Continuous Casting Slab End Shaping for Lower Hot-Roll Crop Loss

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Solution Overview

Problem

The asymmetrical deformation of the head and tail of continuous-casting slabs during hot rolling leads to irregular shapes, resulting in significant yield loss due to unnecessary cutting, which affects production efficiency and material utilization in hot rolling lines.

Innovation Solution

A method of pre-controlling the shapes of continuous-casting slab head and tail by inverse compensation, where the head surface concaves inward and the tail surface projects outward, reducing the length of irregular parts and optimizing cutting, achieved through modifications to cutting devices and specific cutting techniques such as curve, straight and arc, and broken line methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional straight-line cutting method is used for continuous-casting slabs, then the cutting process is simple and fast, but the head and tail of the intermediate slab develop irregular shapes after rough rolling, causing significant yield loss

Engineering Contradiction:
Improveyield loss from head and tail cuttingVSAvoidcutting device complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The cutting device performs preliminary shaping of the slab head and tail ends before rough rolling. By pre-forming the head and tail surfaces with specific curvature radii (R1≥50mm, R2≥50mm) and controlling the transition zone geometry, the slab enters the rough rolling process with optimized geometry, preventing the development of irregular fishhead and dovetail shapes that would otherwise require extensive cutting removal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of cutting away irregular shapes after rough rolling, the invention inverts the approach by pre-shaping the head and tail ends before rolling. The cutting device creates convex or concave surfaces with controlled radii that compensate for the asymmetric deformation expected during rough rolling, thereby eliminating the need for subsequent removal of irregularities.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If the cutting device is modified to implement pre-control shaping, then the yield loss is reduced, but the device complexity and operation difficulty increase

Engineering Contradiction:
Improveproduction efficiencyVSAvoidcutting operation difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The cutting device incorporates adjustable parameters including cutting depth (h1, h2), cutting width (b1, b2), and curvature radius (R1, R2≥50mm). These parameters can be modified based on slab dimensions and rolling process requirements, allowing optimization of the pre-shaping process without requiring complete device redesign. The programmable control system enables flexible adjustment of cutting paths and dimensions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

A programmable control system serves as an intermediary between the operator and the complex cutting device. The control system coordinates the motion of cutting tools, manages the sequencing of cutting passes, and ensures precise geometry formation. This intermediary layer simplifies operation by automating the complex multi-stage cutting process while maintaining the ability to achieve the required geometric precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2818259B1Pre-control method of head and tail shapes of continuous casting slab for reducing the removed amount from the head and tail of hot-rolled intermediate slab
Publication Date: 2022.11.30 BAOSHAN IRON & STEEL CO LTD
  • EP2818259B1 patent drawingFigure 1
  • EP2818259B1 patent drawingFigure 2
  • EP2818259B1 patent drawingFigure 3~4

AI summary

The present invention relates to a method of pre-controlling the shapes of continuous-casting slab head and tail. A method of pre-controlling the shapes of continuous-casting slab head and tail for reducing the cut amount of the head and tail of the hot rolling intermediate slab, adopts the way of pre-controlling to cut the continuous-casting slab head and tail, that is, cutting the slab into the shape-the end surface of its head concaving inwards and that of its tail projecting outwards. The head and tail of a slab is cut in a curve which is symmetric to the center line in width thereof; the arc height, i.e. the maximum value of the concave amount at the head or that of the projection amount at the tail is controlled within 0mm∼50mm. The present invention can substantially decrease the length of the uneven deforming parts at the head and tail of the intermediate slab, thereby reducing the cut amount thereof.