Upsetting Stand Roll Control for Shorter Width Transition Sections
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Solution Overview
Problem
The length of the transition section in continuous casting and rolling mills, where the width of the metal strand changes from an initial to a final width, is excessively long, leading to scrap formation, especially when using a continuous casting machine, and installing a compression stand does not fully resolve this issue.
Innovation Solution
An operating method that involves using a control unit to position and adjust work rolls in an upsetting stand upstream of the rolling stands, determining initial and final positions and a travel curve based on static and dynamic properties of the metal strand, to compress the transition section effectively, thereby reducing its length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the width of the continuous casting machine is changed during the casting process, then the width of the metal strand is adjusted from initial width to final width, but the transition section becomes excessively long (several meters) leading to scrap formation
Solution Approach 1:
The transition section is divided into multiple zones along the rolling direction, with each zone having a specific function (compression, width adjustment, stabilization). This segmentation allows precise control of width changes and reduces the overall length of the transition section by concentrating the width change in a controlled manner rather than allowing gradual change over several meters
Solution Approach 2:
The compression stand performs preliminary width adjustment and compression of the transition section before the metal strand enters the main rolling stands. By pre-adjusting the width and compressing the transition section in advance, the subsequent rolling process receives a more uniform strand, reducing the length of the transition section and minimizing scrap
2Speed
If a compression stand is installed to change width more quickly, then the transition section length is reduced, but a significant section still remains that has neither initial nor final width
Solution Approach 1:
The compression stand applies localized compression and width adjustment specifically to the transition section, creating a zone with controlled width change. By concentrating the width adjustment action in a specific local area rather than distributing it over a long section, the transition section length is significantly reduced while achieving the required width change from initial to final width
Solution Approach 2:
The compression stand changes physical parameters (compression force, roll gap, rolling speed) to rapidly adjust the width of the transition section. By modifying these parameters in a controlled sequence, the width changes from initial to final width over a shorter distance, reducing the transition section length while maintaining quality
3Manufacturing precision
If work rolls are positioned against the transition section to compress it, then the transition section length is reduced, but precise control of the width change requires complex positioning and travel curve adjustment
Solution Approach 1:
The control system continuously monitors the width of the metal strand during the compression and rolling process, comparing it with the target width profile. Based on this feedback, the control system automatically adjusts the position of work rolls and the travel curve to maintain precise width control, reducing the need for overly complex manual positioning while achieving high manufacturing precision
Solution Approach 2:
The work rolls and control system dynamically adjust the compression force and roll position based on real-time conditions of the metal strand. The travel curve is dynamically optimized to match the actual width change requirements, allowing precise width control while adapting to variations in material properties and process conditions, thereby reducing unnecessary system 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 significantly reduces the length of the transition section, ensuring the width of the flat rolled stock closely matches the target width, minimizing scrap and optimizing the rolling process.
Implementation Method 1
work rolls of the compression stand are positioned against the transition section during the passage of the transition section through the compression stand, so that the cast metal strand is compressed in the transition section
Implementation Method 2
the work rolls of the compression stand are set to an initial position by a control device that controls at least the compression stand at the beginning of the passage of the transition section through the compression stand, are gradually set to a final position according to a travel curve
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
In a continuous casting machine (1), a metal strand (2) is cast and, without prior division into sections, is rolled from the casting heat into a flat rolled stock in the rolling stands (4) downstream of the continuous casting machine (1). During the casting of the metal strand (2), a width (b0) of the metal strand (2) is changed by the continuous casting machine (1) from an initial width to a final width, so that the metal strand (2) has a corresponding transition section. Before the transition section is rolled in the rolling stands (4), work rolls of the upsetting stand (3) are engaged against the transition section in an upsetting stand (3) located upstream of the rolling stands (4) during the transition section's passage through the upsetting stand (3), so that the metal strand (2) is upset in the transition section.The work rolls are set to an initial position by a control unit (6) at the beginning of the passage through the transition section of the upsetting stand (3) and gradually adjusted to a final position according to a travel curve during the passage through the transition section of the upsetting stand (3). At the end of the passage through the transition section of the upsetting stand (3), they are moved away from the metal strand (2). If the initial width is greater than the final width, the final position corresponds to the final width, and the control unit (6) determines the initial position and the travel curve online using a model (12) as a function of the aforementioned static and dynamic properties, so that the width of the flat rolled material in the area of the transition section (5) corresponds as closely as possible to the target width of the flat rolled material after the transition section.If the initial width is smaller than the final width, the initial position corresponds to the initial width and the control device (6) determines the final position and the travel curve online using the model (12) as a function of the aforementioned static and dynamic properties, so that the width of the flat rolled material in the area of the transition section corresponds as closely as possible to a target width of the flat rolled material before the transition section.