Assembled Slab Edge Geometry for Rolling Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The rolling of assembled metal slabs, particularly aluminium, results in non-uniform deformation leading to increased shearing and crop losses due to uneven clad thickness, which affects mill productivity and metal yield, especially in hot rolling processes.
Innovation Solution
A core slab with reduced cross-section in at least one longitudinal edge and a second slab assembled in parallel, where the core slab's edges are machined to form a cut-out or tapered shape to minimize deformation resistance and ensure even clad thickness during rolling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If slabs are rolled with standard geometry, then the rolling process can proceed, but non-uniform deformation occurs leading to increased shearing and crop losses
Solution Approach 1:
The slab edges are given a reduced cross-section geometry (cut-out or tapered shape) to create local variation in material distribution. This local geometric modification ensures more uniform deformation and clad thickness at the edges during rolling, directly addressing the non-uniform deformation problem that causes shearing and crop losses.
Solution Approach 2:
The slab edges are pre-formed with reduced cross-section geometry before the rolling process begins. This preliminary geometric preparation prevents non-uniform deformation and clad thickness variation from occurring during rolling, thereby reducing shearing and crop losses at the edges.
2Manufacturing precision
If slab edges are modified to reduce deformation resistance, then clad thickness uniformity improves, but additional machining steps are required
Solution Approach 1:
The reduced cross-section geometry is formed on the slab edges during the casting process itself, before the rolling operation. This preliminary formation eliminates the need for separate machining steps to create the geometric modification, thereby improving clad thickness uniformity without significantly increasing process complexity.
Solution Approach 2:
The cross-sectional dimensions of the slab edges are modified (reduced) to change the deformation characteristics. This parameter change in geometry is implemented either during casting or through minimal machining, enabling uniform clad thickness formation during rolling while keeping the additional process steps to a minimum.
3Reliability
If clad material is used to improve corrosion resistance, then product performance improves, but non-uniform deformation becomes more severe due to softer metal deforming more easily
Solution Approach 1:
The reduced cross-section geometry at the slab edges creates a local quality variation that compensates for the softer deformation characteristics of the clad material. This geometric modification ensures that the softer clad metal deforms more uniformly at the edges, preventing excessive thinning and maintaining clad thickness uniformity while preserving the corrosion resistance benefits.
Solution Approach 2:
The cross-sectional geometry parameter of the slab edges is modified to account for the different deformation behavior of the clad material. By reducing the edge cross-section, the deformation distribution is optimized for clad materials that deform more easily, ensuring uniform clad thickness while maintaining the corrosion protection provided by the clad layer.
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3
AI summary
The present invention relates to the rolling of assembled metal slabs and, more particularly, to methods for increasing slab rolling yields and rolling mill efficiency by minimizing shearing and crop losses in the rolling of assembled slabs. This invention provides an assembled structure for aluminium rolled products comprising a core slab (1) with a reduced cross-section in the thickness direction of the slab in at least one of the slab edges running parallel to the rolling direction. At least one second slab (2) is assembled to the core slab. The edges of the slab (1) may have a cut-out and/or a tapered shape. The invention also provides a method of reducing shearing and crop losses at the rolling of assembled slabs, by using a core slab (1) with a reduced cross-section in the thickness direction of the slab in at least one of the slab edges running parallel to the rolling direction.