

[0523] F(0) = nnfk(0) * MH(0) * EPS(0) * (1.0 + coff_rolltype(0)) = 1.121 * 33989 * 54.8% * (1.0 + 0.1473624) = 23956.6 (KN)

[0524] F(1) = nnfk(1) * MH(1) * EPS(1) * (1.0 + coff_rolltype(1)) = 1.097 * 30806 * 49.3% * (1.0 + 0.2374434) = 20616.5 (KN)

[0525] F(2) = nnfk(2) * MH(2) * EPS(2) * (1.0 + coff_rolltype(2)) = 1.183 * 31816 * 43.3% * (1.0 + 0.30781) = 21313.9 (KN)

[0526] F(3) = nnfk(3) * MH(3) * EPS(3) * (1.0 + coff_rolltype(3)) = 0.966 * 37801 * 40.7% * (1.0 + 0.21568) = 18067.3 (KN)

[0527] The calculated and actual values of the rolling pressure and roll gap for each stand are as follows:

[0528] Unit F0 F1 F2 F3 F4 F5 F6 Calculated F kN 23957 20616 21314 18067 13199 13241 11521 Actual F kN 24017 19982 21586 17935 12894 13006 10992 Calculated S mm 16.319 8.826 5.079 3.23 1.6 1.116 1.266 Actual S mm 16.001 8.932 5.001 3.309 1.723 1.231 1.305

[0529] Note: In the table, F represents the rolling pressure and S represents the roll gap.

[0530] The deviation of the rolling pressure for each stand is controlled within the range of ±10%. The target thickness of this piece of steel is 1.40 mm, and the actual thickness is 1.42 mm. The rolling is stable, without overcurrent phenomenon, meeting the rolling requirements.

[0531] The present invention has been disclosed above in preferred embodiments. However, those skilled in the art should understand that these embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. It should be noted that all equivalent changes and substitutions to these embodiments should be regarded as covered within the scope of the claims of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined in the claims.

Claims

1. A finish rolling method for high-speed steel rolls, characterized in that, it includes: Adjust the load distribution of the stand according to the rolling pressure: Only when the rolling pressure may cause an overcurrent phenomenon during the rolling process under the condition of high nickel-chromium rolls, but the maximum rolling pressure reached during the rolling process under the condition of high-speed steel rolls does not exceed the rolling pressure limit value, increase the load distribution of this stand; According to the roll type, add a roll correction coefficient during the calculation of the rolling pressure. Among them, the formula for calculating the rolling pressure is: F(i) = nnfk(i)*MH(i)*EPS(i)*(1.0 + coff_rolltype(i)) where, i represents the stand number of the finish rolling mill; F(i) represents the calculated rolling pressure of this stand of the finish rolling mill, kN; nnfk(i) represents the pressure correction coefficient of the i-th stand, dimensionless quantity; MH(i) represents the hardness value of the steel at the i-th stand, kN; EPS(i) represents the reduction ratio of the i-th stand, %; coff_rolltype(i) represents the roll correction coefficient, dimensionless quantity; Among them, the specific values of the roll correction coefficient are as follows: where, TE is the inlet temperature of this stand, °C; EPS is the reduction ratio, %; WRR is the work roll diameter, mm; VU is the rolling speed, m / s.

2. The finish rolling method for high-speed steel rolls according to claim 1, characterized in that, After using high-speed steel rolls for the first 4 stands in the finish rolling process, the load distribution adjustment rules for each steel type and specification are as follows: where, the width is the target width of the finished strip, and the thickness is the target thickness of the finished strip.

3. The finish rolling method for high-speed steel rolls according to claim 1, characterized in that, The formula for calculating the reduction ratio of the i-th stand is: EPS(i) = (THEN(i) - THEN(i + 1)) / THEN(i) In the formula, THEN(i) represents the inlet thickness of the i-th stand, mm; THEN(i + 1) represents the outlet thickness of the i-th stand, mm.

4. The finish rolling method for high-speed steel rolls according to claim 1, characterized in that, The calculation process of the pressure correction coefficient nnfk(i) for the i-th stand is as follows: The pressure correction coefficient nnfk(i a ) for each rolled steel piece is recorded together with the corresponding steel grade, thickness, width, and chemical composition to establish a database; where the calculation method of nnfk(i a ) is as follows: nnfk(i a ) = nnfk(i 0 ) + 0.68 * (F(i 0 ) - F(i 00 )) / F(i 00 ) Among them, nnfk(i a ) represents the pressure correction coefficient of each piece of rolled steel, a dimensionless quantity; nnfk(i 0 ) represents the pressure correction coefficient of the upper block steel, a dimensionless quantity; F(i 0 ) represents the actual pressure during the rolling of the upper block of steel, in KN; F(i 00 ) represents the calculated rolling pressure of the upper block of steel, KN; Among them, the confirmation of the pressure correction coefficient nnfk(i) is divided into two cases: long genetic value and short genetic value.

5. The finish rolling method for high-speed steel rolls according to claim 4, characterized in that, The determination conditions for the long genetic value are at least one of the following conditions: 1) When the steel type of this slab is different from that of the previous slab, take the long genetic value; 2) When the thickness of this slab is greater than or equal to 10% compared with the thickness of the previous slab, take the long genetic value; 3) When the width of this slab is greater than or equal to 10% compared with the width of the previous slab, take the long genetic value.

6. The finish rolling method for high-speed steel rolls according to claim 4, characterized in that, The method for determining the long genetic value is as follows: In the pressure correction coefficient nnfk(i a ) database, take the average value of the pressure correction coefficients nnfk(i a ) of the 30 steels closest to it as the pressure correction coefficient nnfk(i) of this piece of steel; when the number of similar steels in the database is less than 30 pieces of steel, take the average value of the pressure correction coefficients nnfk(i a ) of the actual number of steel pieces; when there is no such steel type in the database, the pressure correction coefficient nnfk(i) takes the default value of 1.

0.

7. The finish rolling method for high-speed steel rolls according to claim 4, characterized in that, The determination condition of the short genetic value is as follows: when the steel grades are the same and the changes in thickness and width are less than 10%, the short genetic value is taken; the short genetic value is the calculated value of the pressure correction coefficient nnfk(i a ) of the previous slab of steel.

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