CN103920719A - Method for controlling convexity of hot rolled plate shape - Google Patents

Abstract

The invention discloses a method for controlling a convexity of a hot rolled plate shape. The method includes steps of S100, calculating a convexity deviation of strip steel output from an outlet of a finishing mill group in a current control period; S200, calculating distribution convexity deviations of preceding six finishing mill racks in the finishing mill group according to the obtained convexity deviation; S300, calculating a bending roll adjusting amount of each finishing mill rack and adjusting a roll bending force of each finishing mill rack. According to the method for controlling the convexity of the hot rolled plate shape, the convexity of the hot rolled strip steel can be real-timely and dynamically controlled, and the adjustment is accurate and stable.

Description

The convex degree control method of hot rolled plate shape

Technical field

The present invention relates to the hot rolled plate shape of iron and steel in producing and control, more particularly, is a kind of convex degree control method for hot rolled plate shape that hot rolling strip profile is controlled.

Background technology

Along with the technological progress of steel production enterprise and improving constantly of end user's requirement, the size of Strip, presentation quality are proposed to high request.Plate shape is an important quality index of hot-strip, comprises in general section configuration (Profile) and flatness control (Flatness) two aspects.Section configuration, generally by convexity, the isoparametric formulations of wedge shape degree, wherein be take again convexity as main control parameters.In the hot strip steel rolling operation of rolling, with the actual profile shape of steel, not to be often complete rectangular shape, its middle part and limit portion be total there is to a certain degree thick poor, thisly with the difference between steel interior thickness and limit portion thickness, is called as strip profile.And glacing flatness generally represents with relative extension difference or anxious high degree (claiming angularity).Therefore the main task that, hot rolled plate shape is controlled is exactly that to realize convexity and the glacing flatness of hot-strip good.

The plate shape Crown control of domestic iron and steel enterprises hot-strip is mainly to utilize the methods such as CVC milling train, PC milling train, positive and negative roller, working roll roll shifting control to realize at present, and aspect in real time plate shape monitoring and adjustment, be mainly to take operating personnel's manual intervention bending roller force as main, lack quantitative criteria accurately.

Granted publication number is controlled method for the patent of invention of CN1253251C discloses shape wave in a kind of hot-strip, it is mainly unrestrained profile shape controlling method in adopting, unrestrained PSCU setup control during band steel head is adopted, to its rear section, adopt wave in dynamic ASC to control, to solve hot-strip because of the cooling bilateral unrestrained defect causing.

Granted publication number discloses a kind of hot-strip convex degree control method based on smooth change rolling procedure for the patent of invention of CN100443205C, it adopts and seamlessly transits function structure each frame is depressed to power adjustment, thereby reaches the control to strip profile and glacing flatness.

Summary of the invention

Object of the present invention, is to provide a kind of convex degree control method of the hot rolled plate shape that can control strip profile in hot rolling.

The convex degree control method of hot rolled plate shape of the present invention, for in a plurality of control cycles, to carry out the band steel of finish rolling processing by mm finishing mill unit, carry out Crown control, described mm finishing mill unit comprises seven smart frame F1 ~ F7, band steel passes through mm finishing mill unit entrance successively after these seven finishing stand rollings, by mm finishing mill unit outlet output, the method comprises the following steps:

A, in current control cycle, to detecting from the actual convexity with steel of this mm finishing mill unit outlet output, and according to target convexity, calculates the convexity deviation d in the current rolling cycle _{cm (k)};

B, according to the convexity deviation in current control cycle, utilizes following formula to calculate the distribution convexity deviation e separately of the first six finishing stand F1 ~ F6 in described mm finishing mill unit ₁(k) ~ e ₆(k):

$e_i\left(k\right)=\frac{0.8\·d_{\mathrm{cm}}\left(k\right)}{\underset{i=6}{\overset{i}{\mathrm{\Π}}}\mathrm{eata}\left(i\right)},$

Wherein, e _i(k) be i(i=1 in current control cycle, 2,3,4,5,6) the distribution convexity deviation of frame, eata is (i) the convexity coefficient of heredity of i frame;

C, according to the distribution convexity deviation e of the first six finishing stand F1 ~ F6 in described mm finishing mill unit ₁~ e ₆, to this, in the first six finishing stand, the bending roller force of each finishing stand is adjusted, the roller adjustment amount Δ F of each finishing stand in this first six finishing stand in current control cycle _bi(k) be:

${\mathrm{\ΔF}}_{\mathrm{Bi}}\left(k\right)=K_{a2i}[K_{\mathrm{pi}}{e}_i\left(k\right)+K_{\mathrm{Ii}}\underset{j=1}{\overset{k}{\mathrm{\Σ}}}{e}_i\left(j\right)]/K_C,$

Wherein, K _a2ifor crown feedback, control model and adjust coefficient, the crown feedback proportionality coefficient that Kpi is i frame, K _iibe the crown feedback integral coefficient of i frame, K _cfor the influence coefficient of bending roller force to convexity.

Preferably, eata(i) by following formula, calculate:

eata[i]＝cetb[i](1.0-zeta[i])（1.0-ε），

Wherein, cetb[i] be adjustment factor, ε is relative volume under pressure, zeta[i] be the output layer being gone out by neural computing.

The convex degree control method of hot rolled plate shape of the present invention, can carry out real-time dynamic control to the convexity of hot-strip, and adjusts accurate, stable.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of the convex degree control method of hot rolled plate shape of the present invention.

The specific embodiment

Below with reference to the accompanying drawings and the specific embodiment, the process step of the convex degree control method of hot rolled plate shape of the present invention is elaborated.

On the whole, the convex degree control method of hot rolled plate shape of the present invention, in a plurality of control cycles, carries out Crown control to carry out the band steel of finish rolling processing by mm finishing mill unit.And mm finishing mill unit comprises seven smart frame F1 ~ F7, band steel passes through mm finishing mill unit entrance successively after these seven finishing stand rollings, by mm finishing mill unit outlet output.In conjunction with Fig. 1, haply, the method comprising the steps of S100-S300, wherein, in step S100, calculates the convexity deviation of mm finishing mill unit outlet output strip in current control cycle; In step S200, according to the convexity deviation of gained, calculate the first six finishing stand in mm finishing mill unit and must distribute convexity deviation separately; In step S300, calculate the roller adjustment amount of each finishing stand, and its bending roller force is adjusted.Below each step is described in more detail.

step S100.

In step S100, in current control cycle, to detecting from the actual convexity with steel of this mm finishing mill unit outlet output, and according to target convexity, calculate the convexity deviation d in the current rolling cycle _{cm (k)}.

Actual convex measuring to output strip, can utilize profile gauge to complete, and then actual convex value and target convexity is compared, and the difference of gained is convexity deviation d _{cm (k)}.

step S200.

In step S200, according to the convexity deviation in current control cycle, utilize following formula to calculate the distribution convexity deviation e separately of the first six finishing stand F1 ~ F6 in described mm finishing mill unit ₁(k) ~ e ₆(k):

$e_i\left(k\right)=\frac{0.8\·d_{\mathrm{cm}}\left(k\right)}{\underset{i=6}{\overset{i}{\mathrm{\Π}}}\mathrm{eata}\left(i\right)},$ (formula 1)

In above-mentioned formula 1, e _i(k) be i(i=1 in current control cycle, 2,3,4,5,6) the distribution convexity deviation of frame, eata is (i) the convexity coefficient of heredity of i frame.

More specifically, the convexity coefficient of heredity eata of i frame (i) can draw by conventional convexity precomputation model.In an embodiment of the invention, eata (i) can calculate by following formula:

Eata[i]=cetb[i] (1.0-zeta[i]) (1.0-ε); (formula 2)

In formula 2, cetb[i] be adjustment factor, it is the preset value for each frame, ε is relative volume under pressure (being the ratio of each frame thickness difference and this frame inlet thickness), zeta[i] output layer that calculates of the conventional neural network algorithm of serving as reasons.More specifically, in neural computing, network is input as strip width, inlet thickness, volume under pressure, work roll diameter, roll-force and apart from limit portion position relatively, by conventional neural network algorithm, calculates the zeta[i as output layer].

Of the present invention one preferred embodiment in, cetb[i] value be preferably arranged between 0.9 to 1.1, and the zeta[i being calculated by neural network algorithm] number range between 0.25-0.5.

step S300.

In step S300, according to the distribution convexity deviation e of the first six finishing stand F1 ~ F6 in mm finishing mill unit ₁~ e ₆to this, in the first six finishing stand, the bending roller force of each finishing stand is adjusted, the adjustment of each frame adopts PI to control (being proportional plus integral control) means, particularly, and the roller adjustment amount Δ F of each finishing stand in this first six finishing stand in current control cycle _bi(k) be:

${\mathrm{\ΔF}}_{\mathrm{Bi}}\left(k\right)=K_{a2i}[K_{\mathrm{pi}}{e}_i\left(k\right)+K_{\mathrm{Ii}}\underset{j=1}{\overset{k}{\mathrm{\Σ}}}{e}_i\left(j\right)]/K_C,$ (formula 3)

Wherein, K _a2ifor crown feedback, control model and adjust coefficient, the crown feedback proportionality coefficient that Kpi is i frame, K _iibe the crown feedback integral coefficient of i frame, K _cfor the influence coefficient of bending roller force to convexity.

When calculating the roller adjustment amount Δ F of each finishing stand _bi(k) after, can utilize work roll bending control system, the bending roller force of each finishing stand is adjusted.Roll bending control system can utilize conventional bending roller force control device to realize.For example, in a kind of existing roll bending control system, comprise a hydraulic system, it has Electromagnetic Control and digital closed loop adjuster.And this system also comprises the electro-hydraulic valve being arranged on working roll oil steel, bootable liquid flows into or efflux cylinder pressure.System is according to roller adjustment amount Δ F _bi(k), the electric current in control loop is regulated, and then by electro-hydraulic valve, control in hydraulic system to the amount of liquid that flows into or flow out in hydraulic cylinder, thereby bending roller force is adjusted.Certainly, easily understand, the adjustment of bending roller force, also can be undertaken by other means of conventional use in industry.

Easily understand, utilizing above-mentioned steps to realize in the process of Crown control, the adjustment amount of each frame bending roller force need to be considered the maximum conditions of equipment.In addition, this flow process should normally be worked and band steel be detected at profile gauge and be started after by signal, and the cycle of whole flow process and profile gauge detected the cycle of convexity signal about 2 seconds.

In sum, the convex degree control method of hot rolled plate shape of the present invention, can carry out real-time dynamic control to the convexity of hot-strip, and adjusts accurate, stable.

Claims (2)

1. the convex degree control method of a hot rolled plate shape, for in a plurality of control cycles, to carry out the band steel of finish rolling processing by mm finishing mill unit, carry out Crown control, described mm finishing mill unit comprises seven smart frame F1 ~ F7, band steel passes through mm finishing mill unit entrance successively after these seven finishing stand rollings, by mm finishing mill unit outlet output, it is characterized in that, the method comprises the following steps:

A, in current control cycle, to detecting from the actual convexity with steel of this mm finishing mill unit outlet output, and according to target convexity, calculates the convexity deviation d in the current rolling cycle _{cm (k)};

B, according to the convexity deviation in current control cycle, utilizes following formula to calculate the distribution convexity deviation e separately of the first six finishing stand F1 ~ F6 in described mm finishing mill unit ₁(k) ~ e ₆(k):

$e_i\left(k\right)=\frac{0.8\·d_{\mathrm{cm}}\left(k\right)}{\underset{i=6}{\overset{i}{\mathrm{\Π}}}\mathrm{eata}\left(i\right)},$

Wherein, e _i(k) be i(i=1 in current control cycle, 2,3,4,5,6) the distribution convexity deviation of frame, eata is (i) the convexity coefficient of heredity of i frame;

C, according to the distribution convexity deviation e of the first six finishing stand F1 ~ F6 in described mm finishing mill unit ₁~ e ₆, to this, in the first six finishing stand, the bending roller force of each finishing stand is adjusted, the roller adjustment amount Δ 1F of each finishing stand in this first six finishing stand in current control cycle _bi(k) be:

${\mathrm{\ΔF}}_{\mathrm{Bi}}\left(k\right)=K_{a2i}[K_{\mathrm{pi}}{e}_i\left(k\right)+K_{\mathrm{Ii}}\underset{j=1}{\overset{k}{\mathrm{\Σ}}}{e}_i\left(j\right)]/K_C,$

Wherein, K _a2ifor crown feedback, control model and adjust coefficient, the crown feedback proportionality coefficient that Kpi is i frame, K _iibe the crown feedback integral coefficient of i frame, K _cfor the influence coefficient of bending roller force to convexity.

2. the convex degree control method of hot rolled plate shape according to claim 1, is characterized in that, eata (i) calculates by following formula:

eata[i]＝cetb[i](1.0-zeta[i])（1.0-ε），

Wherein, cetb[i] be adjustment factor, ε is relative volume under pressure, zeta[i] be the output layer being gone out by neural computing.