CN102125934A - Single-stand rough rolling width-reduction control method - Google Patents

Abstract

The invention discloses a single-stand rough rolling width-reduction control method. The maximum reduction of a vertical roll in each pass is calculated according to a formula, and a width reduction correction factor lambda is introduced in the calculation to correct the reduction of the vertical roll, so that the width of an intermediate blank after rough rolling reaches the outlet width; meanwhile, a finishing mill adopts a large-tension rolling method, and different tension is set according to different steel types, so that the broadening is avoided in the finishing, and the aim that the effective width reduction is 40mm is fulfilled.

Description

The single chassis roughing subtracts width controlling method

Technical field

The present invention relates to the finished width control method used in a kind of strip hot rolling process, particularly the single chassis roughing subtracts width controlling method.

Background technology

The means that do not have width control in strip hot rolling process owing to finish rolling, finished width control is mainly finished in the roughing zone, therefore must calculate the width of the middle blank of roughing outlet according to the target width of finished strip.In the middle of determining, will consider in the finish rolling operation of rolling influence in the process of blank to product width.Subtracting of slab widely mainly carried out in roughing.The wide technology that subtracts of utilization at present mainly contains Fixed width forcing press and big edger roll, to arrive the wide purpose that subtracts of slab, to realize free rolling.In the domestic hot continuous rolling unit, be configured to the little edger roll roughing mill of single chassis, all adopt wide rolling mill practice mode, realizing subtracting wide rolling, can't subtract wide rollingly owing to be subjected to the restriction of rolling pass temperature drop and rolling rhythm.Make that free rolling technology is limited, the slab specification is many, has increased the cost of continuous casting billet.

1750 hot rolling units for some steel plant's use of China, what dispose is the little edger roll roughing of single chassis unit, be wide rolling in the design, owing to have only a roughing mill, and be little edger roll, can't subtract wide rollingly, cause the continuous casting billet width specifications more, rolling scaduled layout difficulty has increased the continuous casting cost.

Summary of the invention

The object of the present invention is to provide a kind of single chassis roughing to subtract width controlling method, under the appointed condition of the little edger roll of single chassis, can reach the target that finished width subtracts wide 40mm, reduce the continuous casting billet specification, reduce cost, improve the ability of free rolling.

The object of the present invention is achieved like this: a kind of single chassis roughing subtracts width controlling method, and this method at first need not produce under the condition of unstability distortion at equipment, derives maximum reduction by following formula:

$d_e=\min [\frac{w_0\×\mathrm{\λ}\×f(w_0/h_0)}{100},d_{e,\max },d_{e,F_{\max }}]$

In the formula: w ₀-throat width; h ₀-inlet thickness; d _{E, max}The width maximum reduction; De-width drafts; F (w ₀/ h ₀)-edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation; d _{E, Fmax}Drafts when-roll-force is maximum;

About determining of edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation:

If m=w ₀/ h ₀,

When m＜10, x=10 is arranged,

p _x＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

d(p _x)＝a ₁+x×(2.0×a ₂+x×(3.0×a ₃+x×4.0×a ₄))；

f(m)＝p _x+dp _x×(m-x)；

When 10≤m＜40, x=m is arranged,

f(m)＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

When m 〉=40, x=40 is arranged,

f(m)＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

The assigning process of each reduction in pass of the relevant calculation edger roll operation of rolling is as follows:

(1) at first calculate every time required Breadth Maximum drafts according to target width, and the drafts of maximum rolling force;

(2) drafts of depressing modifying factor λ opposite roller according to a width of calculate introducing is then revised, and calculates the maximum reduction that does not produce under the unstability distortion.Suitable through actual measurement and calculating λ value 0.4～0.45;

(3) get the minimum of a value of three values after calculating finishes;

Subtracting widely when rolling, independent model strategy is used in finish rolling, and mm finishing mill unit adopts spreading of the rolling inhibition finish rolling of hightension, reaches that finish rolling is not spreaded or negative spreading;

Subtract that finish rolling tension force setting value is when wide: L1:12-15N/mm ²L2:12-17N/mm ²L3:13-18N/mm ²L4:14-19N/mm ²L5:15-19N/mm ²

Reach the control of width by the self study of width model:

About self study coefficient corLat is spreaded in roughing, corBul, corWid divide steel grade and width to consider; Steel grade in same and width are considered stage by stage again preceding two passages of general roughing are a stage, latter two passage is a stage, and pony-roughing pass is a stage, when even-numbered pass roughing is spreaded and carries out self study;

1) the short-term self study is spreaded in roughing

Calculate new width control parameter

Calculate the thick mouthful width of roughing relatively and the sensitivity coefficient of width control coefrficient

$S_{W_x}=\frac{{\∂W}_2}{\∂{\mathrm{cor}}_x}=\frac{{\mathrm{\ΔW}}_2}{\mathrm{\Δ}{\mathrm{cor}}_x}=\frac{W_2\left({\left({\mathrm{cor}}_2\right)}_2\right)-W_2\left({\left({\mathrm{cor}}_x\right)}_1\right)}{{\left({\mathrm{cor}}_x\right)}_2-{\left({\mathrm{cor}}_x\right)}_1}$

2) long-term self study is spreaded in roughing

${\left({\mathrm{cor}}_x\right)}_{\mathrm{new}}={\left({\mathrm{cor}}_x\right)}_{\mathrm{old}}+\frac{r*S_{W_x}*\mathrm{\δ}{W}_x}{s_{\mathrm{new}}}$

(cor _x) _New: spread coefficient after the long-term self study

(cor _x) _Old: spread the preceding coefficient of long-term self study

Self study is spreaded in 2 finish rolling

Self study coefficient Nai Wadp is spreaded in relevant finish rolling, and classifying according to the effective cold width of steel grade and finish rolling outlet band steel is saved in the database table;

1) finish rolling width short-term self study

According to the measurement of the finishing mill exit width of measuring and the measured value of middle blank, calculate the thick mouthful width value of finish rolling

${\left(\mathrm{\Δ}{W}_{\mathrm{adp}}\right)}_{\mathrm{cur}}={\mathrm{\ΔW}}_{\mathrm{adp}}+(\stackrel{\‾}{W_{\mathrm{mea}}}-W_{\mathrm{cal}})$

2) the long-term self study of finish rolling width

(ΔW _adp) _new＝(ΔW _adp) _old+r*((ΔW _adp) _cur-(ΔW _adp) _old)

The inventive method can reach the target that finished width subtracts wide 40mm under the appointed condition of the little edger roll of single chassis, reduce the continuous casting billet specification, reduces cost, and improves the ability of free rolling.

The specific embodiment (should enumerate an example that in actual production, specifically used) by the concrete computational process of substitution numeral explanation

A kind of single chassis roughing subtracts width controlling method, and this method at first need not produce under the condition of unstability distortion at equipment, derives maximum reduction by following formula:

$d_e=\min [\frac{w_0\×\mathrm{\λ}\×f(w_0/h_0)}{100},d_{e,\max },d_{e,F_{\max }}]$

In the formula: w ₀-throat width; h ₀-inlet thickness; d _{E, max}The width maximum reduction; De-width drafts; F (w ₀/ h ₀)-edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation; d _{E, Fmax}Drafts when-roll-force is maximum;

About determining of edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation:

If m=w ₀/ h ₀,

When m＜10, x=10 is arranged,

p _x＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

d(p _x)＝a ₁+x×(2.0×a ₂+x×(3.0×a ₃+x×4.0×a ₄))；

f(m)＝p _x+dp _x×(m-x)；

When 10≤m＜40, x=m is arranged,

f(m)＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

When m 〉=40, x=40 is arranged,

f(m)＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

The assigning process of each reduction in pass of the relevant calculation edger roll operation of rolling is as follows:

(1) at first calculate every time required Breadth Maximum drafts according to target width, and the drafts of maximum rolling force;

(2) drafts of depressing modifying factor λ opposite roller according to a width of calculate introducing is then revised, and calculates the maximum reduction that does not produce under the unstability distortion.Suitable through actual measurement and calculating λ value 0.4～0.45;

(3) get the minimum of a value of three values after calculating finishes;

Subtracting widely when rolling, independent model strategy is used in finish rolling, and mm finishing mill unit adopts spreading of the rolling inhibition finish rolling of hightension, reaches that finish rolling is not spreaded or negative spreading;

Subtract that finish rolling tension force setting value is when wide: L1:12-15N/mm ²L2:12-17N/mm ²L3:13-18N/mm ²L4:14-19N/mm ²L5:15-19N/mm ²

Reach the control of width by the self study of width model:

About self study coefficient corLat is spreaded in roughing, corBul, corWid divide steel grade and width to consider; Steel grade in same and width are considered stage by stage again preceding two passages of general roughing are a stage, latter two passage is a stage, and pony-roughing pass is a stage, when even-numbered pass roughing is spreaded and carries out self study;

1) the short-term self study is spreaded in roughing

Calculate new width control parameter

Calculate the thick mouthful width of roughing relatively and the sensitivity coefficient of width control coefrficient

$S_{W_x}=\frac{{\∂W}_2}{\∂{\mathrm{cor}}_2}=\frac{{\mathrm{\ΔW}}_2}{\mathrm{\Δ}{\mathrm{cor}}_2}=\frac{W_2\left({\left({\mathrm{cor}}_x\right)}_2\right)-W_2\left({\left({\mathrm{cor}}_x\right)}_1\right)}{{\left({\mathrm{cor}}_x\right)}_2-{\left({\mathrm{cor}}_x\right)}_1}$

2) long-term self study is spreaded in roughing

${\left({\mathrm{cor}}_x\right)}_{\mathrm{new}}={\left({\mathrm{cor}}_x\right)}_{\mathrm{old}}+\frac{r*S_{W_x}*\mathrm{\δ}{W}_x}{s_{\mathrm{new}}}$

(cor _x) _New: spread coefficient after the long-term self study

(cor _x) _Old: spread the preceding coefficient of long-term self study

Self study is spreaded in 2 finish rolling

Self study coefficient Nai Wadp is spreaded in relevant finish rolling, and classifying according to the effective cold width of steel grade and finish rolling outlet band steel is saved in the database table;

1) finish rolling width short-term self study

According to the measurement of the finishing mill exit width of measuring and the measured value of middle blank, calculate the thick mouthful width value of finish rolling

${\left({\mathrm{\ΔW}}_{\mathrm{adp}}\right)}_{\mathrm{cur}}={\mathrm{\ΔW}}_{\mathrm{adp}}+(\stackrel{\‾}{W_{\max }}-W_{\mathrm{cal}})$

2) the long-term self study of finish rolling width

(ΔW _adp) _new＝(ΔW _adp) _old+r*((ΔW _adp) _cur-(ΔW _adp) _old)

Claims (1)

1. a single chassis roughing subtracts width controlling method, it is characterized in that: this method at first need not produce under the condition of unstability distortion at equipment, derives maximum reduction by following formula:

$d_e=\min [\frac{w_0\×\mathrm{\λ}\×f(w_0/h_0)}{100},d_{e,\max },d_{e,F_{\max }}]$

In the formula: w ₀-throat width; h ₀-inlet thickness; d _{E, max}The width maximum reduction; De-width drafts; F (w ₀/ h ₀)-edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation; d _{E, Fmax}Drafts when-roll-force is maximum;

(1), determining about edger roll width maximum reduction and rolled piece flakiness ratio coefficient correlation:

If m=w ₀/ h ₀, when m＜10, x=10 is arranged,

p _x＝a ₀+x×(a ₁+x×(a ₃+x×a ₄)))；

d(p _x)＝a ₁+x×(2.0×a ₂+x×(3.0×a ₃+x×4.0×a ₄))；

f(m)＝p _x+dp _x×(m-x)；

When 10≤m＜40, x=m is arranged, f (m)=a ₀+ x * (a ₁+ x * (a ₃+ x * a ₄)));

When m 〉=40, x=40 is arranged, f (m)=a ₀+ x * (a ₁+ x * (a ₃+ x * a ₄)));

(2), the assigning process of each reduction in pass of the relevant calculation edger roll operation of rolling is as follows:

A, at first calculate every time the required Breadth Maximum drafts and the drafts of maximum rolling force according to target width;

B, a width of introducing according to calculating are then depressed the drafts of modifying factor λ opposite roller and revised, and calculate the maximum reduction that does not produce under the unstability distortion, and be suitable 0.4～0.45 through actual measurement and calculating λ value;

After finishing, C, calculating gets the minimum of a value of three values;

(3), subtracting widely when rolling, independent model strategy is used in finish rolling, mm finishing mill unit adopts spreading of the rolling inhibition finish rolling of hightension, reaches that finish rolling is not spreaded or negative spreading;

(4), subtract that finish rolling tension force setting value is when wide: L1:12-15N/mm ²L2:12-17N/mm ²L3:13-18N/mm ²L4:14-19N/mm ²L5:115-19N/mm ²

(5), reach the control of width by the self study of width model:

About self study coefficient corLat is spreaded in roughing, corBul, corWid divide steel grade and width to consider; Steel grade in same and width are considered stage by stage again preceding two passages of general roughing are a stage, latter two passage is a stage, and pony-roughing pass is a stage, when even-numbered pass roughing is spreaded and carries out self study;

1) the short-term self study is spreaded in roughing, calculates new width control parameter, calculates the thick mouthful width of roughing relatively and the sensitivity coefficient of width control coefrficient:

$S_{W_x}=\frac{{\∂W}_2}{\∂{\mathrm{cor}}_x}=\frac{{\mathrm{\ΔW}}_2}{\mathrm{\Δ}{\mathrm{cor}}_x}=\frac{W_2\left({\left({\mathrm{cor}}_x\right)}_2\right)-W_2\left({\left({\mathrm{cor}}_x\right)}_1\right)}{{\left({\mathrm{cor}}_x\right)}_2-{\left({\mathrm{cor}}_x\right)}_1}$

2) long-term self study is spreaded in roughing:

${\left({\mathrm{cor}}_x\right)}_{\mathrm{new}}={\left({\mathrm{cor}}_x\right)}_{\mathrm{old}}+\frac{r*S_{W_x}*{\mathrm{\δW}}_x}{s_{\mathrm{new}}}$

(cor _x) _New: spread coefficient after the long-term self study

(cor _x) _Old: spread the preceding coefficient of long-term self study

Self study is spreaded in finish rolling, and self study coefficient Wadp is spreaded in relevant finish rolling, and classifying according to the effective cold width of steel grade and finish rolling outlet band steel is saved in the database table;

3) finish rolling width short-term self study:

According to the measurement of the finishing mill exit width of measuring and the measured value of middle blank, calculate the thick mouthful width value of finish rolling:

4) the long-term self study of finish rolling width:

(ΔW _adp) _new＝(ΔW _adp) _old+r*((ΔW _adp) _cur-(ΔW _adp) _old)