Method for forecasting influence of phosphorus content of phosphorus-containing steel on rolling speed in cold rolling process

Abstract

The invention relates to a method for forecasting the influence of phosphorus content of phosphorus-containing steel on rolling speed in a cold rolling process, which comprises the following steps of: A) setting rolling parameters of the phosphorus-containing steel, B) solving the reduced carbon equivalent of the phosphorus-containing steel, C) solving the actual deformation resistance of the phosphorus-containing steel, D) calculating initial rolling force P by using R, E) calculating R 'by using the rolling force P, F) calculating P' by using R ', G) judging that R-R' is less than or equal to delta, and if R-R '< = delta, skipping to H), and if R-R' > delta, letting P = P 'and R = R', and skipping to E). H) calculating the forward slip value fs, I) calculating the rolling moment M, and J) calculating the rolling speed v of the phosphorus-containing steel. According to the method, the actual deformation resistance of the cold-rolled strip steel can be calculated by fully combining the equipment characteristics of the five-rack six-roller cold continuous rolling unit according to the field production condition of the cold-rolled strip steel, the rolling force of the phosphorus-containing steel under a certain rolling reduction is calculated, and finally the rolling speed is obtained by utilizing the calculated rolling force under the condition of giving a certain rolling power. Therefore, the influence of the phosphorus content on the rolling speed in the cold rolling process of the phosphorus-containing steel is forecasted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cold rolling mill rolling speed control in the process of rolling phosphorus-containing steel, and particularly relates to a method for predicting the influence of rolling speed in the process of cold rolling of phosphorus-containing steel. BACKGROUND

[0002] In recent years, with the continuous development of modern manufacturing technology, phosphorus has been added to automobile steel as a strengthening element to improve its strength. It is found through research that the phosphorus content of phosphorus-containing steel changes its strength, hardness and elongation, etc. The increase of strength and hardness will affect the rolling speed during rolling. In actual production, the prediction of rolling mill rolling speed can improve production efficiency, reduce energy consumption, labor cost, etc., which has important economic significance for enterprises. Therefore, in order to improve the quality and production stability of cold-rolled phosphorus-containing steel products, it is necessary to fully combine the actual production situation of the cold rolling site, combine the characteristics of the rolling mill, and explore a set of methods for predicting the influence of rolling speed in the process of cold rolling of phosphorus-containing steel.

[0003] Comparison of Prior Art

[0004] Invention patent: Production process of phosphorus-added high-strength interstitial-free steel (application number: CN201610548905.1), the present application discloses a production process of phosphorus-added high-strength interstitial-free steel, which comprises the steps of hot metal desulfurization, converter smelting, RH vacuum treatment and conventional slab continuous casting. The method uses a converter with a nominal capacity of less than 110t to produce phosphorus-added high-strength interstitial-free steel. By controlling the non-inverted furnace of the converter to directly tap the molten steel, reducing the temperature drop from the converter to the ladle, using a vacuum mechanical pump to quickly, accurately and stably control the carbon content, stabilizing the production rhythm, and using constant speed and other process measures to produce continuous casting billets that meet the requirements, hot-rolled high-quality hot-rolled coil sheets, and finally produce high-quality continuous annealing products through cold rolling. The method controls the process parameters of each process to produce continuous casting billets that meet the requirements, hot-rolled high-quality hot-rolled coil sheets, and finally produce high-quality continuous annealing products through cold rolling.

[0005] Invention patent: a method for improving the whole rolling process of phosphorus-containing high-strength IF steel by rare earth treatment (application number: CN202010419367.2), the present invention discloses a method for improving the whole rolling process of phosphorus-containing high-strength IF steel by rare earth treatment, including: at the end of the RH refining process, adding Mn iron, Ti iron, Nb iron and boron iron for alloying during the RH vacuum treatment process, adding rare earth cerium iron alloy after 3min of alloying, so that the Ce content of molten steel reaches 20ppm; the rolling process sample is polished, and the content and intensity of beneficial texture are compared and analyzed by XRD detection. The purpose of the present invention is to provide a method for improving the whole rolling process of phosphorus-containing high-strength IF steel by rare earth treatment, adding rare earth Ce in steel, effectively increasing the solid solution amount of P element in steel, improving the solid solution strengthening effect of P element in high-strength IF steel, obtaining a larger proportion of {111} beneficial texture, thereby improving the forming performance index r90 value, and making the phosphorus-containing high-strength IF steel have better stamping performance.

[0006] Paper: Gu Tie, Hu Shaoxin, Tao Jiawei. Research on mechanical properties of phosphorus-containing medium carbon steel [J]. Modern Metallurgy, 2018, 46(05): 1-4. The influence of different phosphorus content and grain size on the mechanical properties of medium carbon steel was studied, and the influence of yield strength, impact toughness and ductile-brittle transition temperature was studied. The results show that phosphorus solid solution in ferrite significantly improves the strength of the steel; phosphorus easily segregates at the ferrite grain boundary, increasing the ductile-brittle transition temperature, and the larger the grain size, the greater the segregation degree. Refining the grain can reduce the degree of phosphorus segregation at the grain boundary, thereby improving the strength and impact toughness of the steel, and reducing the ductile-brittle transition temperature. Therefore, refining the grain can effectively compensate for the loss of toughness of phosphorus-containing steel. SUMMARY

[0007] The present application fully combines the equipment characteristics of five-stand six-roll cold continuous rolling mill, and obtains a carbon equivalent calculation formula of phosphorus-containing steel through a large amount of field data regression, so as to calculate the equivalent carbon equivalent of phosphorus-containing steel by taking the phosphorus content of phosphorus-containing steel as an input variable, so as to calculate the actual deformation resistance, and the rolling force of the phosphorus-containing steel at a certain reduction amount is calculated, and finally the rolling speed is obtained under the condition of a certain rolling power.

[0008] The present application fully combines the equipment characteristics of five-stand six-roll cold continuous rolling mill, and obtains a carbon equivalent calculation formula of phosphorus-containing steel through a large amount of field data regression, so as to calculate the equivalent carbon equivalent of phosphorus-containing steel by taking the phosphorus content of phosphorus-containing steel as an input variable, so as to calculate the actual deformation resistance, and the rolling force of the phosphorus-containing steel at a certain reduction amount is calculated, and finally the rolling speed is obtained under the condition of a certain rolling power.

[0009] A) Set the phosphorus-containing steel rolling parameters, mainly including: phosphorus-containing steel carbon content c, phosphorus content, other element content (according to the actual carbon equivalent calculation formula); carbon equivalent proportion coefficient η; the i-th stand strip inlet thickness H; the i-th stand strip outlet thickness h; the i-th stand target deformation resistance σ i ; The i-th stand unit tension σ 前 ; The i-th stand unit tension σ 后 ; The incoming material width B; The i-th stand work roll diameter D; The i-th stand friction coefficient μ; The elastic modulus E; The Poisson's ratio v; The iteration parameter Δ; The rolling power W; The motor efficiency η.

[0010] Set the actual carbon equivalent calculation formula C ac of the specific phosphorus-containing steel grade, which is directly given by a large number of field actual data regression.

[0011]

[0012] In the formula: c—carbon content in phosphorus-containing steel (%);

[0013] ω (Mn) —manganese content in phosphorus-containing steel (%);

[0014] ω (P) —phosphorus content in phosphorus-containing steel (%);

[0015] ω (B) —boron content in phosphorus-containing steel (%);

[0016] ω (Sn) —tin content in phosphorus-containing steel (%);

[0017] ω (Ca) —calcium content in phosphorus-containing steel (%).

[0018] B) Solve the equivalent carbon equivalent of phosphorus-containing steel:

[0019] C i =C ac -c

[0020] In the formula: C i —equivalent carbon equivalent (%).

[0021] C) Solve the actual deformation resistance of phosphorus-containing steel:

[0022] K=σ i +ηC i

[0023] In the formula: K—actual deformation resistance;

[0024] η—carbon equivalent proportion coefficient.

[0025] D) Let Calculate the initial rolling force P using R:

[0026]

[0027] Where: P—initial rolling force;

[0028] R—radius of the working roller of the i-th stand;

[0029] Δh—absolute reduction per pass, Δh=Hh;

[0030] ξ—Equivalent tension influence coefficient, ξ=0.3σ 前 +0.7σ 后 ;

[0031] B—incoming material width;

[0032] ν—Poisson’s ratio;

[0033] Q F —The external friction influence coefficient is expressed as follows:

[0034]

[0035] r—pass reduction rate,

[0036] E) Calculate R' using rolling force P:

[0037]

[0038] Where: R'—flattening radius of the working roll of the i-th stand;

[0039] E—elastic modulus.

[0040] F) Calculate P' using R':

[0041]

[0042] Where: P'—iterative rolling force;

[0043] Q F '—External friction influence coefficient, expressed as follows:

[0044]

[0045] G) Determine |R-R'|≤Δ. If |R-R'|≤Δ, jump to H). If |R-R'|>Δ, set P=P', R=R' and jump to E).

[0046] H) Calculate the forward slip value f s .

[0047]

[0048] wherein: μ - friction coefficient.

[0049] I) Calculate rolling torque M.

[0050]

[0051] wherein: ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ;

[0052] Q G - external friction influence coefficient, expressed by the following formula:

[0053]

[0054] r - pass reduction rate,

[0055] J) Calculate rolling speed v of phosphorus-containing steel.

[0056]

[0057] wherein: W - rolling power;

[0058] η - motor efficiency;

[0059] The advantages of the present application relative to the prior art are as follows: (1) the present application can obtain an actual carbon equivalent calculation formula of phosphorus-containing steel through a large amount of field data regression according to the field production conditions of cold-rolled strip steel, fully combines the equipment characteristics of a five-stand six-roll cold continuous rolling mill, calculates the equivalent carbon equivalent of phosphorus-containing steel with phosphorus content as an input variable, thereby calculating the actual deformation resistance, calculating the rolling force of the phosphorus-containing steel at a certain reduction, and ultimately obtaining the rolling speed under the condition of a certain rolling power, that is, realizing the prediction of the influence of phosphorus content on rolling speed in the cold rolling process of phosphorus-containing steel; (2) the present application can more accurately predict the exit speed of a certain stand of a five-stand cold continuous rolling mill when rolling phosphorus-containing steel before production, so as to adjust the rolling parameter setting, thereby improving the product quality of the strip steel and ensuring the rolling stability in the cold rolling process of phosphorus-containing steel, and bringing greater economic benefits to the enterprise. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 The present application is a phosphorus content influence prediction method flow chart in the cold rolling process of phosphorus-containing steel. DETAILED DESCRIPTION

[0061] Taking the first stand of a certain five-stand six-roll cold continuous rolling mill rolling a certain phosphorus-containing steel as an example, combining the Figure 1The application discloses a method for predicting the influence of phosphorus content on rolling speed in a cold rolling process of phosphorus-containing steel.

[0062] Embodiment 1

[0063] Firstly, in step A), rolling parameters of the phosphorus-containing steel are set, mainly including: carbon content c, phosphorus content, other element content (calculated according to an actual carbon equivalent formula) of the phosphorus-containing steel; a carbon equivalent proportion coefficient η; a first-stand strip inlet thickness H; a first-stand strip outlet thickness h; a first-stand target deformation resistance σ i ; a first-stand front unit tension σ 前 ; a first-stand rear unit tension σ 后 ; a raw material width B; a first-stand work roll diameter D; a first-stand friction coefficient μ; an elastic modulus E; a Poisson's ratio v; an iteration parameter Δ; a rolling power W; and a motor efficiency η.

[0064] Table 1 Rolling parameters of the phosphorus-containing steel DQ1461H5

[0065]

[0066]

[0067] A specific actual carbon equivalent calculation formula C ac of the phosphorus-containing steel is set, and the formula is directly given according to a large amount of field actual data regression:

[0068]

[0069] In the formula, c represents carbon content (%) in the phosphorus-containing steel;

[0070] ω (Mn) represents manganese content (%) in the phosphorus-containing steel;

[0071] ω (P) represents phosphorus content (%) in the phosphorus-containing steel;

[0072] ω (B) represents boron content (%) in the phosphorus-containing steel;

[0073] ω (Sn) represents tin content (%) in the phosphorus-containing steel;

[0074] ω (Ca) represents calcium content (%) in the phosphorus-containing steel.

[0075] Subsequently, in step B), the equivalent carbon equivalent of the phosphorus-containing steel is solved:

[0076] C i =C ac -c

[0077] wherein: C i —carbon equivalent (%).

[0078] The carbon equivalent C was calculated to be: i = 0.0549%.

[0079] Subsequently, in step C), the actual deformation resistance of the phosphorus-containing steel was solved:

[0080] K = σ i + ηC i

[0081] wherein: K - actual deformation resistance;

[0082] η - carbon equivalent proportionality coefficient.

[0083] The actual deformation resistance K was calculated to be 700.41 MPa.

[0084] Subsequently, in step D), the initial rolling force P was calculated using R:

[0085] wherein: P - initial rolling force;

[0086] R - i-th stand working roll radius;

[0087] Δh - absolute pass reduction amount, Δh = H - h;

[0088] ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ;

[0089] B - incoming width;

[0090] ν - Poisson's ratio;

[0091] Q F - external friction influence coefficient, expressed by the following formula:

[0092]

[0093]

[0094] r - pass reduction rate,

[0095] The initial rolling force P was calculated to be 7637504.161 N.

[0096] Subsequently, in step E), the flattened radius R' of the i-th stand working roll was calculated using the rolling force P:

[0097]

[0098] wherein: R' - i-th stand working roll flattened radius;

[0099] ​E - modulus of elasticity.

[0100] R' = 231.867 mm is calculated.

[0101] P' is then calculated in step F) using R':

[0102]

[0103] P' - iterative rolling force;

[0104] Q F - coefficient of external friction, expressed by the formula:

[0105]

[0106] P' = 8326859.969 N is calculated.

[0107] In step G) it is then checked whether |R - R'| < Δ, |R - R'| = |202 - 231.867| = 29.867 > Δ = 0.05, P = P' and R = R' are set and the flow is jumped to E).

[0108] R' is then calculated in step E) using the rolling force P:

[0109]

[0110] R' - flattened radius of the work roll of the i-th stand;

[0111] E - modulus of elasticity.

[0112] R' = 234.563 mm is calculated.

[0113] P' is then calculated in step F) using R':

[0114]

[0115] P' - iterative rolling force;

[0116] Q F - coefficient of external friction, expressed by the formula:

[0117]

[0118] P' = 8387742.686 N is calculated.

[0119] In step G) it is then checked whether |R - R'| < Δ, |R - R'| = |231.867 - 234.563| = 2.696 > Δ = 0.05, P = P' and R = R' are set and the flow is jumped to E).

[0120] R' is then calculated in step E) from the rolling force P:

[0121]

[0122] where: R' - flattened radius of the work roll in the i-stand;

[0123] E - modulus of elasticity.

[0124] R' = 234.8 mm is calculated.

[0125] P' is then calculated in step F) from R':

[0126]

[0127] where: P' - iterative rolling force;

[0128] Q F - coefficient of external friction, expressed by the formula:

[0129]

[0130] P' = 8393109.855 N is calculated.

[0131] In step G) it is then checked whether |R - R'| < Δ, |R - R'| = |234.563 - 234.8| = 0.237 > Δ = 0.05, then P = P' and R = R' and go to E).

[0132] R' is then calculated in step E) from the rolling force P:

[0133]

[0134] where: R' - flattened radius of the work roll in the i-stand;

[0135] E - modulus of elasticity.

[0136] R' = 234.822 mm is calculated.

[0137] P' is then calculated in step F) from R':

[0138]

[0139] where: P' - iterative rolling force;

[0140] Q F - coefficient of external friction, expressed by the formula:

[0141]

[0142] P' = 8393582.925 N is calculated.

[0143] Then in step G), it is judged whether |R-R'|≤Δ, |R-R'| = |234.8-234.822| = 0.022 < Δ = 0.05, then jump to H).

[0144] Then in step H), the front slip value f is calculated s .

[0145]

[0146] wherein: μ — friction coefficient.

[0147] f = 0.002 is calculated. s

[0148] Then in step I), the rolling moment M is calculated.

[0149]

[0150] wherein: ξ — equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 .

[0151] Q G — external friction influence coefficient, expressed by the following formula:

[0152]

[0153] r — pass reduction rate,

[0154] M = 181898.02 N·m is calculated.

[0155] Finally in step J), the rolling speed v of the phosphorus-containing steel is calculated.

[0156]

[0157] wherein: W — rolling power;

[0158] η — motor efficiency;

[0159] v = 234.982 m / min is calculated.

[0160] Example 2:

[0161] First in step A), the rolling parameters of the phosphorus-containing steel are set, mainly including: carbon element content c, phosphorus element content, other element content (calculated according to the actual carbon equivalent formula) of the phosphorus-containing steel; carbon equivalent proportion coefficient η; strip thickness H at the inlet of the 1st stand; strip thickness h at the outlet of the 1st stand; target deformation resistance σ of the 1st stand​i ; unit tension σ in front of 1st stand 前 ; unit tension σ in back of 1st stand 后 ; incoming material width B; 1st stand work roll diameter D; 1st stand friction coefficient μ; elastic modulus E; Poisson's ratio v; iteration parameter Δ; rolling power W; motor efficiency η.

[0162] Table 1 Rolling parameters of phosphorus-containing steel DQ1461H5

[0163]

[0164] Set the actual carbon equivalent calculation formula C of specific phosphorus-containing steel grade ac The formula is directly given by a large number of field actual data regression:

[0165]

[0166] In the formula: c - carbon element content in phosphorus-containing steel (%);

[0167] ω (Mn) - manganese element content in phosphorus-containing steel (%);

[0168] ω (P) - phosphorus element content in phosphorus-containing steel (%);

[0169] ω (B) - boron element content in phosphorus-containing steel (%);

[0170] ω (Sn) - tin element content in phosphorus-containing steel (%);

[0171] ω (Ca) - calcium element content in phosphorus-containing steel (%).

[0172] Then in step B), the actual carbon equivalent of phosphorus-containing steel is solved:

[0173] C i = C ac -c

[0174] In the formula: C i - equivalent carbon equivalent (%).

[0175] C i = 0.06%.

[0176] Then in step C), the actual deformation resistance of phosphorus-containing steel is solved:

[0177] K = σ i + ηC i

[0178] In the formula: K - actual deformation resistance;

[0179] η - carbon equivalent ratio coefficient.

[0180] K = 700.45 MPa is calculated.

[0181] Subsequently, in step D), let Calculate the initial rolling force P with R:

[0182]

[0183] where: P - initial rolling force;

[0184] R - i-th stand working roll radius;

[0185] Δh - absolute pass reduction amount, Δh = H - h;

[0186] ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ;

[0187] B - incoming width;

[0188] ν - Poisson's ratio;

[0189] Q F - external friction influence coefficient, expressed by the following formula:

[0190]

[0191] r - pass reduction rate,

[0192] P = 8004816.907 N is calculated.

[0193] Subsequently, in step E), calculate R' with rolling force P:

[0194]

[0195] where: R' - i-th stand working roll flattening radius;

[0196] E - elastic modulus.

[0197] R' = 233.303 mm is calculated.

[0198] Subsequently, in step F), calculate P' with R':

[0199]

[0200] where: P' - iterative rolling force;

[0201] Q F ' - external friction influence coefficient, expressed by the following formula:

[0202]

[0203] P' = 8875531.482 N is calculated.

[0204] Then in step G), if |R - R'| < Δ, |R - R'| = |202 - 233.303| = 31.303 > Δ = 0.05, then P = P', R = R' and jump to E).

[0205] Then in step E), R' is calculated from the rolling force P:

[0206]

[0207] where: R' - flattened radius of the work roll in the i-stand;

[0208] E - modulus of elasticity.

[0209] R' = 236.708 mm is calculated.

[0210] Then in step F), P' is calculated from R':

[0211]

[0212] where: P' - iterative rolling force;

[0213] Q F - coefficient of external friction influence, expressed by the formula:

[0214]

[0215] P' = 8959743.843 N is calculated.

[0216] Then in step G), if |R - R'| < Δ, |R - R'| = |233.303 - 236.708| = 3.405 > Δ = 0.05, then P = P', R = R' and jump to E).

[0217] Then in step E), R' is calculated from the rolling force P:

[0218]

[0219] where: R' - flattened radius of the work roll in the i-stand;

[0220] E - modulus of elasticity.

[0221] R' = 237.038 mm is calculated.

[0222] Then in step F), P' is calculated from R':

[0223]

[0224] P' = P + Q (R - R')

[0225] Q F P' = P + Q (R - R')

[0226]

[0227] P' = 8967871.344 N

[0228] Then in step G) it is determined whether |R - R'| < Δ, |R - R'| = |236.708 - 237.038| = 0.33 > Δ = 0.05, then P = P', R = R' and jump to E).

[0229] Then in step E) R' is calculated using the rolling force P:

[0230]

[0231] R' = R - Q (P - P')

[0232] E = modulus of elasticity.

[0233] R' = 237.069 mm

[0234] Then in step F) P' is calculated using R':

[0235] P' = P + Q (R - R') P' = P + Q (R - R')

[0236] P' = P + Q (R - R')

[0237] Q F P' = P + Q (R - R')

[0238] P' = P + Q (R - R')

[0239] P' = 8968655.586 N

[0240] Then in step G) it is determined whether |R - R'| < Δ, |R - R'| = |237.038 - 237.069| = 0.031 < Δ = 0.05, then jump to H).

[0241] Then in step I) the forward slip value f is calculated s .

[0242]

[0243] μ = coefficient of friction.

[0244] The calculation gives f s = 0.017.

[0245] Then in step I), the rolling moment M is calculated.

[0246]

[0247] Wherein: ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ;

[0248] Q G - external friction influence coefficient, expressed by the following formula:

[0249]

[0250] r - pass reduction rate,

[0251] The calculation gives M = 183643.782 N·m.

[0252] Finally in step J), the rolling speed v of the phosphorus-containing steel is calculated.

[0253]

[0254] Wherein: W - rolling power;

[0255] η - motor efficiency;

[0256] The calculation gives v = 236.26 m / min.

[0257] It should be noted that the above examples are not intended to limit the scope of protection of the present application, and equivalent transformations or substitutions made on the basis of the above technical solutions all fall within the scope of protection of the claims of the present application.

Claims

1. A method for predicting the effect of rolling speed on the phosphorus content during cold rolling of a phosphorus-containing steel, characterized in that, The method comprises the following steps: A) setting the rolling parameters of the phosphorus-containing steel, B) solving the equivalent carbon content of the phosphorus-containing steel, C) solving the actual deformation resistance of the phosphorus-containing steel, D) order Calculate initial rolling force P with R, E) calculating R' with the rolling force P, F) calculating P' with R', G) judging R-R'≤Δ, if R-R'≤Δ, then jumping to H), if R-R' > Δ, then P=P', R=R' and jumping to E), H) calculating the front slide value f s , I) calculating the rolling torque M, J) calculating the rolling speed v of the phosphorus-containing steel.

2. The method according to claim 1, characterized in that, A) setting phosphorus-containing steel rolling parameters, mainly including: phosphorus-containing steel carbon content c, phosphorus content, other element content (calculated according to the actual carbon equivalent formula); carbon equivalent proportion coefficient η; the thickness H of the strip steel entering the i-th rack; the thickness h of the strip steel exiting the i-th rack; the target deformation resistance σ i of the i-th rack; the unit tension σ 前 before the i-th rack; the unit tension σ 后 after the i-th rack; the incoming width B; the diameter D of the work roll of the i-th rack; the friction coefficient μ; the elastic modulus E; the Poisson's ratio v; the iteration parameter Δ; the rolling power W; the motor efficiency η, Set the specific phosphorus steel steel carbon equivalent calculation formula C ac , the formula is directly given by a large number of field data regression wherein: c - the carbon content in the phosphorus-containing steel (%); ω (Mn) Manganese content in phosphorus-containing steel (%); ω (P) P content in phosphorus-containing steel (%); ω (B) boron content in phosphorus-containing steel (%); ω (Sn) — tin content in phosphorus-containing steel (%); ω (Ca) — Calcium content in phosphorus-containing steel (%).

3. The method according to claim 1, characterized in that, B) solving the equivalent carbon content of the phosphorus-containing steel: C i = C ac - c In the formula: C i — Carbon equivalent (%).

4. The method of claim 1, wherein the phosphorus content of the steel is predicted by the equation: ###0001### wherein: P = phosphorus content of the steel, in weight percent; T = temperature of the steel, in °C; and v = rolling speed, in m / min. C) solving the actual deformation resistance of the phosphorus-containing steel: K = σ i + ηC i wherein: K - the actual deformation resistance; η - the carbon equivalent proportionality coefficient.

5. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: D) order Calculate initial rolling force P with R: wherein: P - the initial rolling force; R - the working roll radius of the i-th stand; Δh - the absolute pass reduction amount, Δh=H-h; ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ; B - the incoming width; ν - the Poisson's ratio; Q F The external friction influence coefficient is expressed by the following equation: r - pass reduction rate, 6. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: E) calculating R' with the rolling force P: wherein: R' - the flattening radius of the working roll of the i-th stand; E - the elastic modulus.

7. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: F) calculating P' with R': wherein: P' - the iterative rolling force; Q F '—External friction influence coefficient, expressed as follows:

8. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: G) judging R-R'≤Δ, if R-R'≤Δ, then jumping to H), if R-R' > Δ, then P=P', R=R' and jumping to E).

9. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: H) calculating the front slide value f s , wherein: μ - the friction coefficient.

10. The method for predicting the effect of phosphorus content on rolling speed during cold rolling of phosphorus-containing steel according to claim 1, characterized in that: I) calculating the rolling torque M, where: ξ - equivalent tension influence coefficient, ξ = 0.3σ 前 + 0.7σ 后 ; Q G - the external friction influence coefficient, expressed by the following formula: r - pass reduction rate, J) calculating the rolling speed v of the phosphorus-containing steel, wherein: W - the rolling power; η - the motor efficiency.

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