Method for controlling the width of a wedge-shaped strip based on a large side pressure device

Abstract

The application discloses a wedge-shaped strip steel width control method based on a large side pressure device, which comprises the following steps: firstly, taking the width of one end of the wedge-shaped strip steel as a reference, calculating the width load distribution, and taking the first pass outlet width target as the first pass target width of the other end on the basis of keeping the roll gap value of the vertical roll constant, calculating the SP pressure; if there is no solution, taking the other end as the reference and repeating the above calculation; then, according to the SP pressure of the large and small end parts, the strip steel is rolled by changing the roll gap in the full length through the large side pressure device, and the rectangular strip steel is obtained after the pass rolling. The application avoids the problem that the wedge-shaped blank becomes inverted wedge-shaped after passing through the large side pressure when the roll gap of the vertical roll is constant, the E1 pressure of the first pass of the vertical roll is different, and fully utilizes the width adjusting capacity of the large side pressure device, and the width control precision of the wedge-shaped blank is improved.

Description

Technical Field

[0001] This invention relates to a quality control method for strip steel production, and more particularly to a method for controlling the width of wedge-shaped strip steel based on a large side-pressure equipment. Background Technology

[0002] The raw material for hot-rolled strip steel production is generally continuously cast billets. During the continuous casting stage, online width adjustment technology is used to improve production efficiency. In this process, due to numerous factors affecting width, wedge-shaped billets frequently appear (accounting for approximately 10%). This necessitates the use of width adjustment equipment to control the strip width along its entire length. A wedge-shaped billet consists of three sections: a rectangular head section, a trapezoidal middle section, and a rectangular tail section. Currently, width adjustment for wedge-shaped billets is mostly achieved using vertical rolls. However, the width adjustment capacity of vertical rolls is limited, and they cannot effectively control strips with severe wedge-like shapes.

[0003] Chinese invention patent ZL201610141279.4 discloses a method for controlling the width of a wedge billet based on a constant-width side press. This method divides the wedge billet into three segments according to its width variation pattern, calculates the dog-bone width of the equal-width head and tail segments to correct the compression amount, then calculates the number of steps and the step amount based on the corrected compression amount, and finally interpolates to calculate the compression amount of each step in the variable-width segment. This patent mainly uses the SP model to calculate the dog-bone width of the wedge billet's head and tail to solve the wedge billet problem. However, it does not consider the difference in dog-bone width caused by the different compression of the large and small ends of the wedge billet when the vertical roll gap is constant, nor the benchmark problem of width load distribution. This leads to the possibility that the method may be unsolvable and its application scope is limited.

[0004] Chinese invention patent ZL201210211053.9 discloses a method for controlling the width of hot-rolled wedge-shaped slabs. This method determines the type of wedge-shaped slab based on the head-to-tail width difference of the incoming strip before it enters the roughing mill. Then, based on the wedge-shaped slab type, the width of the wedge-shaped slab is controlled within multiple stands of the roughing mill. This patent primarily classifies and controls slabs with different wedge shapes, dividing the wedge shape into three levels: less than 20mm, 20-40mm, and more than 40mm. Different short-stroke and long-stroke control strategies are selected for different wedge shapes to achieve strip width control. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the width of wedge strip based on a large side-pressure equipment. This method can utilize the width adjustment capability of the large side-pressure equipment to keep the roll gap of each forward pass constant, thereby ultimately achieving width control of hot-rolled wedge strip.

[0006] This invention is implemented as follows:

[0007] A method for controlling the width of wedge-shaped strip steel based on a large lateral pressure device includes the following steps:

[0008] Step 1: Calculate the horizontal roll thickness load distribution to determine the target strip width W at the roughing mill exit for this pass. Target ;

[0009] Step 2: Determine whether the incoming strip steel is a wedge-shaped billet. If not, proceed to step 3; if yes, proceed to step 4.

[0010] Step 3: Based on the width of the incoming strip, call the width load distribution model. SP calculates the maximum side pressure reduction based on the width load distribution model and controls the width of the incoming strip for this pass with a constant roll gap. Proceed to step 9.

[0011] Step 4: Using the large head portion as a reference, call the width load distribution model, keep the target width of the strip at the roughing exit of this pass, keep the roll gap of E1 unchanged in this pass, and calculate the SP reduction of the large head portion and the SP reduction of the small head portion.

[0012] Step 5: Based on the SP reduction amount of the large end and the SP reduction amount of the small end calculated in Step 4, the SP model determines whether the width adjustment condition based on the small end is met. If not, proceed to Step 6; if yes, proceed to Step 7.

[0013] Step 6: Based on the SP reduction amount of the large end and the SP reduction amount of the small end calculated in Step 4, the SP model controls the SP full-length variable roll gap rolling of the strip steel, and proceeds to Step 9.

[0014] Step 7: Using the small head as a reference, call the width load distribution model, keep the target width of the strip at the exit of the roughing mill in the pass, keep the roll gap of E1 unchanged in this pass, and calculate the SP reduction of the small head and the SP reduction of the large head.

[0015] Step 8: Based on the SP reduction amount of the large end and the SP reduction amount of the small end calculated in Step 7, control the SP full-length variable roll gap rolling of the strip.

[0016] Step 9: Complete the rough rolling of this pass to obtain a rectangular strip.

[0017] In step 4, the calculation method for the SP reduction amount of the small-head portion is as follows:

[0018] If the incoming steel strip with the wedge-shaped section passes through SP, E1, and R1 in sequence, then the following formula holds:

[0019] W R11Target =W Big -dW SPBig -dW E11Big +dW R11Spread+dW SPDogBig +dW E11DogBig (1)

[0020] W E11Exit =W Big -dW SPBig -dW E11Big (2)

[0021] Among them, W R11Target The exit target width for the first pass of R1 in the large section is based on this, and the exit target width for the first pass of R1 in the small section is also based on this.

[0022] dW SPBig This represents the SP reduction amount of the bulk portion in this pass;

[0023] dW E11Big This refers to the reduction amount in the first pass of the E1 section, which is the bulk part.

[0024] dW R11Spread The horizontal width of the first pass in the R1 section is extended;

[0025] dW SPDogBig The dog bone of the large head part of SP is widened;

[0026] dW E11DogBig The dogbone of the first pass in E1 is widened for the main head section;

[0027] W E11Exit The exit width of the first pass of E1 in the large head section is the E1 roll gap value when the large head section is used as the reference for width adjustment.

[0028] The exit target width of the small-head portion in the first pass of R1 is the same as the exit target width of the large-head portion in the first pass of R1, i.e., W. R11Target As a benchmark, and assuming that the E1 roll gap value of the small end remains unchanged in the first pass of E1, then the following formula holds:

[0029] W R11Target =W Small -dW SPSmall -dW E11Small +dW R11Spread +dW SPDogSmall +dW E11DogSmall (3)

[0030] W E11Exit =W Big -dW SPBig -dW E11Big =W Small -dW SPSmall -dW E11Small (4)

[0031] Among them, dWSPSmall This represents the SP reduction amount of the small end portion in this pass.

[0032] dW E11Small This refers to the E1 reduction amount in the first pass of the small-head portion E1.

[0033] dW R11Spread The horizontal width of the first pass of the small-head portion R1 is expanded.

[0034] dW SPDogSmall The small head portion is widened in this lane's SP dog bone.

[0035] dW E11DogSmall For the small head portion, E1, the first pass of the dog bone is widened;

[0036] As can be seen from equation (4), when adjusting the width of the small head portion by SP, the total SP reduction of the small head portion in that pass is fixed, and the total E1 reduction of the small head portion in that pass is fixed.

[0037] Let dW E11Small The initial value is dW E11Big The size is increased in 2mm increments, and Newton's method of truncating chords is used to determine the inlet width W of the small end. Small The E1 reduction amount dW in the first pass of the small-head section E1 E11Small The R1 reduction amount in the first pass of the small-head section R1 and the target exit width W of that pass. R11Target Calculate dW SPSmall And stop iterating when inequality (5) holds;

[0038] |W Small -W E11Exit -dW SPSmall -dW E11Small |≤2mm (5).

[0039] The horizontally widened model is: dW Spread =f(W e ,h0,h1,T);

[0040] Where h0 is the inlet thickness of R1, h1 is the strip outlet thickness of R1, T is the inlet temperature of R1, and W... e This is the exit width after E1 rolling, which is the inlet width of R1.

[0041] The exit width W after E1 rolling e The model is: W e =W0-dW SP -dW Edger ;

[0042] Where W0 is the width of the incoming strip steel, dWSP SP reduction, dW Edger E1 compression amount.

[0043] The model for the dog bone width of the SP is: dW SPDog =f(dW SP ).

[0044] The model for the dog bone width of E1 is: dW EdgerDog =f(W1,W e ,h0,R), where W1 is the strip width before E1 lateral pressure, W1=W0-dW SP R is the radius of R1.

[0045] In step 5, the width adjustment conditions based on the small end include:

[0046] (I) The small-head portion passes through SP in this pass; when dW SPSmall When the value is 0, the smaller part passes through SP in that pass.

[0047] (II) E1 first pass load is full; when dW E11Small = When the maximum reduction of E1 in the first pass is reached, the load of E1 in the first pass is full.

[0048] When the above conditions (I) or (II) are met, there is no solution for width adjustment based on the larger end, so the width adjustment is switched to the smaller end as the basis, i.e., step 7 is executed.

[0049] In step 7, the calculation method for the SP reduction amount of the small-head portion is as follows:

[0050] If the incoming steel strip with the wedge-shaped section passes through SP, E1, and R1 in sequence, then the following formula holds:

[0051] W R11Target =W Small -dW SPSmall -dW E11Small +dW R11Spread +dW SPDogSmall +dW E11DogSmall (6)

[0052] W E11Exit =W small -dW SPSmall -dW E11Small (7)

[0053] Among them, W R11Target The exit target width for the first pass of R1 in the small head section is based on this, and the exit target width for the first pass of R1 in the large head section is also based on this.

[0054] dW SPSmallThis represents the SP reduction amount of the small end portion in this pass;

[0055] dW E11Small This refers to the E1 reduction amount in the first pass of the small-head portion;

[0056] dW R11Spread For the small-head portion, R1 is the horizontal width of the first pass;

[0057] dW SPDogSmall The dog bone of the small head portion SP is widened;

[0058] dW E11DogSmall For the small head portion, E1, the first pass of the dog bone is widened;

[0059] W E11Exit This is the exit width of the small end portion in the first pass of E1, i.e., the E1 roll gap value;

[0060] The target exit width of the larger portion in the first pass of R1 is based on the target exit width of the smaller portion in the first pass of R1. Meanwhile, the E1 roll gap value of the larger portion remains unchanged in this pass. Therefore, the following formula holds:

[0061] W R11Target =W Big -dW SPBig -dW E11Big +dW R11Spread +dW SPDogBig +dW E11DogBig (8)

[0062] W E11Exit =W Small -dW SPSmall -dW E11Small ≤W Big -dW SPBig -dW E11Big (9)

[0063] Among them, dW SPBig This represents the SP reduction amount of the bulk portion in this pass;

[0064] dW E11Big This refers to the E1 reduction amount in the first pass of the E1 section of the large portion;

[0065] dW SPDogBig The main part of the SP dog bone in this track is widened;

[0066] dW E11DogBig The dogbone of the first pass in E1 is widened for the main head section;

[0067] As can be seen from equation (9), with the small head as the benchmark, when adjusting the width using SP, the total SP reduction of the large head portion in that pass is fixed, the total E1 reduction of the large head portion in that pass is fixed, and at this time dW E11Big ≠0;

[0068] Let dW E11Big The initial value is dW E11Small Decrease the length in increments of 2mm down to 0, using Newton's method of truncated chords, based on the entrance width W of the larger section. Big E1 reduction amount dW of the large end section E11Big The R1 reduction of the large end portion and the target exit width W of this pass. R11Target Calculate dW SPBig And stop iterating when one of the following conditions is met:

[0069] (III)dW E11Big ≠0 and inequality (10) holds:

[0070] |W Big -W E11Exit -dW SPBig -dW E11Big |≤2mm (10);

[0071] (IV)dW E11Big =0.

[0072] In steps 6 and 8, during the SP full-length variable roll gap rolling process, for the head section of the wedge billet, the width before SP side pressing is the width of the billet head; for the tail section of the wedge billet, the width before SP side pressing is the width of the billet tail; and for the trapezoidal middle section of the wedge billet, the width before SP side pressing is calculated from the linear difference between the billet head width and the billet tail width.

[0073] The reduction amounts for each step of SP on the wedge blank are as follows: head reduction amount dW of the head section. SPHead Tail section tail compression amount dW SPTail And the middle section's reduction amount dW SPBody ;

[0074] Middle reduction dW SPBody The calculation formula is:

[0075]

[0076] Among them, cL body The total length of the width-adjusted section of the incoming strip steel;

[0077] sL is the cumulative length from the starting point of the strip width adjustment to the SP pressing position.

[0078] Compared with the prior art, the present invention has the following beneficial effects:

[0079] 1. This invention is based on the width adjustment capability of the SP of the large side-pressure equipment. First, the width of the large end of the strip is used as a reference. According to the target width of roughing, the target width of each forward pass and the load distribution of the vertical roll are calculated. Then, according to the target width of the first pass and the width of the small end of the strip, the roll gap value of the first pass of the vertical roll is kept constant, and the SP reduction and E1 reduction of the small end are calculated iteratively. If there is no solution, it is converted to use the small end as a reference and the above process is repeated. Then, the SP full-length variable roll gap rolling is controlled according to the SP reduction of the large and small ends to realize the hot rolling width control of the strip. It can effectively improve the width control effect of the wedge billet and realize the rectangular control of the strip at the exit of the first pass of the horizontal roll.

[0080] 2. This invention simplifies the process of controlling the width of wedge strip steel, realizes dynamic width adjustment of wedge billet, and can effectively improve the width quality of wedge billet rolling.

[0081] This invention uses the width of one end of the wedge strip as a reference to calculate the width load distribution. While keeping the vertical roll gap value constant, it uses the target width of the first pass exit as the target width of the first pass on the other side to calculate the reduction of SP. If there is no solution, the other end is replaced as the reference and the above calculation is repeated. This avoids the problem that the wedge blank becomes an inverted wedge after large side pressure when the vertical roll gap is constant, resulting in different E1 reductions in the first pass of the vertical roll. It also makes full use of the width adjustment capability of the large side pressure equipment to improve the width control accuracy of the wedge blank. Attached Figure Description

[0082] Figure 1 This is a flowchart of the wedge strip width control method based on a large lateral pressure device according to the present invention;

[0083] Figure 2 This invention relates to the shape change process of the incoming strip width in the wedge strip width control method based on large side pressure equipment;

[0084] Figure 3 This is the R1 first pass exit width curve of the strip in an embodiment of the wedge strip width control method based on a large side pressure equipment of the present invention. Detailed Implementation

[0085] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0086] Please see the appendix Figure 1A method for controlling the width of wedge strip based on a large side-pressure device is proposed. This method is applied to a hot rolling production line, which is equipped with a large side-pressure device (hereinafter referred to as SP), a first vertical roll (hereinafter referred to as E1), a first horizontal roll (hereinafter referred to as R1), a second vertical roll (hereinafter referred to as E2), and a second horizontal roll (hereinafter referred to as R2). After determining the target width of the strip at the roughing mill exit, SP, E1, R1, E2, and R2 can determine the target width of each forward pass based on the information of the incoming strip and perform width load distribution.

[0087] The method for controlling the width of wedge-shaped strip steel based on large lateral pressure equipment includes the following steps:

[0088] Step 1: Calculate the horizontal roll thickness load distribution to determine the target strip width W at the roughing mill exit for this pass. Target .

[0089] The thickness load distribution of the horizontal roll can be achieved using the thickness load distribution model of the production system. Based on information such as the incoming strip thickness, the intermediate billet thickness (given by the strip thickness at the roughing mill exit and the process specification table), the total number of rolling passes of the horizontal roll, and the relative reduction rate of each pass of the horizontal roll, the thickness reduction of each pass of the horizontal roll is calculated. The thickness load distribution model is a general module and will not be elaborated here.

[0090] Based on the target width of the finishing mill, and taking into account the finishing mill allowance, the thermal expansion of the strip, and the predicted natural width expansion of the finishing mill, the target width W of the strip at the roughing mill exit is determined. Target .

[0091] Step 2: Determine if the incoming strip is a wedge-shaped billet. If not, proceed to Step 3; if yes, proceed to Step 4. The wedge-shaped billet can be determined using the strip rolling plan data (PDI). The PDI includes the head width and tail width data of the incoming strip. If the difference between the head width and tail width exceeds 20mm, it is a wedge-shaped billet. The PDI also includes the start and end positions of the wedge shape.

[0092] The wedge-shaped billet consists of three sections: a rectangular head section, a trapezoidal middle section, and a rectangular tail section. According to the rolling direction of the incoming strip, if the larger end of the strip is in front and the smaller end is behind, then the width W of the strip head... Head That is, W Big The reduction amount dW at the head of the strip by the large side-pressure equipment (hereinafter referred to as SP) SPHead That is, dW SPBig The width W of the strip tail Tail That is, W Small SP's reduction amount dW at the tail of the strip SPTail That is, dW SPSmallConversely, if the smaller end of the incoming strip is in front and the larger end is behind, then the strip head width W... Head That is, W Small SP's reduction amount dW at the strip head SPHead That is, dW SPSmall The width W of the strip tail Tail That is, W Big SP's reduction amount dW at the tail of the strip SPTail That is, dW SPBig .

[0093] Step 3: Based on the width of the incoming strip, call the width load distribution model. SP uses the large side pressure reduction (hereinafter referred to as SP reduction) calculated by the width load distribution model to control the width of the incoming strip in this pass with a constant roll gap, and then proceed to step 9.

[0094] Width control of non-wedge billets through rough rolling is a conventional production process and will not be elaborated here.

[0095] Step 4: First, using the large head portion as a benchmark, call the width load distribution model to maintain the target width W of the strip at the roughing mill exit for this pass. R11Target E1 remains constant in this pass, calculate the SP reduction of the small end and the SP reduction of the large end.

[0096] In practice, calculations can be performed based on the small head portion as a reference, and then converted to the large head portion as a reference when there is no solution for the SP compression amount in the small head portion.

[0097] If the incoming steel strip with the wedge-shaped section passes through SP, E1, and R1 in sequence, then the following formula holds:

[0098] W R11Target =W Big -dW SPBig -dW E11Big +dW R11Spread +dW SPDogBig +dW E11DogBig (1)

[0099] W E11Exit =W Big -dW SPBig -dW E11Big (2)

[0100] Among them, W R11Target The exit target width for the first pass of R1 in the large head section is based on this, and the exit target width for the first pass of R1 in the small head section is also based on this.

[0101] dW SPBig This refers to the SP reduction amount for the larger section in this pass. It is based on the width W of the larger section of the incoming strip.Big The thickness reduction of the horizontal roll in each pass and the target width W of the strip at the roughing mill exit, calculated in step 1. Target By calling the width load distribution model, the SP reduction amount dW in the large-head portion can be obtained. SPBig E1 reduction for each forward pass (including the E1 reduction dW for the first pass) E11Big Reverse pass vertical roller empty), R11 exit width (i.e., target exit width W) R11Target ).

[0102] dW E11Big This refers to the reduction amount in the first pass of the E1 section, which is the bulk part.

[0103] dW R11Spread The horizontal width of the first pass of R1 is the main part.

[0104] The horizontally widened model is dW Spread =f(W e (h0, h1, T), where h0 is the inlet thickness of R1, h1 is the outlet thickness of the strip of R1, T is the inlet temperature of R1, and W... e This is the exit width after E1 rolling, which is the inlet width of R1.

[0105] W e The model is: W e =W0-dW SP -dW Edger Where W0 is the width of the incoming strip, dW SP SP reduction, dW Edger E1 is the reduction amount. When rolling the large end portion, W0 is the width of the large end portion, and dW SP dW represents the SP reduction amount of the larger section. Edger E1 represents the reduction amount of the larger end portion; conversely, when rolling the smaller end portion, W0 represents the width of the smaller end portion, dW SP dW represents the SP reduction amount of the small end portion. Edger E1 is the amount of pressure applied to the small end.

[0106] dW SPDogBig The dog-bone extension of the large head portion SP is modeled as: dW SPDog =f(dW SP ).

[0107] dW E11DogBig For the dogbone extension of the first pass in the E1 section, the model for the dogbone extension of E1 is: dW EdgerDog =f(W1,W e ,h0,R), where W1 is the strip width before E1 lateral pressure, W1=W0-dWSP R is the radius of R1.

[0108] dW Dog The dog bone width after horizontal rolling includes the dog bone width of SP and the dog bone width of E1, i.e., dW. Dog =dW SPDog +dW EdgerDog .

[0109] W E11Exit E1 represents the exit width of the large end portion in the first pass, i.e., the E1 roll gap value when adjusting the width based on the large end portion. For wedge-shaped billets, when calculating the SP reduction of the small end portion, the E1 roll gap value is kept constant, and the width is adjusted using SP. Therefore, the E1 roll gap value of the small end portion remains unchanged in this pass.

[0110] The exit target width of the small-head portion in the first pass of R1 is the same as the exit target width of the large-head portion in the first pass of R1, i.e., W. R11Target Based on this, and with the E1 roll gap value remaining constant in the first pass (E1) for the smaller end portion, the wedge-shaped strip becomes an inverted wedge shape after being rolled using the variable roll gap (SP). That is, a wedge-shaped billet with the larger end in front and the smaller end behind becomes an inverted wedge-shaped billet with the smaller end in front and the larger end behind after being rolled using the variable roll gap (SP). Conversely, a wedge-shaped billet with the smaller end in front and the larger end behind becomes an inverted wedge-shaped billet with the larger end in front and the smaller end behind after being rolled using the variable roll gap (SP). Therefore, the SP reduction for the smaller end portion is less than the SP reduction for the larger end portion, while the E1 reduction for the smaller end portion is greater than the E1 reduction for the larger end portion. Thus, the following formula holds:

[0111] W R11Target =W Small -dW SPSmall -dW E11Small +dW R11Spread +dW SPDogSmall +dW E11DogSmall (3)

[0112] W E11Exit =W Big -dW SPBig -dW E11Big =W Small -dW SPSmall -dW E11Small (4)

[0113] Among them, dW SPSmall This represents the SP reduction amount of the small end portion in this pass.

[0114] dW E11Small This refers to the E1 reduction amount in the first pass of the small-head portion E1.

[0115] dW R11Spread The horizontal width of the first pass of the small-head portion R1 is expanded.

[0116] dW SPDogSmall The small head portion is widened in this lane's SP dog bone.

[0117] dW E11DogSmall The dog bone is widened for the first pass of the E1 section of the small head.

[0118] As can be seen from equation (4), when adjusting the width of the small head portion by SP, the total SP reduction of the small head portion in that pass is fixed, and the total E1 reduction of the small head portion in that pass is fixed.

[0119] Let dW E11Small The initial value is dW E11Big The size is increased in 2mm increments, and Newton's method of truncating chords is used to determine the inlet width W of the small end. Small The E1 reduction amount dW in the first pass of the small-head section E1 E11Small The R1 reduction amount in the first pass of the small-head section R1 and the target exit width W of that pass. R11Target Calculate dW SPSmall The iteration stops when inequality (5) is satisfied.

[0120] |W Small -W E11Exit -dW SPSmall -dW E11Small |≤2mm (5).

[0121] Step 5: The SP model calculates the SP reduction amount dW of the large-head portion based on the calculation in Step 4. SPBig SP reduction amount dW of the small end portion SPSmall Determine whether the width adjustment condition based on the smaller end is met. If not, proceed to step 6; if yes, proceed to step 7.

[0122] The width adjustment conditions based on the small end include:

[0123] (I) The small end passes through SP in this pass. When dW SPSmall When the value is 0, the smaller part passes through SP in that pass.

[0124] (II) E1 first pass load is full. When dW E11Small = When the maximum reduction of E1 in the first pass is reached, the load of E1 in the first pass is full.

[0125] When the above conditions (I) or (II) are met, there is no solution for width adjustment based on the larger end, so the width adjustment is switched to the smaller end as the basis, i.e., step 7 is executed.

[0126] Step 6: The SP model calculates the SP reduction dW of the large-head portion based on the calculation in Step 4. SPBigSP reduction amount dW of the small end portion SPSmall Control the SP full-length variable roll gap rolling strip and proceed to step 9.

[0127] Step 7: Using the small head as a reference, call the width load distribution model to maintain the target width W of the strip at the exit of the roughing mill. R1Target E1 remains constant in this pass, calculate the SP reduction of the small end and the SP reduction of the large end.

[0128] If the incoming steel strip with the wedge-shaped section passes through SP, E1, and R1 in sequence, then the following formula holds:

[0129] W R11Target =W Small -dW SPSmall -dW E11Small +dW R11Spread +dW SPDogSmall +dW E11DogSmall (6)

[0130] W E11Exit =W small -dW SPSmall -dW E11Small (7)

[0131] Among them, W R11Target The exit target width for the first pass of R1 in the small head section is based on this, and the exit target width for the first pass of R1 in the large head section is also based on this.

[0132] dW SPSmall This refers to the SP reduction amount for the smaller end portion in this pass. It is based on the width W of the smaller end portion of the incoming strip. Small The thickness reduction of the horizontal roll in each pass and the target width W of the strip at the roughing mill exit, calculated in step 1. Target By calling the width load distribution model, the SP reduction amount dW in the large-head portion can be obtained. SPBig E1 reduction for each forward pass (including the E1 reduction dW for the first pass) E11Small Reverse pass vertical roller empty), R11 exit width (i.e., target exit width W) R11Target ).

[0133] dW E11Small This refers to the E1 reduction amount in the first pass of the small-head portion E1.

[0134] dW R11Spread The horizontal width of the first pass of the small-head portion R1 is expanded.

[0135] dW SPDogSmall The dog bone of the small head portion SP is widened.

[0136] dW E11DogSmallThe dog bone is widened for the first pass of the E1 section of the small head.

[0137] W E11Exit E1 represents the exit width of the smaller end portion in the first pass (E1), i.e., the E1 roll gap value. For wedge-shaped billets, when calculating the SP reduction of the larger end portion, the E1 roll gap value is kept constant, and the SP is used for width adjustment. Therefore, the E1 roll gap value of the larger end portion remains unchanged in this pass.

[0138] The target exit width of the larger section in the first pass R1 is based on the target exit width of the smaller section in the first pass R1. Simultaneously, the E1 roll gap value of the larger section remains constant in this pass, causing the wedge-shaped strip to become an inverted wedge shape after being rolled by the variable roll gap of SP. Therefore, the SP reduction of the larger section is greater than that of the smaller section, while the E1 reduction of the larger section is less than that of the smaller section. Thus, the following formula holds:

[0139] W R11Target =W Big -dW SPBig -dW E11Big +dW R11Spread +dW SPDogBig +dW E11DogBig (8)

[0140] W E11Exit =W Small -dW SPSmall -dW E11Small ≤W Big -dW SPBig -dW E11Big (9)

[0141] Among them, dW SPBig This represents the SP reduction amount of the bulk portion in this pass.

[0142] dW E11Big This refers to the E1 reduction amount in the first pass of the E1 section.

[0143] dW SPDogBig The large part of the SP dog bone in this track is widened.

[0144] dW E11DogBig The dog bone of the first pass of E1 is widened for the large head section.

[0145] As can be seen from equation (9), with the small head as the benchmark, when adjusting the width using SP, the total SP reduction of the large head portion in that pass is fixed, the total E1 reduction of the large head portion in that pass is fixed, and at this time dW E11Big ≠0.

[0146] After the large end section undergoes SP side pressure, the exit width of the large end section is smaller than the roll gap value E1 of the original pass, causing dWE11Big The initial value is dW E11Small Decrease the length in increments of 2mm down to 0, using Newton's method of truncated chords, based on the entrance width W of the larger section. Big E1 reduction amount dW of the large end section E11Big The R1 reduction of the large end portion and the target exit width W of this pass. R11Target Calculate dW SPBig The iteration stops when one of the following conditions is met.

[0147] (III)dW E11Big ≠0 and inequality (10) holds.

[0148] |W Big -W E11Exit -dW SPBig -dW E11Big |≤2mm (10).

[0149] (IV)dW E11Big =0.

[0150] Step 8: Based on the SP reduction amount dW of the large head portion calculated in Step 7. SPBig SP reduction amount dW of the small end portion SPSmall Control the full-length variable roll gap rolling of strip steel.

[0151] In steps 6 and 8, during the SP full-length variable roll gap rolling process, for the head section of the wedge billet, the width before SP side pressing is the width of the billet head; for the tail section of the wedge billet, the width before SP side pressing is the width of the billet tail; and for the middle section of the trapezoidal wedge billet, the width before SP side pressing is calculated from the linear difference between the width of the billet head and the width of the billet tail.

[0152] The reduction amounts for each step of SP on the wedge blank are as follows: head reduction amount dW of the head section. SPHead Tail section tail compression amount dW SPTail And the middle section's reduction amount dW SPBody .

[0153] According to the rolling direction of the strip, if the smaller end is in front and the larger end is behind, then the head reduction dW SPHead SP reduction amount dW for the small end portion SPSmall Tail-end pressure dW SPTail SP reduction amount dW for the large head portion SPBig Conversely, if the larger end is in front and the smaller end is behind, then the head pressure amount dW SPHead SP reduction amount dW for the large head portion SPBig Tail-end pressure dW SPTail SP reduction amount dW for the small end portionSPSmall .

[0154] Middle reduction dW SPBody The calculation formula is:

[0155]

[0156] Among them, cL body This refers to the total length of the width adjustment section on the incoming strip steel.

[0157] sL is the cumulative length from the starting point of the strip width adjustment to the SP pressing position.

[0158] Step 9: Complete the rough rolling of this pass to obtain a rectangular strip.

[0159] For wedge-shaped billets, this invention fully utilizes the width adjustment capability of the strip (SP). During the rolling process, the roll gap value of the SP is continuously adjusted, so that the shape change process of the strip width is as shown in the attached figure. Figure 2 As shown, after passing through SP, the large end of the wedge-shaped billet becomes the small end, and the small end becomes the large end. Since the roll gap value of E1 is constant, the small end and the large end have the same exit width after E1 rolling. Finally, after passing through R1 rolling, a rectangular billet with the same head and tail width is obtained at the exit of the first pass of R1.

[0160] Example 1:

[0161] The parameters (in mm) of the strip steel (wedge-shaped billet) produced in this embodiment are as follows:

[0162] Cold resistance value of the head width of the incoming strip: 1605

[0163] Heat value of the strip head width: 1634.986

[0164] Cold resistance value of strip tail width: 1725

[0165] Heat value of the strip at the tail end of the incoming material: 1757.2279

[0166] Cold resistance value of incoming strip thickness: 241

[0167] Heat value of incoming steel strip thickness: 245.49521

[0168] Cooling value at the starting position of the wedge blank: 4388

[0169] Heat value at the starting position of the wedge-shaped billet: 4470.06

[0170] Cold value at the end position of the wedge blank: 8463

[0171] Heat value at the starting position of the wedge-shaped billet: 8621.26

[0172] Target width calorific value for rough rolling: 1623.4032

[0173] In this invention, calorific value parameters are used for model calculation.

[0174] Based on the large head size, the following calculations were performed:

[0175] The SP reduction of the large head section is dW SPBig =158.59145, the E1 reduction in the first pass is dW E11Big =30, W R11Target =1616.7223; W E11Exit =1568.63645.

[0176] Let dW E11Small =30, and increase the E1 reduction dW in the first pass of E1 in increments of 2mm. E11Small According to the width of the small end of the incoming strip, W R11Target Based on this information, the SP reduction dW of the small end portion is calculated using Newton's secant method. SPSmall After continuous iteration, when dW E11Small When = 50, dW SPSmall =0, meaning that the large head is the base, and there is no solution for the SP compression amount of the small head. At this time, it is converted to the small head as the base.

[0177] Based on the small head size, the following calculations were performed:

[0178] SP reduction amount dW at the small end SPSmall =17.393803, dW E11Small =30, W R11Target =1616.7223; W E11Exit =1587.592197.

[0179] Let dW E11Big =30, and decrease the reduction amount dW in 2mm increments. E11Big Until it reaches 0, based on the width of the larger end of the incoming strip, W R11Target Based on this information, the SP reduction dW of the larger section is calculated using Newton's secant method. SPBig After continuous iteration, when dW E11Big When dW = 0, SPBig The value is 175.28017.

[0180] The calculation results for the smaller head are as follows:

[0181] W Small =1634.986;

[0182] W SPSmall =17.393803;

[0183] dW E11Small =30;

[0184] dW E11ExitSmall =1587.592197;

[0185] dW R11Spread =8.6781588;

[0186] dW SPDogSmall =6.0321879;

[0187] dW E11DogSmall =14.419785;

[0188] W R11Target =1616.7223.

[0189] The calculation results for the larger portion are as follows:

[0190] W Big =1757.2279;

[0191] W SPBig =175.28017;

[0192] dW E11Big =0;

[0193] dW E11ExitBig =1,581.94773; less than dW E11DogSmall Since the roll gap value of E1 is constant in the first pass, the large part passes through the vertical roll E1 without passing through.

[0194] dW R11Spread =12.18618;

[0195] dW SPDogBig =22.58837;

[0196] dW E11DogBig =0;

[0197] W R11Target =1616.72228.

[0198] Based on the calculation results of the small end and the large end, the SP model calculates the roll gap value of SP using formula (11), as shown in Table 1.

[0199] Table 1 Output results of the wedge-shaped billet SP model

[0200]

[0201]

[0202] In this context, "wait" represents the pre-shooting position of the SP (Strip Plate). The SP needs to perform an action before shooting the incoming strip. The "position" corresponding to "wait" represents the distance between the head of the incoming strip and the SP position when the SP begins its pre-action. "headStep" represents the short stroke of the head, "head" represents the head pressing down, "body" represents the width adjustment section, and "tail" represents the tail pressing down. "tailStep" represents the short stroke of the tail, and "pressing down" is the pressing amount for that step. For example, with "point count 'wait,' step size '-1332,' position '-1332,' and pressing down '0'," the SP begins its pre-action when the slab head is 1332 units away from the SP position, and the pressing down amount for that step is 0. In the SP roll gap setting, the starting and ending positions of the wedge-shaped billet are slightly different from the given parameters for the incoming strip. This is because the SP model considers the strip extending along its length when the SP performs the pressing down action; this will not be elaborated further here.

[0203] The SP model controls the SP full-length variable roll gap rolling of strip steel according to Table 1. The exit width of the roughing mill in the first pass of R1 is shown in the attached figure. Figure 3 As shown, by appendix Figure 3 It can be seen that the strip width fluctuates little, and this embodiment has good control over the strip width.

[0204] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the width of a wedge-shaped strip steel based on a large side press device, the method being applied to a hot rolling production line, the hot rolling production line being provided with a large side press device (SP), a first vertical roll (E1), a first horizontal roll (R1), a second vertical roll (E2), and a second horizontal roll (R2) ; the method comprising the following steps: Step 2: judging whether the strip steel is a wedge-shaped blank, if not, executing Step 3, if yes, executing Step 4; Step 3: according to the width of the strip steel, calling a width load distribution model, the SP calculating the side press reduction according to the width load distribution model, and controlling the width of the strip steel in the pass with a constant roll gap, and turning to Step 9; Step 4: taking the large head part as a reference, calling the width load distribution model, keeping the target width of the strip steel at the exit of the pass, and keeping the roll gap of the E1 unchanged in the pass, and calculating the SP reduction of the large head part and the SP reduction of the small head part; Step 5: the SP model judging whether the width adjustment condition based on the small head part is met according to the SP reduction of the large head part and the SP reduction of the small head part calculated in Step 4, if not, executing Step 6, if yes, executing Step 7; Step 6: the SP model controlling the SP to roll the strip steel with a variable roll gap according to the SP reduction of the large head part and the SP reduction of the small head part calculated in Step 4, and turning to Step 9; Step 7: taking the small head part as a reference, calling the width load distribution model, keeping the target width of the strip steel at the exit of the pass, keeping the roll gap of the E1 unchanged in the pass, and calculating the SP reduction of the small head part and the SP reduction of the large head part; Step 8: controlling the SP to roll the strip steel with a variable roll gap according to the SP reduction of the large head part and the SP reduction of the small head part calculated in Step 7; Step 9: completing the rough rolling in the pass, and obtaining a rectangular strip steel; the width adjustment condition based on the small head part in Step 5 comprises: when the condition (I) or (II) is met, the width adjustment based on the large head part has no solution, and the width adjustment based on the small head part is converted, i.e., Step 7 is executed; the calculation method of the SP reduction of the small head part in Step 4 is: the strip steel with a wedge-shaped part passes through the SP, the E1 and the R1 in sequence, and the following formula is established: from formula (4), when the width adjustment based on the large head part is performed by the SP, the total SP reduction of the small head part in the pass is fixed, and the total E1 reduction of the small head part in the pass is fixed; the calculation method of the SP reduction of the small head part in Step 7 is: the strip steel with a wedge-shaped part passes through the SP, the E1 and the R1 in sequence, and the following formula is established: the target width of the large head part at the exit of the first pass of the R1 is based on the target width of the small head part at the exit of the first pass of the R1, and the roll gap value of the E1 of the large head part in the pass is kept unchanged, and the following formula is established: The application is characterized in that ​ Step 1: Calculate the horizontal roll thickness load distribution to determine the target width W of the strip at the exit of the roughing pass Target ; ​ ​ ​ ​ ​ ​ ​ ​ ​ (I) the small head part is skipped in the pass SP; when dW SPSmall = 0, the small head part is skipped in the pass SP; (II) E1 first pass load full; when dW E11Small =E1 first pass maximum reduction, E1 first pass load full; wherein dW SPSmall is the reduction of the small end portion in the pass SP. dW E11Small E1 is the first pass reduction for the small end portion E1; ​ 2. The wedge-shaped strip steel width control method based on a large side pressure apparatus according to claim 1, characterized by: ​ ​ （1） （2） wherein W R11Target is the exit target width of the large head portion R1 first pass, the exit target width of the small head portion in the R1 first pass is also subject to this. dW SPBig SP reduction of the large end portion in the pass; dW E11Big E1 is the first pass reduction for the large end portion; dW R11Spread horizontal spread for the first pass of the large end portion R1; dW SPDogBig is the dog bone width of the large head portion SP; dW E11DogBig dog bone width spread for first pass of large end portion E1; W E11Exit E1 is the exit width of the first pass for the large head portion E1, i.e. the E1 roll gap value when the width is adjusted based on the large head portion. The exit target width of the small head portion R1 first pass is equal to the exit target width of the large head portion R1 first pass, i.e. W R11Target For reference, at the same time, the E1 roll gap value of the small head portion in the E1 first pass remains unchanged, and the following formula is established: （3） （4） wherein dW SPSmall is the reduction of the small end portion in the pass SP. dW E11Small E1 is the first pass reduction for the small end portion E1; dW R11Spread horizontal spread for the first pass of the small end portion R1; dW SPDogSmall is the SP dog bone width of the small head portion in the pass; dW E11DogSmall dog bone width spread for the first pass of the small end portion E1; ​ Let dW E11Small be the initial value of dW E11Big , increase it by 2mm step by step, and use Newton chord intercept method to calculate dW Small according to the inlet width W E11Small of the small head part, the E1 reduction dW R11Target of the first pass of the small head part E1, the R1 reduction of the first pass of the small head part R1, and the target outlet width W SPSmall of the pass, and stop iteration when inequality (5) is established. （5）。 3. The method of claim 2, wherein: The horizontal spread model is: ; where h0 is the entry thickness of R1, hi is the strip exit thickness of R1, T is the entry temperature of R1, W e is the exit width after rolling of E1, i.e., the entry width of R1.

4. The method of claim 3, wherein: The E1 exit width W after rolling e The model is: ; wherein W0 is the width of the strip steel incoming material, dW SP is the SP reduction, dW Edger is the E1 reduction.

5. The method of claim 2, wherein: the wedge-shaped strip steel width control method based on the large lateral pressure equipment is characterized by: The model of the dog bone width expansion of the SP is: .

6. The method of claim 2, wherein: The dog bone width expansion model of E1 is dW EdgerDog = f(W1,W e ,h0,R), wherein W1 is the strip width before the E1 side press, W1 = W0 - dW SP , and R is the radius of R1.

7. The method of claim 1, wherein: ​ ​ （6） （7） wherein W R11Target is the exit target width of the first pass for the small end portion R1, and the exit target width of the first pass for the large end portion is also based on this value; dW SPSmall SP reduction of the small end portion in the pass; dW E11Small E1 is the first pass reduction for the small end portion E1; dW R11Spread horizontal spread for the first pass of the small end portion R1; dW SPDogSmall is the dog bone width of the small head portion SP; dW E11DogSmall dog bone width spread for the first pass of the small end portion E1; W E11Exit Wout is the exit width of the small end portion at the first pass E1, i.e. the roll gap value of E1; ​ （8） （9） wherein dW SPBig is the SP reduction of the large end portion in the pass; dW E11Big E1 is the first pass reduction for the large end portion E1; dW SPDogBig is the SP dog bone width of the large head portion at the pass; dW E11DogBig dog bone width for the first pass of the large end portion E1; As can be seen from equation (9), with the small head as the benchmark, when adjusting the width using SP, the total SP reduction of the large head portion in that pass is fixed, the total E1 reduction of the large head portion in that pass is fixed, and at this time dW E11Big ≠0; Let dW E11Big be the initial value of dW E11Small , and reduce it to 0 with a step of 2 mm, using the Newton chord intersection method, according to the inlet width W Big of the large-head part, the E1 reduction dW E11Big of the large-head part, the R1 reduction of the large-head part, and the target outlet width W R11Target of the pass, to calculate dW SPBig , and stop the iteration when one of the following conditions is met: (III) dW E11Big ≠ 0 and inequality (10) holds: （10）； (IV) dW E11Big = 0.

8. The method of claim 1, wherein the wedge-shaped strip steel width control based on the high lateral pressure equipment is characterized by In the step 6 and step 8, in the process of the full-length SP wedge rolling, the width of the SP before side pressing for the head section of the wedge blank is the width of the slab head, the width of the SP before side pressing for the tail section of the wedge blank is the width of the slab tail, and the width of the SP before side pressing for the middle section of the wedge blank is calculated by the linear difference between the width of the slab head and the width of the slab tail. The SP has a head reduction amount dW SPHead , a tail reduction amount dW SPTail , and a middle reduction amount dW SPBody for each step of the wedge-shaped blank, respectively. The middle reduction dW SPBody The calculation formula is: （11） wherein cL body is the total length of the portion of the strip to be widened; sL is the cumulative length from the starting point of the strip width adjustment to the SP position.

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