阅读说明：本技术 一种热镀铝锌机组基于带钢c翘治理的张力优化设定方法 (Tension optimal setting method of hot-dip aluminum-zinc plating unit based on strip steel C warping treatment ) 是由 孙永旭 何锐 于 2020-03-24 设计创作，主要内容包括：本发明涉及一种热镀铝锌机组基于带钢C翘治理的张力优化设定方法,所述方法包括以下步骤：A)收集带钢相关参数；B)收集冷却段相关工艺参数；C)定义优化过程参数；D)计算带钢在退火炉内带钢张力；E)计算退火过程带钢折减系数；F)计算各工艺段下带钢宽度值；G)计算优化目标函数；H)判断W(F-i)≤W-y是否成立？若成立,则令F-i＝F-y,W(F-i)＝W-y转入步骤I)；否则直接转入步骤I)；I)判断F-y＜F-(max)是否成立？若成立,则令k＝k+1,并转入D)；若不成立,则转入K)；J)输出退火过程最优总张力F-y,完成镀铝锌机组连退炉内张力制度的优化设定。本发明通过对连退炉内张力制度优化设定,实现最佳的张力控制。(The invention relates to a tension optimal setting method of a hot-dip aluminum-zinc plating unit based on strip steel C warping treatment, which comprises the following steps: A) collecting relevant parameters of the strip steel; B) collecting relevant process parameters of a cooling section; C) defining optimization process parameters; D) calculating the strip steel tension of the strip steel in the annealing furnace; E) calculating the reduction coefficient of the strip steel in the annealing process; F) calculating the width value of the strip steel under each process section; G) calculating an optimization objective function; H) judgment of W (F) i )≤W y Whether or not to becomeImmediately If true, let F i ＝F y ,W(F i )＝W y Turning to step I); otherwise, directly turning to the step I); I) judgment of F y ＜F max Is there any If yes, let k be k +1, and go to D); if not, switching to K); J) output annealing process optimal total tension F y And finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit. The invention realizes the optimal tension control by optimally setting the tension system in the continuous annealing furnace.)

1. A tension optimal setting method of a hot dip aluminum zinc machine set based on strip steel C warping treatment is characterized by comprising the following steps:

A) collecting relevant parameters of the strip steel;

B) collecting relevant process parameters of a cooling section;

C) defining optimization process parameters;

D) calculating the strip steel tension of the strip steel in the annealing furnace;

E) calculating the reduction coefficient of the strip steel in the annealing process;

F) calculating the width value of the strip steel under each process section;

G) calculating an optimization objective function;

H) judgment of W (F)_i)≤W_yIs there any? If true, let F_i＝F_y,W(F_i)＝W_yTurning to step I); otherwise, directly turning to the step I);

I) judgment of F_y＜F_maxIs there any? If yes, let k be k +1, and go to D); if not, switching to K);

J) output annealing process optimal total tension F_yAnd finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit.

2. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

A) collecting strip steel specification parameters, mechanical property parameters and the like, including strip steel width B at normal temperature₀Thickness H of strip steel, elastic modulus E of strip steel material at normal temperature, and yield strength sigma_s。

3. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

B) collecting relevant technological parameters of the aluminum-zinc plating unit, including the temperature T of the upper surface and the lower surface of the strip steel at the outlet of the preheating section of the annealing furnace_D1、T_D2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the heating section of the annealing furnace of the aluminum-zinc plating unit_R1、T_R2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the cooling section of the annealing furnace of the aluminum-zinc plating unit_C1、T_C2Maximum total tension F allowed to be set for the strip in the annealing furnace_maxMinimum total tension F_min。

4. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

C) defining an optimization process parameter k, taking an initial value k as 1, and setting an initial value W of an objective function_y10000, the optimization step Δ F is set.

5. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

D) calculating the strip steel tension of the strip steel in the annealing furnace:

F_i＝F_min+(k+1)ΔF。

6. the tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

E) calculating the band steel reduction coefficient in the annealing process, wherein the band steel reduction coefficient comprises the average reduction coefficient of the elastic modulus of the upper surface and the lower surface of the band steel and the average reduction coefficient of the yield strength of the upper surface and the lower surface of the band steel:

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel at the preheating section;

the elastic modulus reduction coefficient of the lower surface of the strip steel at the preheating section;

-the average reduction coefficient of the elastic modulus of the upper surface of the strip steel of the heating section;

-the average reduction coefficient of the elastic modulus of the lower surface of the strip steel of the heating section;

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel of the cooling section;

-the reduction coefficient of the elastic modulus of the lower surface of the strip steel of the cooling section;

-yield strength reduction factor of the upper surface of the strip steel of the preheating section;

-the yield strength reduction factor of the lower surface of the strip steel of the preheating section;

-the yield strength reduction factor of the upper surface of the strip steel of the heating section;

-the yield strength reduction factor of the lower surface of the strip steel of the heating section;

-the yield strength reduction factor of the upper surface of the strip steel of the cooling section;

-the yield strength reduction factor of the lower surface of the strip steel of the cooling section.

7. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

F) calculating the width value of the strip steel under each process section:

B_D-a preheating section width value;

α_tDthe linear expansion coefficient of the strip material in the preheating zone, α_tD＝11.8×10^-6/℃；

B_R-heating the section strip width value;

α_tR-linear expansion coefficient of strip material of heating section, alpha_tR＝9.83×10^-6/℃；

B_C-cooling section strip width value;

α_tCthe coefficient of linear expansion, alpha, of the strip material of the cooling section_tC＝11.8×10^-6/℃。

8. The tension optimization setting method of the hot dip aluminum zinc machine set based on the strip steel C warping treatment according to claim 1,

G) calculating an optimization objective function W (y):

Δb_D1the upper surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

Δb_D2the lower surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

s_Δb1the surface narrowing amount distribution unevenness of the preheating section strip steel when C warping occurs;

Δb_R1when the C warping occurs to the strip steel in the heating section, the upper surface is not uniformly and transversely narrowed;

Δb_R2the lower surface of the heating section strip steel is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb2the surface narrowing amount distribution unevenness of the heating section strip steel when C warping occurs;

Δb_C1the upper surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

Δb_C2the lower surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb3the surface narrowing amount distribution unevenness of the strip steel in the cooling section when C warping occurs;

alpha-technological coefficient

Beta-correction factor.

Technical Field

The invention relates to an optimization method, in particular to a tension optimization setting method of a hot-dip aluminum-zinc plating unit based on strip steel C warping treatment, and belongs to the technical field of temperature control in a continuous annealing furnace in a steel rolling process.

Background

The cold-rolled strip steel continuous annealing process is used for eliminating cold work hardening and internal stress of the strip steel, reducing the hardness of the steel and enabling the strip steel to have good mechanical properties. In the continuous annealing production process, tensile stress as a main production process parameter not only directly influences the through plate stability of the strip, but also is closely related to the narrowing amount of the strip and the shape of an outer plate in a furnace. Meanwhile, the influence of the tensile stress on the stability and the narrowing amount of the strip through plate and the shape of the plate inside and outside the furnace is not only the characteristic process parameters of the specification, the material quality and the like of the strip.

The stable operation of the strip steel in the furnace mainly has two parts, namely, tension rollers at two ends of a continuous annealing furnace; and the other is a furnace bottom roller or a driving roller which plays a role in supporting the strip steel in each process section in the furnace. The tension rollers at the two ends of the continuous annealing furnace provide constant tension for the strip steel, so that the strip steel is always kept in a tight and straight state, and the strip shape is favorably kept. When the strip steel runs in the furnace, due to the influence difference of factors such as the temperature, the temperature rise amplitude and the like of each process section, the deformation amount of each part is different, the plastic deformation amount is different, and the transverse narrowing phenomenon is caused. If the narrowing phenomenon is not uniformly distributed in the thickness direction, the C warp is likely to occur,

therefore, in order to improve the plate shape quality of cold-rolled products, a set of control method for the tension system in the annealing furnace of the aluminum-zinc plating machine set, which can be fully used, must be developed by fully combining the actual production condition of a cold-rolling field and combining the characteristics of the tension system of each process section of the horizontal continuous annealing furnace on the premise of fully knowing the equipment conditions of the continuous annealing machine set.

Disclosure of Invention

The invention provides a tension optimal setting method of a hot dip aluminum zinc machine set based on strip steel C warping treatment aiming at the problems in the prior art, and the scheme realizes optimal tension control by optimally setting a tension system in a continuous annealing furnace.

In order to achieve the purpose, the technical scheme of the invention is as follows: a tension optimal setting method of a hot dip aluminum zinc machine set based on strip steel C warping treatment comprises the following steps:

A) collecting strip steel specification parameters, mechanical property parameters and the like, including strip steel width B at normal temperature₀Thickness H of strip steel, elastic modulus E of strip steel material at normal temperature, and yield strength sigma_s；

B) Collecting relevant technological parameters of the aluminum-zinc plating unit, including the temperature T of the upper surface and the lower surface of the strip steel at the outlet of the preheating section of the annealing furnace_D1、T_D2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the heating section of the annealing furnace of the aluminum-zinc plating unit_R1、T_R2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the cooling section of the annealing furnace of the aluminum-zinc plating unit_C1、T_C2Maximum total tension F allowed to be set for the strip in the annealing furnace_maxMinimum total tension F_min；

C) Defining an optimization process parameter k, taking an initial value k as 1, and setting an initial value W of an objective function_y10000, the optimization step Δ F is set.

D) Calculating the strip steel tension of the strip steel in the annealing furnace:

F_i＝F_min+(k+1)ΔF

E) calculating the band steel reduction coefficient in the annealing process, wherein the band steel reduction coefficient comprises the average reduction coefficient of the elastic modulus of the upper surface and the lower surface of the band steel and the average reduction coefficient of the yield strength of the upper surface and the lower surface of the band steel:

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel at the preheating section;

the elastic modulus reduction coefficient of the lower surface of the strip steel at the preheating section;

the elastic modulus of the upper surface of the strip steel of the heating section is flatThe average reduction factor;

-the average reduction coefficient of the elastic modulus of the lower surface of the strip steel of the heating section;

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel of the cooling section;

-the reduction coefficient of the elastic modulus of the lower surface of the strip steel of the cooling section;

-yield strength reduction factor of the upper surface of the strip steel of the preheating section;

-the yield strength reduction factor of the lower surface of the strip steel of the preheating section;

-the yield strength reduction factor of the upper surface of the strip steel of the heating section;

-the yield strength reduction factor of the lower surface of the strip steel of the heating section;

-the yield strength reduction factor of the upper surface of the strip steel of the cooling section;

-the yield strength reduction factor of the lower surface of the strip steel of the cooling section;

F) calculating the width value of the strip steel under each process section:

B_D-a preheating section width value;

α_tDthe linear expansion coefficient of the strip material in the preheating zone, α_tD＝11.8×10^-6/℃；

B_R-heating the section strip width value;

α_tR-linear expansion coefficient of strip material of heating section, alpha_tR＝9.83×10^-6/℃；

B_C-cooling section strip width value;

α_tCthe coefficient of linear expansion, alpha, of the strip material of the cooling section_tC＝11.8×10^-6/℃；

G) Calculating an optimization objective function W (y):

Δb_D1the upper surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

Δb_D2the lower surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

s_Δb1the surface narrowing amount distribution unevenness of the preheating section strip steel when C warping occurs;

Δb_R1when the C warping occurs to the strip steel in the heating section, the upper surface is not uniformly and transversely narrowed;

Δb_R2the lower surface of the heating section strip steel is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb2the surface narrowing amount distribution unevenness of the heating section strip steel when C warping occurs;

Δb_C1the upper surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

Δb_C2the lower surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb3the surface narrowing amount distribution unevenness of the strip steel in the cooling section when C warping occurs;

alpha-technological coefficient

Beta-correction factor

H) Judgment of W (F)_i)≤W_yIs there any? If true, let F_i＝F_y,W(F_i)＝W_yTurning to step I); otherwise, directly turning to the step I);

I) judgment of F_y＜F_maxIs there any? If yes, let k be k +1, and go to D); if not, switching to K);

J) output annealing process optimal total tension F_yAnd finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit.

Compared with the prior art, the invention has the following advantages:

1) the invention can fully combine the characteristics of the continuous annealing furnace of the aluminum-zinc plating group according to the field production condition of the cold-rolled strip steel, effectively solves the control problem of the warping defect of the strip steel of the unit by optimally setting the tension system in the continuous annealing furnace, and provides a new method for controlling the plate shape defect of the field cold rolling unit;

2) the annealing total tension is optimized and set by the method, the C warping defect of the aluminum-zinc plating unit is effectively improved, the C warping amount on the strip steel after the strip steel with the thickness of 1.5-2.5 mm is annealed is controlled within 18mm, the deviation amount of the coating on the upper surface of the strip steel is reduced to be within 3.5 g/square meter, the continuous sink roll printing defect at the edge of the aluminum-zinc plating strip steel is effectively improved, and the defect generation amount is reduced by more than 77%.

Drawings

FIG. 1 is a flow chart of a temperature optimization setting method of a hot-dip aluminum-zinc plating unit based on strip steel C warping prevention and control.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: referring to fig. 1, a tension optimization setting method of a hot dip aluminum zinc plating unit based on strip steel C warping treatment comprises the following steps:

A) collecting strip steel specification parameters, mechanical property parameters and the like, including strip steel width B at normal temperature₀Thickness H of strip steel, elastic modulus E of strip steel material at normal temperature, and yield strength sigma_s；

B) Collecting relevant technological parameters of the aluminum-zinc plating unit, including the temperature T of the upper surface and the lower surface of the strip steel at the outlet of the preheating section of the annealing furnace_D1、T_D2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the heating section of the annealing furnace of the aluminum-zinc plating unit_R1、T_R2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the cooling section of the annealing furnace of the aluminum-zinc plating unit_C1、T_C2Maximum total tension F allowed to be set for the strip in the annealing furnace_maxMinimum total tension F_min；

C) Defining an optimization process parameter k, taking an initial value k as 1, and setting an initial value W of an objective function_y10000, the optimization step Δ F is set.

D) Calculating the strip steel tension of the strip steel in the annealing furnace:

F_i＝F_min+(k+1)ΔF

E) calculating the band steel reduction coefficient in the annealing process, wherein the band steel reduction coefficient comprises the average reduction coefficient of the elastic modulus of the upper surface and the lower surface of the band steel and the average reduction coefficient of the yield strength of the upper surface and the lower surface of the band steel:

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel at the preheating section;

under strip in the preheating sectionSurface modulus of elasticity reduction coefficient;

-the average reduction coefficient of the elastic modulus of the upper surface of the strip steel of the heating section;

-the average reduction coefficient of the elastic modulus of the lower surface of the strip steel of the heating section;

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel of the cooling section;

-the reduction coefficient of the elastic modulus of the lower surface of the strip steel of the cooling section;

-yield strength reduction factor of the upper surface of the strip steel of the preheating section;

-the yield strength reduction factor of the lower surface of the strip steel of the preheating section;

-the yield strength reduction factor of the upper surface of the strip steel of the heating section;

-the yield strength reduction factor of the lower surface of the strip steel of the heating section;

-the yield strength reduction factor of the upper surface of the strip steel of the cooling section;

-the yield strength reduction factor of the lower surface of the strip steel of the cooling section;

F) calculating the width value of the strip steel under each process section:

B_D-a preheating section width value;

α_tDthe linear expansion coefficient of the strip material in the preheating zone, α_tD＝11.8×10^-6/℃；

B_R-heating the section strip width value;

α_tR-linear expansion coefficient of strip material of heating section, alpha_tR＝9.83×10^-6/℃；

B_C-cooling section strip width value;

α_tCthe coefficient of linear expansion, alpha, of the strip material of the cooling section_tC＝11.8×10^-6/℃；

G) Calculating an optimization objective function W (y):

Δb_D1the upper surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

Δb_D2the lower surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

s_Δb1the surface narrowing amount distribution unevenness of the preheating section strip steel when C warping occurs;

Δb_R1when the C warping occurs to the strip steel in the heating section, the upper surface is not uniformly and transversely narrowed;

Δb_R2the lower surface of the heating section strip steel is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb2the surface narrowing amount distribution unevenness of the heating section strip steel when C warping occurs;

Δb_C1the upper surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

Δb_C2the lower surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb3the surface narrowing amount distribution unevenness of the strip steel in the cooling section when C warping occurs;

alpha-technological coefficient

Beta-correction factor

H) Judgment of W (F)_i)≤W_yIs there any? If true, let F_i＝F_y,W(F_i)＝W_yTurning to step I); otherwise, directly turning to the step I);

I) judgment of F_y＜F_maxIs there any? If yes, let k be k +1, and go to D); if not, switching to K);

J) output annealing process optimal total tension F_yAnd finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit.

Application example 1: a tension optimal setting method of a hot dip aluminum zinc machine set based on strip steel C warping treatment comprises the following steps:

taking a tension optimization setting system of certain hot-dip aluminum zinc based on strip steel C warp prevention and control as an example, the tension optimization setting method suitable for hot-dip aluminum zinc based on strip steel C warp prevention and control, disclosed by the invention, is explained in detail with reference to fig. 1.

Firstly, in the step A), collecting the specification parameters, the mechanical property parameters and the like of the strip steel, including the width B of the strip steel at normal temperature₀Thickness H of strip steel, elastic modulus E of strip steel material at normal temperature, and yield strength sigma_s；

TABLE 1 strip Steel Specification parameters

Strip width/mm	Thickness/mm of strip steel	Modulus of elasticity of strip steel material at normal temperature	Yield strength of strip steel material at normal temperature
				1250	2	212GPa	235MPa

Then in the step B), the temperature T of the upper surface and the lower surface of the strip steel at the outlet of the preheating section of the annealing furnace of the aluminum-zinc plating unit is collected_D1、T_D2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the heating section of the annealing furnace of the aluminum-zinc plating unit_R1、T_R2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the cooling section of the annealing furnace of the aluminum-zinc plating unit_C1、T_C2Maximum total tension F allowed to be set for the strip in the annealing furnace_maxMinimum total tension F_max。

TABLE 2 Key strip steel rolling process parameters for strip shape and strip crown

Temperature T of upper surface of strip steel at outlet of preheating sectionD1	200℃	Temperature T of upper surface of outlet strip steel of cooling sectionD1	570℃
				Temperature T of lower surface of strip steel at outlet of preheating sectionD2	200℃	Lower surface temperature T of strip steel at outlet of cooling sectionD2	572℃
Temperature T of upper surface of strip steel at outlet of heating sectionR1	700℃	Maximum total tension F set in annealing furnacemax	25KN
				Lower surface temperature T of strip steel at outlet of heating sectionR2	710℃	Minimum total tension F set in annealing furnacemax	10KN

Then in step C), defining an optimization process parameter k, taking the initial value k as 1, and setting an initial value W of the objective function_y10000, the optimization step Δ F is set.

Subsequently, in step D), the strip tension in the annealing furnace is calculated:

F_i＝F_min+(k+1)ΔF

and then in the step E), calculating the reduction coefficients of the strip steel in the annealing process, wherein the reduction coefficients comprise the average reduction coefficient of the elastic modulus of the upper surface and the lower surface of the strip steel and the average reduction coefficient of the yield strength of the upper surface and the lower surface of the strip steel:

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel at the preheating section;

the elastic modulus reduction coefficient of the lower surface of the strip steel at the preheating section;

-the average reduction coefficient of the elastic modulus of the upper surface of the strip steel of the heating section;

-the average reduction coefficient of the elastic modulus of the lower surface of the strip steel of the heating section;

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel of the cooling section;

-the reduction coefficient of the elastic modulus of the lower surface of the strip steel of the cooling section;

-yield strength reduction factor of the upper surface of the strip steel of the preheating section;

-the yield strength reduction factor of the lower surface of the strip steel of the preheating section;

-the yield strength reduction factor of the upper surface of the strip steel of the heating section;

-the yield strength reduction factor of the lower surface of the strip steel of the heating section;

-the yield strength reduction factor of the upper surface of the strip steel of the cooling section;

-the yield strength reduction factor of the lower surface of the strip steel of the cooling section;

then in step F), calculating the width value of the strip steel under each process section:

B_D-a preheating section width value;

α_tDthe linear expansion coefficient of the strip material in the preheating zone, α_tD＝11.8×10^-6/℃；

B_R-heating the section strip width value;

α_tR-linear expansion coefficient of strip material of heating section, alpha_tR＝9.83×10^-6/℃；

B_C-cooling section strip width value;

α_tCthe coefficient of linear expansion, alpha, of the strip material of the cooling section_tC＝11.8×10^-6/℃；

Subsequently in step G), an optimization objective function w (y) is calculated:

Δb_D1the upper surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

Δb_D2the lower surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

s_Δb1the surface narrowing amount distribution unevenness of the preheating section strip steel when C warping occurs;

Δb_R1when the C warping occurs to the strip steel in the heating section, the upper surface is not uniformly and transversely narrowed;

Δb_R2the lower surface of the heating section strip steel is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb2the surface narrowing amount distribution unevenness of the heating section strip steel when C warping occurs;

Δb_C1the upper surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

Δb_C2the lower surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb3the surface narrowing amount distribution unevenness of the strip steel in the cooling section when C warping occurs;

α -Process coefficient;

beta-correction factor;

subsequently in step H), W (F) is judged_i)≤W_yIs there any? If true, let F_i＝F_y,W(F_i)＝W_yTurning to step I); otherwise, directly turning to the step I);

subsequently in step I), F is judged_y＜F_maxIs there any? If yes, let k be k +1, and go to D); if not, switching to K);

in the last step J), the optimal total tension F of the annealing process is output_yAnd finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit.

TABLE 3 comparison of shape before and after optimization of hot-dip Al-Zn tension

	Optimum total tension of annealing process	Amount of warpage/mm
			Before optimization	15KN	30
After optimization	12KN	20

Application example 2: a tension optimal setting method of a hot dip aluminum zinc machine set based on strip steel C warping treatment comprises the following steps:

firstly, in the step A), collecting the specification parameters, the mechanical property parameters and the like of the strip steel, including the width B of the strip steel at normal temperature₀Thickness H of strip steel, elastic modulus E of strip steel material at normal temperature, and yield strength sigma_s；

TABLE 4 strip Steel Specification parameters

Strip width/mm	Thickness/mm of strip steel	Modulus of elasticity of strip steel material at normal temperature	Strip steel material at normal temperatureLower yield strength
				1000	0.5	212GPa	235MPa

Then in the step B), the temperature T of the upper surface and the lower surface of the strip steel at the outlet of the preheating section of the annealing furnace of the aluminum-zinc plating unit is collected_D1、T_D2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the heating section of the annealing furnace of the aluminum-zinc plating unit_R1、T_R2The temperature T of the upper surface and the lower surface of strip steel at the outlet of the cooling section of the annealing furnace of the aluminum-zinc plating unit_C1、T_C2Maximum total tension F allowed to be set for the strip in the annealing furnace_maxMinimum total tension F_max。

TABLE 5 Key strip Steel Rolling Process parameters for strip shape and strip crown

Temperature T of upper surface of strip steel at outlet of preheating sectionD1	200℃	Temperature T of upper surface of outlet strip steel of cooling sectionD1	615℃
				Temperature T of lower surface of strip steel at outlet of preheating sectionD2	200℃	Lower surface temperature T of strip steel at outlet of cooling sectionD2	617℃
Temperature T of upper surface of strip steel at outlet of heating sectionR1	720℃	Maximum total tension F set in annealing furnacemax	27KN
				Lower surface temperature T of strip steel at outlet of heating sectionR2	729℃	Minimum total tension F set in annealing furnacemax	13KN

Then in step C), defining an optimization process parameter k, taking the initial value k as 1, and setting an initial value W of the objective function_y10000, the optimization step Δ F is set.

Subsequently, in step D), the strip tension in the annealing furnace is calculated:

F_i＝F_min+(k+1)ΔF

and then in the step E), calculating the reduction coefficients of the strip steel in the annealing process, wherein the reduction coefficients comprise the average reduction coefficient of the elastic modulus of the upper surface and the lower surface of the strip steel and the average reduction coefficient of the yield strength of the upper surface and the lower surface of the strip steel:

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel at the preheating section;

the elastic modulus reduction coefficient of the lower surface of the strip steel at the preheating section;

-the average reduction coefficient of the elastic modulus of the upper surface of the strip steel of the heating section;

-the average reduction coefficient of the elastic modulus of the lower surface of the strip steel of the heating section;

-the reduction coefficient of the elastic modulus of the upper surface of the strip steel of the cooling section;

-the reduction coefficient of the elastic modulus of the lower surface of the strip steel of the cooling section;

-yield strength reduction factor of the upper surface of the strip steel of the preheating section;

-the yield strength reduction factor of the lower surface of the strip steel of the preheating section;

-the yield strength reduction factor of the upper surface of the strip steel of the heating section;

-the yield strength reduction factor of the lower surface of the strip steel of the heating section;

-cooling downThe yield strength reduction coefficient of the upper surface of the section strip steel;

-the yield strength reduction factor of the lower surface of the strip steel of the cooling section;

then in step F), calculating the width value of the strip steel under each process section:

B_D-a preheating section width value;

α_tDthe linear expansion coefficient of the strip material in the preheating zone, α_tD＝11.8×10^-6/℃；

B_R-heating the section strip width value;

α_tR-linear expansion coefficient of strip material of heating section, alpha_tR＝9.83×10^-6/℃；

B_C-cooling section strip width value;

α_tCthe coefficient of linear expansion, alpha, of the strip material of the cooling section_tC＝11.8×10^-6/℃；

Subsequently in step G), an optimization objective function w (y) is calculated:

Δb_D1the upper surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

Δb_D2the lower surface of the preheating section strip steel is not uniformly and transversely narrowed when C warping occurs;

s_Δb1the surface narrowing amount distribution unevenness of the preheating section strip steel when C warping occurs;

Δb_R1when the C warping occurs to the strip steel in the heating section, the upper surface is not uniformly and transversely narrowed;

Δb_R2the lower surface of the heating section strip steel is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb2the surface narrowing amount distribution unevenness of the heating section strip steel when C warping occurs;

Δb_C1the upper surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

Δb_C2the lower surface of the strip steel in the cooling section is not uniformly and transversely narrowed when the strip steel is warped;

s_Δb3the surface narrowing amount distribution unevenness of the strip steel in the cooling section when C warping occurs;

α -Process coefficient;

beta-correction factor;

subsequently in step H), W (F) is judged_i)≤W_yIs there any? If true, let F_i＝F_y,W(F_i)＝W_yTurning to step I); otherwise, directly turning to the step I);

subsequently in step I), F is judged_y＜F_maxIs there any? If yes, let k be k +1, and go to D); if not, switching to K);

in the last step J), the optimal total tension F of the annealing process is output_yAnd finishing the optimized setting of the tension system in the continuous annealing furnace of the aluminum-zinc plating unit.

TABLE 6 comparison of shape before and after optimization of hot-dip Al-Zn tension

	Optimum total tension of annealing process	Amount of warpage/mm
			Before optimization	14kN	27
After optimization	16kN	16

。

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.