A method for distributing reduction between primary cold rolling and quasi-secondary cold rolling

Abstract

This invention relates to a method for allocating reduction between primary cold rolling and quasi-secondary cold rolling, comprising the following steps: acquiring equipment parameters of the cold rolling mill, acquiring rolling process parameters, defining constraint parameters for relevant sheet shapes, establishing models of various influencing factors of tinplate during cold rolling, finely optimizing the reduction allocation coefficient, and outputting the optimal reduction allocation value between primary and quasi-secondary cold rolling. The reduction allocation method between primary and quasi-secondary cold rolling provided by this invention ensures the achievement of key quality indicators and stable rolling performance of the cold rolling mill in the allocation of reduction between primary and quasi-secondary cold rolling.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of cold rolling and the distribution method of reduction between quasi secondary cold rolling, belong to metal smelting technical field. BACKGROUND

[0002] Quasi secondary cold rolling is the secondary cold rolling deformation of annealing strip with small reduction, as the last process of cold rolled strip production, it plays an important role in ensuring the surface quality, shape, size and mechanical properties of cold rolled strip.

[0003] After tinned plate is subjected to primary cold rolling and annealing, it enters double rack secondary cold rolling process, in primary cold rolling and secondary cold rolling process, the reduction distribution of two processes becomes the key indicator of actual production.In the prior art, the reduction distribution between primary cold rolling and quasi secondary cold rolling is generally determined by experience, and a table is given according to manual experience, but it cannot be refined, and can only be divided according to steel grade.The consequence is that the production capacity of primary cold rolling and quasi secondary cold rolling unit cannot be fully utilized, and the quality of products cannot be guaranteed. SUMMARY

[0004] The present application aims to overcome the shortcomings of the above-mentioned technology, and to provide a reduction distribution method between primary cold rolling and quasi secondary cold rolling, based on the constraint relationship between the reduction capacity, rolling stability and reduction distribution of primary cold rolling unit and quasi secondary cold rolling unit, and based on the reduction distribution domain that meets the strength index of strip, the method aims to maximize efficiency while meeting the reduction capacity and rolling stability of the unit.

[0005] To solve the above technical problems, the technical scheme provided by the present application is as follows: a reduction distribution method between primary cold rolling and quasi secondary cold rolling, comprising the following steps:

[0006] Step (1): obtaining the equipment parameters of cold rolling unit:

[0007] Roll radius R of each rack , motor efficiency , work roll linear speed , work roll surface roughness ;

[0008] Step (2): obtaining rolling process parameters:

[0009] Average deformation resistance of each rack of cold rolling unit , width B of strip, strip inlet thickness , strip outlet thickness , reduction , inlet tension , outlet tension , strip entry speed , and strip deformation resistance , back tension , strip density , strip entry temperature ;

[0010] Step (3): define the constraint parameters of the relevant shape of the plate:

[0011] define the maximum rolling pressure of any rack , maximum rolling power , slip factor to maintain stability , hot scratch index ; define the maximum speed V, total reduction H; define the initial target value ; thermal work equivalent ; the influence coefficient of the roughness of the work roll surface and the strip surface , take 0.09~0.15;

[0012] Step (4): establish a model of each influencing factor of the tinplate in the cold rolling process;

[0013] Step (5): fine optimization of the reduction distribution coefficient;

[0014] Step (6): output the optimal value of the reduction distribution between the first cold rolling and the quasi-second cold rolling.

[0015] The further improvement of the above scheme is that: the step (4) specifically includes the following steps:

[0016] Step (41): calculate the rolling pressure of the kth cold rolling machine stand :

[0017] ;

[0018] In the formula, is the equivalent tension influence coefficient, is the external friction influence coefficient, is the Poisson's ratio of the strip, is the Poisson's ratio Young's modulus of the strip, is the friction coefficient between the rollers of the rack and the strip, p is the total rolling pressure, is the reduction rate, subscript k is the unit number, k=1 is the first cold rolling unit, k=2 is the second cold rolling unit;

[0019] Step (42): calculate the rolling power of the kth cold rolling machine stand :

[0020] ;

[0021] wherein, is the rolling torque;

[0022] Step (43): calculating the target function of the i-th stand of the k-th cold rolling slip factor of the stand :

[0023] ;

[0024] wherein, is the friction coefficient between the roll and the strip of the i-th stand of the k-th cold rolling mill train, is the reduction of the i-th stand of the k-th cold rolling mill train, is the flattening radius of the roll of the i-th stand of the k-th cold rolling mill train, is the entry tension of the i-th stand of the k-th cold rolling mill train, is the exit tension of the i-th stand of the k-th cold rolling mill train, is the rolling pressure of the i-th stand of the k-th cold rolling mill train;

[0025] Step (44): calculating the hot galling index of the i-th stand of the k-th cold rolling slip factor of the stand :

[0026] ;

[0027] wherein, is the critical oil film thickness, is the lubricant concentration influence coefficient, is the viscosity compression coefficient of the lubricant in the deformation zone, is the dynamic viscosity, is the surface roughness of the roll of the stand, is the surface roughness of the strip, is the specific heat capacity of the strip, is the bite angle;

[0028] Step (45): calculating the target function of the k-th cold rolling :

[0029] establishing the target function of the i-th stand of the k-th cold rolling mill train: : ;

[0030] wherein, is the rolling pressure ratio influence coefficient, is the rolling power ratio influence coefficient, is the slip factor ratio influence coefficient, is the hot galling index ratio influence coefficient, ;

[0031] establishing a quasi-secondary cold rolling mill set frame target function:

[0032] .

[0033] The further improvement of the above scheme is that the step (5) specifically comprises the following steps:

[0034] Step (51): according to the comprehensive reduction distribution coefficient determine the constraint range that the total reduction distribution of the primary cold rolling mill set and the quasi-secondary cold rolling mill set needs to meet;

[0035] ;

[0036] Step (52): take the minimum set value ; ;

[0037] Step (53): set the initial value ;

[0038] Step (54): take a reasonable step size =0.001;

[0039] Step (55): let the subscript ;

[0040] Step (56): calculate the target function of cold rolling :

[0041] ;

[0042] In the formula, is the weighting coefficient of the primary cold rolling and the secondary cold rolling, which is taken as ;

[0043] Step (57): judge whether the inequality is established, if it is established, let , and go to the next step, otherwise directly go to the next step;

[0044] Step (58): judge whether the inequality is established, if it is established, let the subscript and , go to step (56), otherwise directly go to the next step;

[0045] (59) output the optimal solution of .

[0046] The further improvement of the above scheme is that the equivalent tension influence coefficient ; strip poisson's ratio ; strip poisson's ratio young's modulus ; lubricant concentration influence coefficient ; lubricant viscosity compressibility coefficient in deformation zone ; dynamic viscosity ; bite angle ; critical oil film thickness .

[0047] The present application provides a method for distributing the reduction between the first cold rolling and the quasi-second cold rolling, based on the strength index of the hot rolling material and the strength index of the finished strip, under the premise that the reduction distribution domain between the first cold rolling and the quasi-second cold rolling meets the mechanical property requirements of the finished strip, the distribution of the reduction between the first cold rolling and the quasi-second cold rolling is ensured to realize the key quality index and stable rolling of the cold rolling mill. After using the method for distributing the reduction between the first cold rolling and the quasi-second cold rolling provided by the present application, the reduction between the first cold rolling and the quasi-second cold rolling can be accurately distributed, the production capacity of the mill can be increased by more than 5%, the defect closure rate can be reduced by more than 10%, and the annual economic benefits can exceed 2 million yuan. DETAILED DESCRIPTION

[0048] EMBODIMENT

[0049] The method for distributing the reduction between the first cold rolling and the quasi-second cold rolling of the present embodiment first collects the equipment parameters of the cold rolling mill in step (1), mainly including: the R roll radius of each stand of the first cold rolling and the second cold rolling, the roll speed, the motor efficiency, the work roll surface roughness.

[0050] Table 1 Equipment parameters of the cold rolling mill

[0051]

[0052] Then in step (2), the key rolling process parameters of the strip to be controlled for flatness and crown are collected, mainly including: the average deformation resistance of each stand of the first cold rolling and the second cold rolling, the width of the strip, the strip inlet thickness, the inlet tension, the outlet tension, the strip inlet speed, the back tension stress, the strip density, the strip inlet temperature.

[0053] Table 2 Key rolling process parameters of the strip for flatness and crown

[0054]

[0055] Then in step (3), define the relevant plate shape control parameters, define the initial target value.

[0056] Define the maximum rolling pressure of any stand , the maximum rolling power , the stable slip factor , the hot scratch index , define the maximum speed V, the total reduction H. Define the initial target value , let ; thermal equivalent power , take ; the influence coefficient of the work roll surface and the strip surface roughness , take 0.10;

[0057] Then in step (4), establish a model of each influencing factor of tinplate in the cold rolling process;

[0058] Then in step (41), calculate the rolling pressure of the kth cold rolling of the stand :

[0059] ;

[0060] Then in step (42), calculate the rolling power of the kth cold rolling of the stand

[0061] ;

[0062] Then in step (43), calculate the slip factor of the kth cold rolling of the stand :

[0063] ;

[0064] Then in step (44), calculate the hot scratch index of the kth cold rolling of the stand :

[0065] ;

[0066] Then in step (45), calculate the target function of the kth cold rolling :

[0067] ;

[0068] ;

[0069] Subsequently, in step (5), the pressure distribution coefficient is finely optimized.

[0070] Subsequently, in step (51), based on the comprehensive compression distribution coefficient... Determine the constraint range that the total reduction distribution between the primary cold rolling mill and the quasi-secondary cold rolling mill must meet;

[0071] ;

[0072] Then in step (52), Pick Minimum setting value ;

[0073] Then in step (53), an initial value is set. ;

[0074] Then, in step (54), a reasonable step size is selected. ;

[0075] Then in step (55), let ;

[0076] Subsequently, in step (56), the objective function for cold rolling is calculated. :

[0077] ;

[0078] Then in step (57), the inequality is determined. Is it true? If true, then let If the condition is met, proceed to step (58); otherwise, proceed directly to step (58).

[0079] Then in step (58), the inequality is determined. Is it true? If true, then let and If the condition is met, proceed to step (56); otherwise, proceed directly to step (59).

[0080] Then in step (59), the output is... optimal solution .

[0081] Subsequently, in step (6), the optimal value for the reduction distribution between the primary cold rolling and quasi-secondary cold rolling of the tinplate is output;

[0082] Finally, in step (7), the design of the reduction distribution method between the first cold rolling and the quasi-second cold rolling of tinplate is completed.

[0083] Example 2:

[0084] First, in step (1), the equipment parameters of the cold rolling mill are collected, mainly including: the R-roll radius of each stand in the primary and secondary cold rolling mills, Roll speed, Motor efficiency, Surface roughness of the work roll.

[0085] Table 1 Equipment parameters of the cold rolling mill

[0086]

[0087] Subsequently, in step (2), the key rolling process parameters of the strip steel with the shape and crown to be controlled are collected, mainly including: the parameters of each stand in the primary and secondary cold rolling mills. Average deformation resistance, The width of the strip, Strip entry thickness, Inlet tension, Export tension, Strip entry speed, Post-tension stress, strip density, Strip inlet temperature.

[0088] Table 2 Key rolling process parameters for strip with shape and crown

[0089]

[0090] Subsequently, in step (3), the relevant plate shape control parameters are defined, and the initial target value is defined.

[0091] Define the maximum rolling pressure for any stand. Maximum rolling power Maintain a stable slip factor Hot Slip Injury Index Define the maximum speed V and the total pressure reduction H. Define the initial target value. ,make Mechanical Equivalent of Heat ,Pick ; Influence coefficient of roughness between work roll surface and strip surface Take 0.10;

[0092] Subsequently, in step (4), a model of the influencing factors of tinplate during the cold rolling process is established.

[0093] Subsequently, in step (41), the k-th cold rolling is calculated. Rolling pressure of the stand :

[0094] ;

[0095] Then in step (42), the first Rolling power of the housing

[0096] ;

[0097] Then in step (43), the first Slip factor of the housing :

[0098] ;

[0099] Then in step (44), the first Hot slip mark index of the housing :

[0100] ;

[0101] Then in step (45), the target function of the kth cold rolling :

[0102] ;

[0103] ;

[0104] Then in step (5), the reduction distribution coefficient is finely optimized

[0105] Then in step (51), according to the comprehensive reduction distribution coefficient The constraint range that the total reduction distribution of the primary cold rolling mill set and the quasi-secondary cold rolling mill set needs to meet is determined;

[0106] ;

[0107] Then in step (52), the minimum set value is taken ;

[0108] Then in step (53), the initial value is set ;

[0109] Then in step (54), a reasonable step size is taken ;

[0110] Then in step (55), let ;

[0111] Then in step (56), the target function of the cold rolling is calculated :

[0112] ​​ ;

[0113] Subsequently in step (57), judge whether the inequality is established? If yes, let , turn into step (58), otherwise directly turn into step (58);

[0114] Subsequently in step (58), judge whether the inequality is established? If yes, let and , turn into step (56), otherwise directly turn into step (59);

[0115] Subsequently in step (59), output the optimal solution of .

[0116] Subsequently in step (6), output the optimal value of the reduction distribution between the primary cold rolling and the quasi-secondary cold rolling of the tinplate;

[0117] Finally in step (7), complete the design of the reduction distribution method between the primary cold rolling and the quasi-secondary cold rolling of the tinplate.

[0118] The present application is not limited to the above-mentioned embodiments. Any technical solution formed by equivalent replacement falls within the scope of protection required by the present application.

Claims

1. A method of distributing reductions between a first cold rolling and a quasi- second cold rolling, characterized in that, It comprises the following steps: Step (1): obtaining the equipment parameters of the cold rolling mill set: Rolling mill radius R, rolling mill speed , motor efficiency , work roll linear speed , work roll surface roughness ; Step (2): obtaining the rolling process parameters: average deformation resistance of each stand of a cold rolling mill , width B of the strip, strip entry thickness , strip exit thickness , reduction , entry tension , exit tension , strip entry speed , and strip deformation resistance , back tension stress , strip density , strip entry temperature ; Step (3): defining the constraint parameters of the related plate shape: Defining the maximum rolling force of an arbitrary stand , the maximum rolling power , the stable slip factor , the hot galling index ; defining the maximum speed V, the total reduction H; defining the initial target value ; Thermal work equivalent ; work roll surface and strip surface roughness influence coefficient , take 0.09~0.15; Step (4): establishing the model of each influencing factor of the tinplate in the cold rolling process; Step (5): fine optimization of the reduction distribution coefficient; Step (6): outputting the optimal value of the reduction distribution between the primary cold rolling and the quasi-secondary cold rolling; The step (4) specifically comprises the following steps: Step (41): calculating the thickness of the k-th cold-rolled sheet Rolling pressure of the stand : ； wherein, is the equivalent tension influence coefficient, is the outer friction influence coefficient, is the strip Poisson's ratio, is the strip Poisson's ratio Young's modulus, is the friction coefficient between the rollers of the stand and the strip, p is the total rolling pressure, is the reduction, the subscript k is the sequence number of the stand, k = 1 for the first cold rolling stand and k = 2 for the second cold rolling stand; Step (42): calculating the thickness of the k-th cold-rolled sheet Rolling power of the stand : ； In the formula, is the rolling torque; Step (43): calculating the thickness of the k-th cold-rolled sheet Slip factor of the rack : ； wherein, is the friction coefficient between the roll and the strip in the i-th stand of the k-th cold rolling train, is the reduction in the i-th stand of the k-th cold rolling train, is the flattening radius of the roll in the i-th stand of the k-th cold rolling train, is the entry tension in the i-th stand of the k-th cold rolling train, is the exit tension in the i-th stand of the k-th cold rolling train, is the rolling pressure in the i-th stand of the k-th cold rolling train. Step (44): calculating the k-th cold-rolled first hot streak index of the rack : ； wherein C is the critical oil film thickness, C is the lubricant concentration influence coefficient, C is the viscosity compressibility coefficient of the lubricant in the deformation zone, C is the dynamic viscosity, C is the surface roughness of the rolls of the stand, C is the surface roughness of the strip, C is the specific heat capacity of the strip, C is the bite angle; Step (45): calculating the objective function for the kth cold rolling : Establishing a first cold rolling mill set Rack target function: ​ wherein is the rolling pressure ratio influence coefficient, is the rolling power ratio influence coefficient, is the slip factor ratio influence coefficient, is the hot galling index ratio influence coefficient, ; Establishing the quasi-quadratic cold rolling mill set Rack target function: ； The step (5) specifically comprises the following steps: Step (51): determining the integrated reduction distribution coefficient according to the constraint range determining the constraint range that the total reduction distribution of the primary cold rolling mill train and the quasi-secondary cold rolling mill train needs to satisfy; ； Step (52): Take The minimum set value ; Step (53): Set initial value ; Step (54): Take reasonable step = 0.001; Step (55): let the index ; Step (56): calculating the target function for cold rolling : ； In the formula, is a weighting coefficient for the first cold rolling and the second cold rolling, ; Step (57): Determine the inequality Is it true? If it is true, then let... Proceed to the next step if necessary; otherwise, proceed directly to the next step. Step (58): judging whether the inequality holds, if yes, let the subscript and and , go to step (56), otherwise go to the next step directly; (59) output of the optimal solution.

2. A method of distributing the reduction between the first cold rolling and the quasi- second cold rolling according to claim 1, characterized in that: Equivalent tension influence coefficient Poisson's ratio of the strip Young's modulus of the strip Concentration influence coefficient of the lubricant Viscosity compression coefficient of the lubricant in the deformation zone ; Dynamic viscosity ; bite angle ; critical oil film thickness .

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