CN110102579A - Low-cost control method for eliminating width of slab wedge - Google Patents

Abstract

The invention relates to a low-cost width control method for eliminating slab wedges. During the rolling process of the first rough rolling pass from the beginning to the end, the actual width of the head and tail of the strip is recorded, and the width difference between the head and the tail is calculated. ; In the edge rolling process from the beginning to the end of the third rolling pass, according to the width difference between the head and the tail, the width of the rough rolling exit is dynamically adjusted through the dynamic setting of the vertical roller gap. The invention has the advantages that it is suitable for the production line of medium and thin slabs which has no entrance width gauge and cannot realize width feed-forward control. The rough rolling adopts 3-pass rolling, which can eliminate the wedge shape of the slab less than 20mm.

Description

A Low Cost Width Control Method for Slab Wedging Elimination

technical field

The invention belongs to the technical field of rough rolling of hot-rolled strips, and in particular relates to a low-cost method for controlling the width of a slab wedge, which is suitable for a hot-rolling unit with only one rough-rolling vertical roller mill.

Background technique

Compared with the conventional slab hot rolling production line, the single vertical roller mill production line (the hot rolling roughing mill has only one vertical roller mill) has less investment and less equipment. Generally, only one width gauge is arranged for rough rolling. Limited by one vertical rolling mill and one width gauge, there are only two automatic width control functions—short-stroke AWC and rolling force AWC, and the ability to guarantee width control is relatively weak.

The comparison of width control equipment and width measuring instruments between a typical single vertical roll mill production line and a conventional slab hot continuous rolling production line is as follows:

Since the rolling process width control equipment of the single vertical roller mill production line is only E1 (vertical roller mill), the maximum side pressure of the rolling mill is 50mm, and the width feedforward control cannot be realized when there is no width gauge in front of the equipment. When the billet width appears wedge-shaped (even if it conforms to the national standard YB/T 2012-2004 for continuous casting slab width wedge-shaped standard, the actual head-to-tail width difference is between 0 and 20mm), the rolling process width control accuracy index will decrease, and in serious cases, it will appear Partial ultra-wide or narrow ruler, resulting in unqualified products.

The national standard YB/T 2012-2004 stipulates the continuous casting slab width wedge shape standard: the width difference at 150mm from the beginning and end of the slab│WW ₂ │≤20mm.

The current state of the art at home and abroad: the width control of hot-rolled strip steel is due to the different equipment and equipment of each production line, and the control function increases or decreases with the equipment and equipment. Generally equipped hydraulic vertical roll mill production line has AWC function, rough rolling has four AWC functions of short stroke AWC, rolling force AWC, feedforward AWC, and dynamic setting. Among them, the feed-forward AWC function can solve the problem of wedge width of the slab. The feed-forward AWC and dynamic setting functions of the AWC function need to be equipped with a width gauge in front of the vertical roll mill, and control is performed according to the actual measurement of the slab width data by the width gauge. If the vertical roll mill is not equipped with a width measuring instrument, and there is no other width control equipment, the wedge width of the billet is uncontrollable.

Contents of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a low-cost width control method for eliminating the wedge shape of the slab. Without a width measuring instrument before the vertical roll mill and without other width control equipment, the method can be used at a minimum Eliminate the slab wedge and solve the problem of poor finished strip width caused by the slab width wedge.

To achieve the above object, the present invention is achieved through the following technical solutions:

A low-cost width control method for eliminating slab wedges. During the rolling process of the first rough rolling pass from the beginning to the end, the actual width of the head and tail of the strip is recorded, and the width difference between the head and the tail is calculated; During the edge rolling process of the three rolling passes from the beginning to the end, according to the width difference between the head and the tail, through the dynamic setting of the vertical roller gap, the width of the rough rolling exit is dynamically adjusted, which specifically includes the following steps:

1) Start to run the second-level model receiving data processing program at the end of the transition between the first pass and the second pass and the end of the third pass width measurement. start operation;

① In order to eliminate the erroneous data in the actual feedback value of the width deviation transmitted from the first stage, the actual value of the width deviation of the first pass is smoothed:

In formula (1): ⊿RDW(i) is the actual value of the saved width deviation of the first pass;

TSN is the total number of sampling points, which is determined by the actual sampling number of the width gauge;

②The unit width wedge value of the first pass of the current volume:

In formula (2), CTPCR1 is the unit width wedge value of the first pass of the current volume;

NSN is the number of sampling points in the unstable area of the head, ranging from 16 to 45, and must cover the unstable area;

③Unit width wedge control parameters, directly acting on the third vertical roller gap:

TPCR＝G1×CTPCR1+(1-FTTPCR)×LTPCR3 (3)

In the formula (3), TPCR is the unit width wedge control parameter of the current roll, the unit is mm, and it directly acts on each aperture scanning period of the third vertical roller;

G1 is the current adjustment gain of the unit width wedge control parameter, ranging from 0.5 to 1.5;

FTPCR is the unit width wedge control parameter learning adjustment gain, the range is 0~1;

LTPCR3 is the actual unit width wedge value of the third pass of the last steel coil, the calculation method is the same as formula (2), and the initial value is 0; the data processing method is the same as formula (1);

④ Judgment of credibility of unit width wedge control parameters:

If TPCR<Lmt2 or TPCR>Lmt 1 update the unit width wedge control parameter TPCR, otherwise the current TPCR value is invalid, the unit width wedge control parameter TPCR will not be updated, and the TPCR of the previous roll is still used;

Lmt 1 is the lower limit of the deviation of the wedge-shaped control parameter per unit width;

Lmt2 is the upper limit of the deviation of the unit width wedge control parameter.

After the short-stroke AWC at the head of the vertical roll in the third rolling pass, the first-level control system starts to execute the wedge-shaped control parameters per unit width. The adjustment of the opening of the vertical roll in each scanning cycle is TPCR, and it stops when the short-stroke AWC at the tail is executed; Do not input the rolling force AWC function during execution;

When the first pass and the second pass are switched, the second-level model receiving data processing program is started to take into account production efficiency and as much data volume as possible.

Compared with prior art, the beneficial effect of the present invention is:

The invention is suitable for the production line of medium and thin slabs which has no entrance width gauge and cannot realize width feed-forward control in rough rolling. The rough rolling adopts 3-pass rolling, which can eliminate the wedge shape of the slab less than 20mm. Due to the pre-control of the slab width wedge, it plays the role of width feedforward control to a certain extent, saving the investment of width measuring instruments. This function has been stably put into use in the 1700ASP production line of Jinan Iron and Steel Co., Ltd. for 10 years to eliminate the wedge shape of the slab less than 20mm, and the effect has been consistent. very good.

Description of drawings

Figure 1 is a definition map of the unstable region and the stable region.

Figure 2 is a control flow diagram.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings, but it should be pointed out that the implementation of the present invention is not limited to the following embodiments.

The low-cost width control method for eliminating the slab wedge is suitable for the medium slab (thickness 135-170mm) production line for rough rolling without an entrance width gauge and cannot realize width feed-forward control. It is used for rough rolling for 3 passes, and can Eliminate the wedge shape of the slab less than 20mm; during the rolling process of the first rough rolling pass from the beginning to the end, record the actual width of the head and tail of the strip, and calculate the width difference (wedge) between the head and the tail. During the edge rolling process of the third rolling pass from the beginning to the end, according to the size of the wedge, through the dynamic setting of the vertical roll gap, the rough rolling exit width is dynamically adjusted; when the rough rolling setting calculation is normal, the AWC sampling Operate when the data is normal, the actual result data is provided by the first-level computer, and the setting data of the roughing mill is input to this function from other functions. The specific process is shown in Figure 2.

A low-cost method for controlling the width of a slab wedge, which specifically includes the following steps:

1) Start to run the second-level model receiving data processing program at the end of the transition between the first pass and the second pass and the end of the third pass width measurement. start operation.

① In order to eliminate the erroneous data in the actual feedback value of the width deviation transmitted from the first stage, the actual value of the width deviation of the first pass is smoothed:

In formula (1): ⊿RDW(i) is the actual value of the saved width deviation of the first pass;

TSN is the total number of sampling points, which is determined by the actual number of samples taken by the width gauge.

②The unit width wedge value of the first pass of the current volume:

In formula (2), CTPCR1 is the unit width wedge value of the first pass of the current volume;

NSN is the number of sampling points in the unstable area of the head (determined manually based on the actual shape of the rolled piece, ranging from 16 to 45, and must cover the unstable area).

③Unit width wedge control parameters, directly acting on the third vertical roller gap:

TPCR＝G1×CTPCR1+(1-FTTPCR)×LTPCR3 (3)

In the formula (3), TPCR is the unit width wedge control parameter of the current roll, the unit is mm, and it directly acts on each aperture scanning period of the third vertical roller;

G1 is the current adjustment gain of the unit width wedge control parameter, which is given by manual experience according to the actual width control results, and the range is 0.5 to 1.5;

FTPCR is the unit width wedge control parameter learning adjustment gain, which is given by manual experience according to the actual width control results, and the range is 0~1;

LTPCR3 is the actual unit width wedge value of the third pass of the last steel coil, the calculation method is the same as formula (2), the initial value is 0, and the data processing method is the same as formula (1).

④ Judgment of credibility of unit width wedge control parameters:

If TPCR<Lmt2 or TPCR>Lmt 1 update the unit width wedge control parameter TPCR, otherwise the current TPCR value is invalid, the unit width wedge control parameter TPCR will not be updated, and the TPCR of the previous roll is still used;

Lmt 1 is the lower limit of the deviation of the wedge-shaped control parameter per unit width;

Lmt2 is the upper limit of the deviation of the unit width wedge control parameter.

2) After the execution of the short-stroke AWC at the head of the vertical roll in the third rolling pass, the first-level control system starts to execute the wedge-shaped control parameters per unit width. stop. The rolling force AWC function cannot be put into operation when the control method of the present invention is executed.

When the first pass and the second pass are switched, the model receiving data processing program is started to take into account the production efficiency and the amount of data as much as possible.

The method of the present invention is applied in the 1700ASP production line of Jinan Iron and Steel Co., Ltd. Before this function is put into use, the wedge shape of the head and tail width of the finished product is greater than 5mm on average about 4 coils per rolling cycle. It played an important role in the smooth passing of the index during the acceptance assessment of the guaranteed value of the width index of the 1700ASP production line of Jinan Iron and Steel Co., Ltd. The 1700ASP production line of Jinan Iron and Steel Co., Ltd. has been stably put into use for 10 years, and the effect has been very good to eliminate the wedge shape of the slab less than 20mm. The rough rolling adopts 3-pass rolling. Because the wedge shape of the slab width is controlled in advance, the width feedforward is played to a certain extent. control effect. The invention plays the role of replacing hardware with software to a certain extent, saves the investment of width measuring instruments, and has great popularization value in the design process of ordinary hot rolling production lines for today's advocating low-carbon economy.

Claims (2)

1. it is a kind of low cost eliminate slab wedge shape width control method, which is characterized in that the first rolling pass of roughing from the beginning Into the operation of rolling of tail overall length, record paper steel toe tail developed width, and it is poor to calculate head and tail width；Third rolling pass from the beginning It is poor according to head and tail width into the edge operation of rolling of tail overall length, it is set by the dynamic of edger roll roll gap, dynamic adjusts roughing and goes out Mouth width degree, specifically includes the following steps:

1) second-level model that brings into operation at the end of the first passage and the conversion of the second passage and third passage width measurement receives number According to processing routine, second level setup algorithm program brings into operation when roughing the second passage plain-barreled roll stings steel；

1. in order to eliminate the wrong data in the width difference actual feedback that level-one transmitting comes up, to the first passage width difference Actual value is smoothed:

In formula (1): ⊿ RDW (i) is the actual value of the first passage width difference saved；

TSN is total sampling number, is determined by width gage actual samples number；

2. currently rolling up the unit width shim values of the first passage:

In formula (2), CTPCR1 is the unit width shim values of the first passage of current volume；

NSN is head unstable region number of sampling points, range 16~45, it is necessary to cover unstable region；

3. unit width wedge shape control parameter directly acts on third passage edger roll roll gap:

TPCR=G1 × CTPCR1+ (1-FTPCR) × LTPCR3 (3)

In formula (3), TPCR is the unit width wedge shape control parameter currently rolled up, and unit mm is applied directly to third passage edger roll Each opening degree scan period；

G1 is that unit width wedge shape control parameter currently adjusts gain, range 0.5~1.5；

FTPCR is unit width wedge shape control parameter learning regulation gain, range 0~1；

LTPCR3 is the effective unit width shim values of upper coil third passage, the same formula of calculation method (2), initial value 0；Number According to the same formula of processing method (1)；

4. unit width wedge shape control parameter Credibility judgement:

If TPCR < Lmt2 or TPCR > Lmt 1 update unit width wedge shape control parameter TPCR, otherwise current TPCR value without Effect, unit width wedge shape control parameter TPCR do not update, and still use the TPCR of upper a roll；

Lmt 1 is the lower limit of unit width wedge shape control parameters error；

Lmt2 is the upper limit of unit width wedge shape control parameters error.

2. the width control method that a kind of low cost according to claim 1 eliminates slab wedge shape, which is characterized in that the First class control system starts executable unit's width wedge shape control parameter after three rolling pass edger roll head short stroke AWC are executed, Each scan period edger roll opening adjustment amount is TPCR, is stopped when tail portion short stroke AWC is executed；Rolling is not put into when execution Power AWC function；

Starting second-level model receives data processor when first passage and the second passage are converted, to take into account production efficiency and to the greatest extent may be used Data volume more than energy.