Temper Rolling Control for W-Shaped Metal Strip Warp
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Solution Overview
Problem
Existing methods struggle to effectively control warped shapes with W-shaped cross-sections and higher-order functions in high-strength steel sheets during temper rolling, leading to insufficient shape correction despite the use of temper rolling mills.
Innovation Solution
A metal-strip warped-shape control method using approximation curves calculated from entry-side and exit-side measurements, combined with a warped-shape prediction model, to set operating parameters for the temper rolling mill, reducing warp height by adjusting the bending force of work rolls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cooling rate of the metal strip is increased to improve press formability, then the mechanical properties are improved, but the shape of the metal strip becomes easily changeable due to thermal contraction and phase transformation
Solution Approach 1:
The patent applies preliminary shaping action by introducing a shaping roll section upstream of the temper rolling mill. This shaping section pre-corrects the warped shape of the metal strip before it enters the temper rolling mill, allowing the subsequent temper rolling to achieve better final flatness. The shaping rolls apply differential forces to counteract the thermal contraction and phase transformation effects that occur during rapid cooling, thereby maintaining shape stability while preserving the improved mechanical properties.
2Shape
If shape correction is performed using a temper rolling mill, then the shape of the metal strip is improved, but when the yield stress is large, it is difficult to sufficiently flatten the metal strip
Solution Approach 1:
The patent introduces a shaping roll section that performs preliminary shape correction on the metal strip before it enters the temper rolling mill. This pre-shaping reduces the magnitude of warped shapes, making the subsequent temper rolling more effective. By reducing the initial warp height through the shaping section, the temper rolling mill can achieve sufficient flattening even when the metal strip has high yield stress that would otherwise resist the flattening action.
Solution Approach 2:
The shaping roll section applies localized differential forces to different regions of the metal strip width. The shaping rolls are configured to apply greater force to regions with higher warp heights, creating a non-uniform pressure distribution that precisely targets the warped areas. This local quality approach allows effective shape correction without requiring excessive overall rolling force, making it feasible to flatten high-yield-stress metal strips.
3Ease of manufacture
If conventional temper rolling is used without considering entry-side warped shape, then the process is simple, but the warp height remains high after temper rolling
Solution Approach 1:
The patent adds a relatively simple shaping roll section upstream of the existing temper rolling mill. This shaping section measures the entry-side warped shape and applies preliminary correction before the metal strip enters the temper rolling mill. The addition of this preliminary shaping stage, while increasing process complexity slightly, dramatically improves the final flatness outcome by reducing the warp height that the temper rolling mill must correct.
Solution Approach 2:
The patent implements a feedback control system where the entry-side warped shape is measured, and this measurement is used to control the shaping rolls. The shaping roll positions and forces are adjusted based on the measured warp distribution, creating a closed-loop control system. This feedback mechanism ensures that the preliminary shaping action is optimized for the actual entry-side shape conditions, achieving better flatness outcomes while maintaining reasonable process complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enables precise control of warped shapes with W-shaped cross-sections and higher-order functions, resulting in reduced warp height and improved shape consistency of high-strength steel sheets.
Implementation Method 1
a warped-shape measurement device that measures a warped shape of the metal strip
Implementation Method 2
a temper rolling mill that corrects a shape of a metal strip continuously conveyed
Implementation Method 3
a cooling zone for cooling the metal strip heated in the heating zone
Implementation Method 4
a heating zone for heating the metal strip
Data Source
AI summary
A metal-strip warped-shape control method for controlling an exit-side warped shape, which is a warped shape of a metal strip downstream of a temper rolling mill in a metal-strip manufacturing facility, the metal-strip manufacturing facility including the temper rolling mill that corrects a shape of the metal strip continuously conveyed, and a warped-shape measurement device that measures a warped shape of the metal strip, the metal-strip warped-shape control method including: calculating an approximation curve for the warped shape of the metal strip using an approximation method selected from parabolic approximation, circular arc approximation, and envelope approximation; and setting operating parameters of the temper rolling mill that can reduce a warp height of the exit-side warped shape based on the approximation curve that is calculated.