COMPENSATION METHOD FOR ASYMMETRIC PLATE PROFILE OF PLATE/STRIP ROLLING MILL

Abstract

A compensation method of an asymmetric strip shape of a strip rolling mill, for compensating the asymmetric strip shape of a strip caused in a machining process of the strip rolling mill in the prior art. The compensation method is realized by generating a non-linear asymmetric no-load roll-shaped profile curve through polishing an upper working roll and a lower working roll of a rolling mill and forming a non-linear asymmetric no-load roll gap between a transmission side and a working side of the upper and lower working rolls. The strip rolling mill in the prior art refers to a presently commonly used two-roll rolling mill driven by the transmission side of the working roll, a four-roll rolling mill equipped with a support roll and a multi-roll rolling mill equipped with a middle roll.

Claims

1-6. (canceled)

7. A compensation method for an asymmetric plate profile of a plate/strip rolling mill for compensating an asymmetric profile of a plate/strip rolled in plate/strip rolling, characterized in that: the compensation method is achieved by a non-linear asymmetric no-load roll gap of a transmission side and an operation side between an upper work roll and a lower work roll; the asymmetric no-load roll gap is obtained by a non-linear asymmetric no-load roll contour profile curve corresponding to the upper work roll and the lower work roll; the non-linear asymmetric no-load roll contour profile curve includes a differentiated degree of asymmetry between the upper work roll and the lower work roll, and grinding only one of the upper work roll or the lower work roll of the rolling mill with non-linear asymmetric roll contour profile curve; the non-linear asymmetric no-load roll gap height curve formed between the upper and lower work rolls includes a three or higher order polynomial equation, wherein an axial coordinate of a roller is used as a variable of the polynomial equation, and a coefficient of a highest odd-ordered term is not zero, the polynomial equation is described by equation (1) as below:
Gap(x)=Gap.sub.0+G.sub.1.Math.x.sup.1+G.sub.2.Math.x.sup.2+G.sub.3.Math.x.sup.3+ . . . +G.sub.n.Math.x.sup.n(1) wherein, x is the coordinate of a roll body of the work roll in the axial direction with the center of the roll body as the origin of the coordinate system; Gap.sub.0 is a set value of a roll gap with the center of the roll body as the origin of the coordinate system; G.sub.1, G.sub.2, G.sub.3, . . . G.sub.n are the coefficients of the polynomial equation, and each of G.sub.1, G.sub.2, G.sub.3, . . . G.sub.n range from 1 to 1; n is no less than 3; the non-linear asymmetric no-load roll contour profile curve is a three or higher order polynomial equation corresponding to the equation: Gap(x)=Gap.sub.0+G.sub.1.Math.x.sup.1+G.sub.2.Math.x.sup.2+G.sub.3.Math.x.sup.3+ . . . +G.sub.n.Math.x.sup.n, wherein an axial coordinate of a roller is used as a variable of the polynomial equation.

8. The compensation method for an asymmetric plate profile of a plate/strip rolling mill according to claim 7, wherein, the polynomial equation comprises the follows: (1) a lower profile curve of the upper work roll with respect to a center line of the roller is described by the formula (2) as follows:
S.sub.WU(x)=A.sub.3.Math.x.sup.3+A.sub.2.Math.x.sup.2+A.sub.1.Math.xA.sub.0(2) wherein, x is the coordinate of the roll body of the work roll in the axial direction with the center of the roll body as the origin of the coordinate system; A.sub.0 is the radius of the roll body with the center of the roll body of the work roll as the origin of the coordinate system; A.sub.1 is a linear asymmetric parameter of a roll contour profile curve of the work roll, and the value of A.sub.1 can be determined by formula (3):
A.sub.1=K.sub.1+K.sub.2.Math.Bp+K.sub.3.Math.Br+K.sub.4.Math.Br/Bp+K.sub.5/R.sup.3+K.sub.6.Math.Tq(3) wherein, Bp is the width of a rolled piece with the unit of meter; Br is the length of a surface of the work roll with the unit of meter; R is the nominal radius of the work roll with the unit of meter; Tq is an on-load average torque of the work roll with the unit of KN.Math.m; K.sub.1, K.sub.2, K.sub.3, K.sub.4, K.sub.5, and K.sub.6 are adjustment parameters, and each of the adjustment parameters ranges from 1 to 1; A.sub.2 is a symmetry parameter of the roll contour profile curve of the work roll, and the value of A.sub.2 can be determined by the formula (4):
A.sub.2=M.sub.1+M.sub.2.Math.Bp+M.sub.3.Math.Br+M.sub.4.Math.Br/Bp+M.sub.5/R.sup.3+M.sub.6.Math.Tq(4) wherein, Bp is the width of the rolled piece with the unit of meter; Br is the length of the roll body of the work roll with the unit of meter; R is the nominal radius of the work roll with the unit of meter; Tq is the on-load average torque of the work roll with the unit of KN.Math.m; M.sub.1, M.sub.2, M.sub.3, M.sub.4, M.sub.5, and M.sub.6 are adjustment parameters, and each of the adjustment parameters ranges from 1 to 1; A.sub.3 is a non-linear asymmetric parameter of the roll contour profile curve of the work roll, and the value of A.sub.3 can be determined by formula (5):
A.sub.3=N.sub.1+N.sub.2.Math.Bp+N.sub.3.Math.Br+N.sub.4.Math.Br/Bp+N.sub.5/R.sup.3+N.sub.6.Math.Tq(5) wherein, Bp is the width of the rolled piece with the unit of meter; Br is the length of the roll body of the work roll with the unit of meter; R is the nominal radius of the work roll with the unit of meter; Tq is the on-load average torque of the work roll with the unit of KN.Math.m; N.sub.1, N.sub.2, N.sub.3, N.sub.4, N.sub.5, and N.sub.6 are adjustment parameters, and each of the adjustment parameters ranges from 1 to 1; (2) an upper profile curve of the lower work roll with respect to the center line of the roller is described by formula (6) as follows:
S.sub.WD(x)=B.sub.3.Math.x.sup.3B.sub.2.Math.x.sup.2B.sub.1.Math.x+B.sub.0(6) wherein, conditions of B.sub.3, B.sub.2, B.sub.1, B.sub.0 are the same as described above; (3) the lower profile roll contour curve of the upper work roll and the upper profile roll contour curve of the lower work roll of the rolling mill are superposed in a coordinate system to obtain a new no-load roll gap height superposing curve formula (7) of the upper work roll and the lower work roll as follows:
Gap(x)=(A.sub.3+B.sup.3).Math.x.sup.3+(A.sub.2+B.sub.2).Math.x.sup.2+(A.sub.1+B.sub.1).Math.x+Gap.sub.0(7) wherein, x is the coordinate of the roll body of the work roll in the axial direction with the center of the roll body as the origin of the coordinate system; and Gap.sub.0 is a set value of a roll gap with the center of the roll body as the origin of the coordinate system.

9. The compensation method for an asymmetric plate profile of a plate/strip rolling mill of claim 7, wherein, non-linear asymmetric no-load roll contour profile curve and the no-load roll gap height curve of the plate/strip rolling mill are applied to the rolling mill independently.

10. The compensation method for an asymmetric plate profile of a plate/strip rolling mill of claim 7, wherein, after the non-linear asymmetric no-load roll contour profile curve is superimposed on a roll thermal convexity compensation curve, a continuously variable convexity curve, and/or other roll contour profile curves currently used by the rolling mill, a new asymmetric no-load roll contour profile curve and roll gap height curve are formed for application; the new asymmetric no-load roll contour profile curve satisfies the conditions of claim 7.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. 1 is a diagram showing the lower profile curve of the upper work roll and the upper profile roll contour curve of the lower work roll of the present invention in a coordinate system.

[0053] FIG. 2 is an exploded view of the roll gap height set curve of the present invention.

[0054] In the drawings, 1 is the lower profile curve of the upper work roll of the rolling mill, 2 is the upper profile roll contour curve of the lower work roll, 3 is the straight line that indicates the maximum value of the no-load roll gap, 4 is the line that connects the maximum value and the minimum value of the no-load roll gap, 5 is the height curve of the no-load roll gap.

DETAILED DESCRIPTION OF THE INVENTION

[0055] In order to fully understand the objectives, features, and functions of the present invention, the present invention will be described in detail with reference to the following embodiments. However, the present invention is not limited hereto.

[0056] The present invention provides a compensation method for asymmetric plate profile of plate/strip rolling mill. The work roll profile is grinded with a specific curve to obtain an asymmetric set roll gap of the transmission side and the operation side between the upper work roll and the lower work roll. The asymmetric plate profile produced by the processing of the metal plate/strip is compensated and controlled, such that a series of problems, i.e., deviation, tail flick, asymmetric plate profile, etc., during the rolling process can be avoided.

[0057] The asymmetric plate profile mentioned in the present invention refers to the common phenomenon of asymmetric distribution of the thickness of the left and right sides of the plate/strip and the asymmetric waves of the plate/strip (or potential waves) during the rolling process of the plate/strip by the rolling mill under the current technical conditions.

[0058] The deviation mentioned in the present invention refers to the phenomenon where the rolled piece is curved toward the operation side or the transmission side of the rolling mill with respect to the rolling center line during the rolling process.

[0059] The tail flick mentioned in the present invention refers to the phenomenon where during the rolling process after the tail portion of the rolled plate goes out of the rolling mill, the rolled plate cannot move normally, thereby causing swings and jumps. The rolled plate under this condition enters the next machine, which results in the tail portion of the rolled plate being folded, broken, etc.

[0060] The compensation method for the asymmetric plate profile of the plate/strip rolling mill of the present invention will be described in detail hereafter.

[0061] A compensation method for asymmetric plate profile of plate/strip rolling mill is provided. At least one of the upper work roll and the lower work roll of the rolling mill is grinded with a non-linear asymmetric roll contour curve, so that a non-linear asymmetric roll gap height curve of the transmission side and the operation side is formed between the upper work roll and the lower work roll.

[0062] The non-linear asymmetric no-load roll contour profile curve is a polynomial cubic formula or a polynomial formula of higher degree using the axial coordinate of the roll as the variable. The non-linear asymmetric no-load roll gap height curve formed between the upper work roll and the lower work roll is also a polynomial cubic formula or a polynomial formula of higher degree using the axial coordinate of the roll as the variable.

[0063] A simple and practical method to implement and achieve the intended object of the present invention is to describe the non-linear asymmetric no-load roll contour profile curve as a one-variable cubic polynomial like formula (1) and (5), and describe the non-linear asymmetric roll gap formed between the upper work roll and the lower work roll as a one-variable cubic polynomial like formula (6). The specific implementation process conforms to the following description: [0064] (1) The lower profile curve of the upper work roll with respect to a center line of the roll is described by the formula (1) as follows:

S.sub.WU(x)=A.sub.3.Math.x.sup.3+A.sub.2.Math.x.sup.2+A.sub.1.Math.x[[]]+A.sub.0(1) [0065] wherein, [0066] x is the coordinate of the roll body of the work roll in the axial direction with the center of the roll body as the origin of the coordinate system; [0067] A.sub.0 is the radius of the roll body with the center of the roll body of the work roll as the origin of the coordinate system; [0068] A.sub.1 is the linear asymmetric parameter of the roll contour profile curve of the work roll. The value of A.sub.1 can be determined by formula (2):

A.sub.1=K.sub.1+K.sub.2.Math.Bp+K.sub.3.Math.Br+K.sub.4.Math.Br/Bp+K.sub.5/R.sup.3+K.sub.6.Math.Tq(2) [0069] wherein, [0070] Bp is the width of the rolled piece with the unit of meter; [0071] Br is the length of the work roll surface with the unit of meter, [0072] R is the nominal radius of the work roll with the unit of meter, [0073] Tq is the on-load average torque of the work roll with the unit of KNm; [0074] K.sub.1, K.sub.2, K.sub.3, K.sub.4, K.sub.5, and K.sub.6 are the adjustment parameters, and the adjustment parameters range from 1 to 1; [0075] A.sub.2 is the symmetry parameter of the roll contour profile curve of the work roll, and the value of A.sub.2 the can be determined by the formula (3):

A.sub.2=M.sub.1+M.sub.2.Math.Bp+M.sub.3.Math.Br+M.sub.4.Math.Br/Bp+M.sub.5/R.sup.3+M.sub.6.Math.Tq(3) [0076] wherein, [0077] Bp is the width of the rolled piece with the unit of meter; [0078] Br is the length of the roll body of the work roll with the unit of meter; [0079] R is the nominal radius of the work roll with the unit of meter, [0080] Tq is the on-load average torque of the work roll with the unit of KN.Math.m; [0081] M.sub.1, M.sub.2, M.sub.3, M.sub.4, M.sub.5, and M.sub.6 are the adjustment parameters, the value of the adjustment parameters ranges from 1 to 1; [0082] A.sub.3 is the non-linear asymmetric parameter of the roll contour profile curve of the work roll, and the value of A.sub.3 can be determined by formula (4):

A.sub.3=N.sub.1+N.sub.2.Math.Bp+N.sub.3.Math.Br+N.sub.4.Math.Br/Bp+N.sub.5/R.sup.3+N.sub.6.Math.Tq(4) [0083] wherein, [0084] Bp is the width of the rolled piece with the unit of meter; [0085] Br is the length of the roll body of the work roll with the unit of meter; [0086] R is the nominal radius of the work roll with the unit of meter, [0087] Tq is the on-load average torque of the work roll with the unit of KN.Math.m; [0088] N.sub.1, N.sub.2, N.sub.3, N.sub.4, N.sub.5, and N.sub.6 are the adjustment parameters, the value of the adjustment parameters ranges from 1 to 1; [0089] (2) Similarly, the upper profile curve of the lower work roll with respect to the center line of the roll is described by formula (5) as follows:

S.sub.WD(x)=B.sub.3.Math.x.sup.3B.sub.2.Math.x.sup.2B.sub.1.Math.x+B.sub.0(5) [0090] wherein, the conditions of B.sub.3, B.sub.2, B.sub.1, B.sub.0 are the same as described above.

[0091] (3) With the upper work roll and the lower work roll of the rolling mill mounted on the corresponding positions of the same rolling mill, the formula (6) of the no-load roll gap height curve between the upper work roll and the lower work roll is obtained and described as follows:

Gap(x)=(A.sub.3B.sub.3).Math.x.sup.3+(A.sub.2B.sub.2).Math.x.sup.2+(A.sub.1B.sub.1).Math.x+Gap.sub.0(6) [0092] wherein, [0093] x is the coordinate of the roll body of the work roll in the axial direction with the center of the roll body as the origin of the coordinate system; [0094] Gap.sub.0 is a set value of a roll gap with the center of the roll body as the origin of the coordinate system.

[0095] The benefits of the present invention as described above can be achieved using the rolling mill assembled by the above-mentioned work rolls to produce the plate/strip under the corresponding conditions.

[0096] As shown in FIG. 2, the no-load roll gap height curve 5 includes a linearly asymmetric portion and an asymmetric portion having a non-linear curve. The linearly asymmetric portion is formed between straight line 3 which indicates the maximum value of the roll gap and line 4 which connects the maximum value and minimum value of the no-load roll gap. The asymmetric portion having a non-linear curve is formed between line 4 which connects the maximum value and the minimum value of the roll gap and the no-load roll gap height curve 5. Moreover, the linearly asymmetric portion can be achieved by the work roll grinding. The linearly asymmetric portion can also be achieved by a method of single-sided screw-down adjustment during the rolling process, or be achieved by the asymmetric screw-down on both sides of the rolling mill.

[0097] Moreover, the non-linear asymmetric portion is compensated using the work roll grinding asymmetric curve and under the above-mentioned conditions of the present invention.

[0098] When the two work rolls of the rolling mill are grinded with the asymmetric curves, the degree of asymmetry between the upper work roll and the lower work roll can be undifferentiated or differentiated. One of the work rolls of the rolling mill can be grinded with the asymmetric curve to achieve the asymmetry of the overall roll gap between the upper work roll and the lower work roll without difference.

[0099] The compensation method for asymmetric plate profile of the plate/strip rolling mill of the present invention can be applied independently on the rolling mill or superposed with the roll thermal convexity compensation curve and the continuously variable convexity curve (with the Chinese patent application number 200980151893.7) to produce a new rolling mill non-linear work roll no-load profile curve to be applied to the rolling mill. However, no matter how the superposition is carried out, the characteristic of non-linear asymmetry of the no-load roll gap height curve between the upper work roll and the lower work roll of the rolling mill would not be changed.