Cast Strand Shear Upsetting for Reliable Rolling Grip
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Solution Overview
Problem
In thin slab cast-rolling plants, achieving the necessary gripping condition for continuous rolling is complex and expensive due to variable friction properties, often requiring manual intervention and costly upgrades, especially during the first pass where significant thickness reduction occurs, leading to production interruptions and suboptimal hot strip dimensions.
Innovation Solution
The method involves feeding a solidified cast strand or intermediate strip through shears with adjustable blades that perform a relative movement and an upsetting process to create a wedge-shaped contour, increasing friction for subsequent rolling by compressing or embossing the strip, allowing for improved thickness reduction and easier gripping during hot rolling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If larger work roller diameters are provided to meet gripping requirements, then gripping reliability is improved, but drive torque requirements and system cost increase
Solution Approach 1:
The method applies preliminary action by creating a compressed contour at the beginning of the casting strand before it enters the rolling mill. This pre-compression increases the friction coefficient at the entry point, ensuring that gripping requirements are met from the start without needing larger rollers or increased drive torque throughout the entire rolling process.
2Reliability
If additional rolling measures are implemented to meet gripping requirements, then gripping reliability is improved, but production continuity deteriorates
Solution Approach 1:
The compressed contour is created in advance during the casting process itself, before the strand enters the rolling mill. This preliminary action ensures that gripping requirements are already satisfied, eliminating the need for additional rolling measures or manual interventions that would interrupt production continuity.
3Reliability
If a different pass schedule with less material removal is used, then gripping requirements are met, but hot strip thickness specifications cannot be achieved
Solution Approach 1:
The invention applies local quality by creating compression only at the beginning portion of the casting strand where gripping is critical, while leaving the rest of the strand unchanged. This localized compression increases friction where needed without affecting the overall material removal schedule or the final hot strip thickness specifications.
4Ease of manufacture
If the casting strand is cut to length using conventional methods, then cutting is achieved, but liquid metal leakage occurs
Solution Approach 1:
The method performs preliminary action by creating a compressed contour at the beginning of the casting strand before cutting occurs. This pre-compression seals the still-molten core, preventing liquid metal from leaking out during the cutting process while still allowing the cut to be made.
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
This approach enhances operational reliability, reduces production interruptions, and allows for lighter, less expensive hot rolling mill designs by ensuring better fulfillment of the gripping condition, increasing production output and facility utilization.
Implementation Method 1
Upsetting a wedge-shaped contour to the beginning of the casting strand or intermediate strip located in the conveying direction in front of the shear by pressing an upsetting tool or an upsetting and embossing tool onto both surfaces of the casting strand or intermediate strip, so that the thickness of the beginning of the casting strand or intermediate strip is reduced
Implementation Method 2
performing a cut by executing a relative movement of the two shear blades
Implementation Method 3
the (Coulomb) coefficient of friction must be greater than or equal to the square root of the ratio of the thickness reduction to the radius of the rolls in the rolling mill
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
The invention relates to a method for cutting a cast strand or intermediate strip (1) using shears (2). In order to facilitate improved rolling of the section having significantly reduced thickness, the method according to the invention has the following steps: a) bringing part of the completely solidified cast strand or intermediate strip (1) in the conveying direction (F) of the cast strand or intermediate strip (1) in front of the shears (2); b) placing a first blade (3) of the shears (2) onto the one surface (4) of the cast strand or intermediate strip (1) and placing a second blade (5) of the shears (2) onto the other surface (6) of the cast strand or intermediate strip (1) and performing a cut by carrying out a relative movement of the two blades (3, 5), wherein at least one of the blades (3) is in a pushed forward position; c) upset forging or upset forging with stamping a wedge-shaped contour on the end of the cast strand or intermediate strip (1) that is in front of the shears (2) in the conveying direction (F), by pressing an upsetting tool or an upsetting and stamping tool (7, 5) onto both surfaces (4, 6) of the cast strand or intermediate strip (1) such that the thickness (d) of the start of the cast strand or intermediate strip (1) is reduced compared to the thickness (D) of the cast strand or intermediate strip (1), part of the upsetting tool or upsetting and stamping tool (5) being formed by one of the blades.