CN101134207A - Processing method of the hot rolling arrived material convexity in the computing of cold rolled sheet shape initialization - Google Patents

Abstract

The present invention relates to shape control method for cold rolled steel strip, and discloses method of treating convexity degree of the hot rolled material in the cold rolled steel strip shape setting and calculating. The treating method includes compensating calculation based on the sectional convexity degree data from hot rolling to eliminate the error caused by post step, and calculating the current convexity degree as the input condition for the accurate pre-calculation and post-calculation of roller bending force based on the current steel strip rolling position. The present invention can realize accurate setting in the whole length of steel strip without need of complicated and costly convexity degree measuring instrument in front of the cold rolling mill, and has saving in investment and lowered cost.

Description

The processing method of incoming hot rolled slab convexity during cold rolled sheet shape initialization calculates

(1) technical field

The present invention relates to the board-shape control method of cold-strip steel, relate in particular to the processing method of incoming hot rolled slab convexity in the cold rolled sheet shape initialization calculating.

(2) background technology

During hot rolling, for making band steel stable smooth operation, band steel cross section keeps certain convexity always.The hot rolling convexity that the hot rolling cooling rolls generally is controlled at 0～60 μ m, and the DI material is 0～40 μ m.When cold rolling, must on the principle basis of equal proportion convexity, consider the plate shape of band steel, load roll gap shape and supplied materials section configuration are complementary, could guarantee that unit outlet belt plate shape is good.In reality was cold rolling, when the supplied materials convexity changed, fixed as-rolled condition will change, thereby plate shape is changed.Therefore, in order to guarantee plate shape, must adjust the control device of plate shape in real time according to the convexity of supplied materials.

In the control of actual plate shape, methods such as inclination, roller, roll shifting, subregion cooling all are effective plate shape control devices.Wherein roller is important, a real-time control device of plate shape, can change effective convexity of roll, thus the percentage elongation cross direction profiles that changes the shape of load roll gap and roll back band steel.When being with steel to be about to enter cold-rolling mill for one, computer system can start time plate shape precomputation earlier, and calculating can guarantee parameters such as the smooth bending roller force of producing of this band steel, roll shifting amount; And when the band steel enters milling train and produces, can regularly start the back again calculates, according to present actual measurement roll-force, tension force, band steel inlet/outlet thickness and the roll crown (being actual roll shape) that calculates, by calculating the plate shape under the present case, calculate the roller regulated quantity and send to automatic control system and realize best plate shape to adjust bending roller force.

These plate shapes are calculated need use an important parameters: the supplied materials convexity.Because the metal lateral flow is very little in the cold-rolled process, almost can ignore, therefore must carry out intermesh determination and could guarantee that the outlet belt plate shape is good, referring to Fig. 1 according to the principle of equal proportion convexity.That is:

$\frac{C_h}{\stackrel{\‾}{h}}=\frac{C_H}{\stackrel{\‾}{H}}$

Wherein: C _h=h _c-h _e, C _H=H _c-H _e, h and H are respectively the average thickness of outlet and inlet.

As can be seen from the above equation, the supplied materials convexity is set to calculate to whole plate shape and is had crucial effects.Therefore accurately grasping the supplied materials convexity is accurately to set the prerequisite of calculating.

But the convexity of incoming hot rolled slab is not changeless, can fluctuate in certain scope according to process conditions, material situation and the equipment situation of hot rolling.

For solving the accuracy problem of cold rolled sheet shape initialization, obtain supplied materials convexity accurately, the general at present average convexity of transmitting hot-strip from L3 of adopting presets the input value of calculating as plate shape, referring to Fig. 2.But this method has a lot of limitations in actual applications, because the convexity of a hot-strip is inequality from taking the lead to magnetic tape trailer, a band steel is in the operation of rolling, and the convexity on the total length direction fluctuates.This just must cause to set and calculate on the total length direction of a band steel, sometimes may be accurate, inaccurate sometimes.This is feasible for precomputation, because an operation instruction value is just calculated in precomputation earlier; But calculate for the back, its result will control in real time to production, only improperly work as with average convexity, average convexity can not reflect the actual convexity of band steel current location, can cause the load calculated roll gap inaccurate, and then make the bending roller force of calculating can't realize the ideal of exit plate shape is controlled.

At this situation, the processing method that occurs is to set up the convex measuring instrument at the milling train inlet at present, the supplied materials convexity of actual measurement milling train inlet, for example Japanese Nippon Steel patent " the sheet material board-shape control method in the cold-rolled process " (JP2005118840), and then the computing that feedovers, realize the FEEDFORWARD CONTROL of bending roller force, for example day intrinsic safety river motor patent " the plate shape autocontrol method on the cold-rolling mill width " (JP2004154830), referring to Fig. 3.But this method needs extra enhancement measuring instrument, and this instrument measurement position is many, costs an arm and a leg, and safeguards complexity, the cost height.

(3) summary of the invention

The object of the present invention is to provide the processing method of incoming hot rolled slab convexity in a kind of cold rolled sheet shape initialization calculating, this processing method is that the incoming hot rolled slab convexity is reasonably handled, making the hot-strip convexity input value of calculating behind the bending roller force is the convexity of current physical location, makes that bending roller force result of calculation is accurate.

The present invention is achieved in that the processing method of incoming hot rolled slab convexity in a kind of cold rolled sheet shape initialization calculating, it is characterized in that:

The 1st goes on foot, and utilizes the measurement data of hot rolling profile gauge, offers the n of band steel on the total length direction convex value that every needs advance cold-rolling mill;

The 2nd step compensated calculating to n convex value and eliminates the error that preceding operation causes, and the compensating gage point counting is four parts: rewind calculating, crop calculating, straightening compensation and side cut compensation;

The 2.1st step, rewind calculating, coil of strip convexity data are inverted, promptly take the lead to become magnetic tape trailer, magnetic tape trailer becomes takes the lead;

In the 2.2nd step, crop calculates, and some meters length of excision coil of strip head make that c1 is a resection length, and t1 is a total length, and then the coil of strip convexity behind the crop should be:

$c\left[i\right]=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/n}\×(\mathrm{cl}\×\frac{n+1-i}{n})$

The 2.3rd step, the straightening compensation, making the percentage elongation of straightening machine is e, supposes that the band steel evenly extends on width, then convexity becomes:

$c\left[i\right]=\frac{c\left[i\right]}{1+e}$

In the 2.4th step, the compensation of cutting edge makes that monotropic side cut amount is cs, and strip width is w, and then convexity becomes:

$c\left[i\right]={\left(\frac{w-2\×\mathrm{cs}}{w}\right)}^2\×c\left[i\right]$

The 3rd step, according to the rolling position of band steel, to calculate current convexity size and offer precomputation and back calculating as initial conditions, the hot-strip convexity input value that bending roller force precomputation and back are calculated is the convexity of current physical location;

In the 3.1st step, precomputation when the precomputation of each coil of strip, is got first convexity c[1] as initial parameter;

The 3.2nd goes on foot, and back calculating when back calculating starts bending roller force calculating at every turn, according to the hot rolling inlet convexity of this band of position steel of position judgment of being with steel in the present cold-rolling mill, is calculated with this convexity; The convexity that calculates is the convex value of band steel at cold-rolling mill inlet, i.e. the convex value of first frame inlet, and the inlet convexity of all the other frames can be taken into account the influence of plate shape according to equal proportion convexity principle and calculate.

Being implemented as follows of the strip profile value of described cold-rolling mill inlet:

The entrance velocity of order band steel is v, and the time interval of last computation and this calculating is dt, defines a static variable r1, is used to write down the rolling length of this band steel,

(1) gives the r1 assignment

Calculate if there is new band steel to carry out the back, promptly new band steel enters cold-rolling mill,

rl＝0.0

Otherwise, rl=rl+v * dt

(2) obtain this position between any two convex measuring points:

$x=\frac{\mathrm{rl}}{\mathrm{tl}}\×n$

X is one and gets the maximum integer i that is less than or equal to x greater than 0 floating number, and then this position is positioned at that (i is i+1) between two convex measuring points;

(3) obtain the strip profile of this position

Because the supplied materials convexity slowly changes in the longitudinal direction, can suppose (i, i+1) convexity between two convex measuring points is linear change, so the convexity of this position is:

$\mathrm{cr}=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/n}\×(x-i)$

Cr is the convex value of band steel at the cold-rolling mill inlet, the i.e. convex value of first frame inlet.

A described n measurement point is equally distributed, and n is measured convex value is 30.

The present invention transmits the segmentation convexity data of coming according to hot rolling, calculate the error that the preceding operation of elimination causes by compensation, rolling position according to the band steel, calculate current convexity size and offer precomputation and back calculating as initial conditions, the hot-strip convexity input value that bending roller force precomputation and back are calculated is the convexity of current physical location, make that bending roller force result of calculation is accurate, reach the purpose of on band steel total length, accurately setting.

Compared with prior art, main feature of the present invention is to obtain the initial conditions that revised actual convexity is calculated as bending roller force according to supplied materials current length position calculation, the section configuration of load calculated roll gap and supplied materials is complementary, thereby guarantees according to the plate shape of this bending roller force control good.And complicated, expensive convex measuring instrument need be installed before cold-rolling mill, and saved investment, reduced cost.

(4) description of drawings

The invention will be further described below in conjunction with the drawings and specific embodiments.

Fig. 1 is the schematic diagram of equal proportion convexity;

Fig. 2 is existing average convexity transmission method schematic diagram;

Fig. 3 is existing actual measurement convexity feed forward control method schematic diagram;

Fig. 4 is an incoming hot rolled slab convex measuring value distribution map of the present invention (n=30);

Fig. 5 transmits for convexity segmentation of the present invention and adds compensation computational methods schematic diagram;

Fig. 6 is the curve map of embodiment strip profile.

(5) specific embodiment

The present invention utilizes the measurement data of hot rolling profile gauge, carries out certain data and handles, and is delivered to cold rollingly by L3, and calculating for cold rolling setting provides suction parameter accurately.Because the convex measuring instrument of complexity, precision is housed behind the finishing mill of hot rolling, be used to carry out real-time convex measuring to realize the convexity closed-loop control.

The processing method of incoming hot rolled slab convexity the steps include: during a kind of cold rolled sheet shape initialization calculated

The 1st goes on foot, and utilizes the measurement data of hot rolling profile gauge, offers the n of band steel on the total length direction convex value that every needs advance cold-rolling mill; This n value along take the lead to the distribution situation of magnetic tape trailer as shown in Figure 4, be equally distributed along this n of band steel length direction measurement point, n measurement convex value is 30.

The 2nd step, n convex value compensated calculating eliminate the error that preceding operation causes, though, on pickling and cold continuous rolling production line, will be subjected to the influence of operations such as crop, straightening, pickling, side cut when hot rolling is measured because the position of n convex measuring value of a band steel is accurately; The compensating gage point counting is four parts: rewind calculating, crop calculating, straightening compensation and the compensation of cutting edge; Referring to Fig. 5

The 2.1st step, rewind calculating, because of the magnetic tape trailer of incoming hot rolled slab is cold rolling taking the lead, coil of strip convexity data need be inverted, promptly take the lead to become magnetic tape trailer, magnetic tape trailer becomes takes the lead;

Known incoming hot rolled slab length L, n along its length (supposition n is 30) strip profile value is kept at array c[30] in, array dimension is 30;

Array tc[30 in the middle of setting up], make following assignment:

tc[i]＝c[30-i]

Back substitution then:

c[i]＝tc[i]；

In the 2.2nd step, crop calculates, and when rolling up on cold rolling, some meters length of topping, therefore will deduct this part length in convexity is calculated; Make that c1 is a resection length, t1 is a total length, and then the coil of strip convexity behind the crop should be:

$c\left[i\right]=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/30}\×(\mathrm{cl}\×\frac{30+1-i}{30})$

The 2.3rd step, the straightening compensation, the straightening machine before the pickling generally has 1% to 3% percentage elongation, also can change strip profile, therefore needs compensation to calculate; Making the percentage elongation of straightening machine is e, supposes that the band steel evenly extends on width, and then convexity becomes:

$c\left[i\right]=\frac{c\left[i\right]}{1+e}$

The 2.4th step, the compensation of cutting edge, most of coil of strip needs to cut edge before rolling and handles, and therefore also needs the compensation of cutting edge; Make that monotropic side cut amount is cs, strip width is w, and then convexity becomes:

${c\left[i\right]=\left(\frac{w-2\×\mathrm{cs}}{w}\right)}^2\×c\left[i\right]$

The 3rd step, according to the rolling position of band steel, to calculate current convexity size and offer precomputation and back calculating as initial conditions, the hot-strip convexity input value that bending roller force precomputation and back are calculated is the convexity of current physical location;

In the 3.1st step, precomputation when the precomputation of each coil of strip, is got first convexity c[1] as initial parameter;

The 3.2nd goes on foot, and back calculating when back calculating starts bending roller force calculating at every turn, according to the hot rolling inlet convexity of this band of position steel of position judgment of being with steel in the present cold-rolling mill, is calculated with this convexity; The convexity that calculates is the convex value of band steel at cold-rolling mill inlet, i.e. the convex value of first frame inlet, and the inlet convexity of all the other frames can be taken into account the influence of plate shape according to equal proportion convexity principle and calculate.

Being implemented as follows of the strip profile value of cold-rolling mill inlet:

The entrance velocity of order band steel is v, and the time interval of last computation and this calculating is dt, defines a static variable r1, is used to write down the rolling length of this band steel,

(1) gives the r1 assignment

Calculate if there is new band steel to carry out the back, promptly new band steel enters cold-rolling mill,

rl＝0.0

Otherwise, rl=rl+v * dt

(2) obtain this position between any two convex measuring points:

$x=\frac{\mathrm{rl}}{\mathrm{tl}}\×n$

X is one and gets the maximum integer i that is less than or equal to x greater than 0 floating number, and then this position is positioned at that (i is i+1) between two convex measuring points;

(3) obtain the strip profile of this position

Because the supplied materials convexity slowly changes in the longitudinal direction, can suppose (i, i+1) convexity between two convex measuring points is linear change, so the convexity of this position is:

$\mathrm{cr}=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/n}\×(x-i)$

Cr is the convex value of band steel at the cold-rolling mill inlet, the i.e. convex value of first frame inlet.

Embodiment

In certain cold continuous rolling three electric transformation project, the supplied materials convexity of bending roller force model is handled by the present invention, can realize the automatic setting of bending roller force, and plate shape is all right.

The example that convexity is handled is as follows:

It is as shown in table 1 to suppose that convexity numerical value is measured in hot rolling;

Table 1

40.00	42.39	44.20	44.98	44.54	42.99	40.70	38.24	36.216	35.11
										35.20	36.47	38.60	41.07	43.28	44.69	44.94	43.99	42.06	39.62
37.27	35.60	35.00	35.62	37.31	39.66	42.10	44.01	44.95	44.67

Suppose coil of strip length overall 500m, crop 10m.Straightening extends 3%, strip width 800mm, and one-sided side cut 20mm, the strip profile after then calculating through compensation becomes table 2, and the curve map of strip profile is referring to Fig. 6.

When being rolled down to 320m,

$x=\frac{\mathrm{rl}}{\mathrm{tl}}\×30=\frac{320}{500}\×30=19.2$

Then Ci Shi rolling position tables look-up 2 between the 19th and the 20th; The actual convexity of this moment is:

$\mathrm{cr}=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/30}\×(x-i)=31.95+\frac{30.84-31.95}{500/30}\×(19.2-19)=31.94$

If only adopt the average convexity 40.52 of supplied materials, then be with the error that produces according to conventional method:

$\frac{40.52-31.94}{31.94}\×100\%=26.9\%$

As seen adopt method of the present invention can improve plate shape setting accuracy greatly.

Table 2

The position	Initial data	Rewind calculating	Crop calculates	The straightening compensation	Cut edge and compensate
						1	40.00	44.67	44.68	43.37	39.15
2	42．39	44.95	44.93	43.62	39.37
						3	44.20	44.01	43.97	42.69	38.53
4	44.98	42.10	42.06	40.83	36.85
						5	44.54	39.66	39.62	38.47	34.71
6	42.99	37.31	37.28	36.20	32.67
						7	40.70	35.62	35.61	34.57	31.20
8	38.24	35.00	35.01	33.99	30.68
						9	36.21	35.60	35.62	34.59	31.21
10	35.11	37.27	37.30	36.22	32.69
						11	35.20	39.62	39.65	38.50	34.74
12	36.47	42.06	42.08	40.86	36.87
						13	38.60	43.99	44.00	42.72	38.55
14	41.07	44.94	44.94	43.63	39.37
						15	43.28	44.69	44.67	43.37	39.14
16	44.69	43.28	43.26	42.00	37.90
						17	44.94	41.07	41.05	39.85	35.97
18	43.99	38.60	38.58	37.46	33．81
						19	42.06	36.47	36.46	35.40	31.95
20	39.62	35.20	35.20	34.17	30.84
						21	37.27	35．11	35.12	34.09	30.77
22	35.60	36.21	36.22	35.17	31.74
						23	35.00	38.24	38.25	37.14	33.52
24	35.62	40.70	40.71	39.52	35.67
						25	37.31	42.99	43.00	41.74	37.67
26	39.66	44.54	44.54	43.24	39.03
						27	42.10	44.98	44.98	43.67	39.41
28	44.01	44.20	44.20	42.91	38.73
						29	44.95	42.39	42.39	41.15	37.14
30	44.67	40.00	40.00	38.83	35.05
						On average	40.52	40.52	40.51	39.33	35.50

Claims (3)

1. the processing method of incoming hot rolled slab convexity during a cold rolled sheet shape initialization calculates is characterized in that:

The 1st goes on foot, and utilizes the measurement data of hot rolling profile gauge, offers the n of band steel on the total length direction convex value that every needs advance cold-rolling mill;

The 2nd step compensated calculating to n convex value and eliminates the error that preceding operation causes, and the compensating gage point counting is four parts: rewind calculating, crop calculating, straightening compensation and side cut compensation;

The 2.1st step, rewind calculating, coil of strip convexity data are inverted, promptly take the lead to become magnetic tape trailer, magnetic tape trailer becomes takes the lead;

In the 2.2nd step, crop calculates, and some meters length of excision coil of strip head make that cl is a resection length, and tl is a total length, and then the coil of strip convexity behind the crop should be:

$c\left[i\right]=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/n}\×(\mathrm{cl}\×\frac{n+1-i}{n})$

The 2.3rd step, the straightening compensation, making the percentage elongation of straightening machine is e, supposes that the band steel evenly extends on width, then convexity becomes:

$c\left[i\right]=\frac{c\left[i\right]}{1+e}$

In the 2.4th step, the compensation of cutting edge makes that monotropic side cut amount is cs, and strip width is w, and then convexity becomes:

$c\left[i\right]={\left(\frac{w-2\×\mathrm{cs}}{w}\right)}^2\×c\left[i\right]$

The 3rd step, according to the rolling position of band steel, to calculate current convexity size and offer precomputation and back calculating as initial conditions, the hot-strip convexity input value that bending roller force precomputation and back are calculated is the convexity of current physical location;

In the 3.1st step, precomputation when the precomputation of each coil of strip, is got first convexity c[1] as initial parameter;

The 3.2nd goes on foot, and back calculating when back calculating starts bending roller force calculating at every turn, according to the hot rolling inlet convexity of this band of position steel of position judgment of being with steel in the present cold-rolling mill, is calculated with this convexity; The convexity that calculates is the convex value of band steel at cold-rolling mill inlet, i.e. the convex value of first frame inlet, and the inlet convexity of all the other frames can be taken into account the influence of plate shape according to equal proportion convexity principle and calculate.

2. the processing method of incoming hot rolled slab convexity during cold rolled sheet shape initialization according to claim 1 calculates is characterized in that: being implemented as follows of the strip profile value of cold-rolling mill inlet:

The entrance velocity of order band steel is v, and the time interval of last computation and this calculating is dt, defines a static variable rl, is used to write down the rolling length of this band steel;

(1) gives the rl assignment

Calculate if there is new band steel to carry out the back, promptly new band steel enters cold-rolling mill,

rl＝0.0

Otherwise, rl=rl+v * dt

(2) obtain this position between any two convex measuring points:

$x=\frac{\mathrm{rl}}{\mathrm{tl}}\×n$

X is one and gets the maximum integer i that is less than or equal to x greater than 0 floating number, and then this position is positioned at that (i is i+1) between two convex measuring points;

(3) obtain the strip profile of this position

Because the supplied materials convexity slowly changes in the longitudinal direction, can suppose (i, i+1) convexity between two convex measuring points is linear change, so the convexity of this position is:

$\mathrm{cr}=c\left[i\right]+\frac{c[i+1]-c\left[i\right]}{\mathrm{tl}/n}\×(x-i)$

Cr is the convex value of band steel at the cold-rolling mill inlet, the i.e. convex value of first frame inlet.

3. the processing method of incoming hot rolled slab convexity during cold rolled sheet shape initialization according to claim 1 calculates, it is characterized in that: n measurement point is equally distributed, n is measured convex value is 30.

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