Strip flatness prediction method considering lateral spread during rolling

Patent metadata

Field	Value
Publication number	US-11745236-B2
Application number	US-202017112389-A
Country	US
Kind code	B2
Filing date	Dec 4, 2020
Priority date	Dec 6, 2019
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

The present disclosure provides a strip flatness prediction method considering lateral spread during rolling. The method includes: step 1: acquiring strip parameters, roll parameters and rolling process parameters; step 2: introducing a change factor of a lateral thickness difference before and after rolling and a lateral spread factor by considering lateral metal flow, and constructing a strip flatness prediction model based on the coupling of flatness, crown and lateral spread; step 3: constructing a three-dimensional (3D) finite element model (FEM) of a rolling mill and a strip, simulating strip rolling by the 3D FEM, extracting lateral displacement and thickness data of the strip during a stable rolling stage, calculating parameters of the strip flatness prediction model based on the coupling of flatness, crown and lateral spread; and step 4: predicting the flatness of the strip by the strip flatness prediction model based on the coupling of flatness, crown and lateral spread.

First claim

What is claimed is:

1. A strip flatness prediction method considering lateral spread during rolling, comprising the following steps:
step 1: acquiring strip parameters, roll parameters and rolling process parameters, wherein the strip parameters comprise strip width, thickness, crown ratio, density, elastic modulus, yield strength, Poisson's ratio and tangent modulus; the roll parameters comprise diameter, barrel length, density, elastic modulus and Poisson's ratio of a work roll; the rolling process parameters comprise friction and rolling speed;
step 2: constructing a strip flatness prediction model based on coupling of flatness, crown and lateral spread by considering lateral metal flow;
step 3: constructing a three-dimensional (3D) finite element model (FEM) of a rolling mill and a strip according to the strip parameters, the roll parameters and the rolling process parameters, simulating strip rolling by the 3D FEM, extracting lateral displacement and thickness data of the strip during a stable rolling stage, and calculating parameters of the strip flatness prediction model based on the coupling of flatness, crown and lateral spread; and
step 4: predicting the flatness of the strip by the strip flatness prediction model based on the coupling of flatness, crown and lateral spread,
wherein step 2 comprises the following steps:
step 2.1: constructing a coordinate system for the strip by taking a center of the strip as an origin of coordinates and width, length and thickness directions as 3D coordinate axes; regarding the strip before rolling as an entity of continuous longitudinal fiber strips; taking a longitudinal fiber strip at a widthwise position with a distance y from a center of the strip, and defining width, thickness and length of the longitudinal fiber strip before rolling as dy, H(y) and L(y) respectively; increasing the width of the longitudinal fiber strip after rolling to dy+[u(y+dy)−u(y)], reducing the thickness of the longitudinal fiber strip after rolling to h(y), and increasing the length of the longitudinal fiber strip after rolling to l(y), by considering lateral flow of metal particles during the strip rolling, wherein u(y) represents a lateral displacement function of metal particles of the strip;
step 2.2: constructing the strip flatness prediction model based on the coupling of flatness, crown and lateral spread:
step 2.2.1: according to a principle of constant volume before and after rolling:
h ( y )· l ( y )·[ dy+u ( y+dy )− u ( y )]= H ( y )· L ( y )· dy   (1)

deriving the length of the longitudinal fiber strip after rolling as:

l
⁡
(
y
)

=

H
⁡
(
y
)

·

L
⁡
(
y
)

·
dy

h
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(
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·

[

dy
+

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(

y
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d
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y

)

-

u
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)

]

=

H
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(
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L
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(
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h
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[

1
+

u
′

(
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(
2
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where u′(y) represents a derivative function of the lateral displacement function u(y);
step 2.2.2: determining a reference length for all longitudinal fiber strips of the strip after rolling;

l
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(

y
¯

)

=

Assignees

• Univ Northeastern

Inventors

• Sun Jie
• Wang Qinglong
• Shan Pengfei
• Wei Zhen
• Peng Wen
• Ding Jingguo
• Zhang Dianhua

Classifications

• B21B37/28 Primary

  Control of flatness or profile during rolling of strip, sheets or plates · CPC title

• G06F30/23

  using finite element methods [FEM] or finite difference methods [FDM] · CPC title

• G06F30/25

  using particle-based methods · CPC title

• G06F30/367

  Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods · CPC title

• G06F30/398

  Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36) · CPC title