Continuous Casting Rolling Reduction After-Cast Speed Control

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Solution Overview

Problem

In continuous casting, the quality of cast pieces deteriorates after casting completion due to center segregation and internal cracking, as existing methods fail to set appropriate rolling reduction conditions during this period.

Innovation Solution

A steel continuous casting method that involves changing the rolling reduction gradient in segments after casting completion, with specific speed control phases (deceleration, head solidification, and acceleration) to maintain a rolling reduction speed within a predetermined range, expressed by certain inequalities involving casting speed and rolling reduction gradient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a conventional water-cooled copper nozzle is used, then cooling efficiency is high, but the nozzle undergoes severe thermal stress and frequent clogging occurs

Engineering Contradiction:
Improvenozzle temperature controlVSAvoidnozzle service life and clogging resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the material parameter of the nozzle from conventional water-cooled copper to sintered porous metal material, which fundamentally alters the thermal and mechanical properties. This material transformation enables the nozzle to withstand thermal stress without cracking and prevents clogging while maintaining cooling efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes sintered porous metal material with controlled porosity (30-70%) to create a nozzle structure that combines cooling channels with porous surface. The porous structure prevents clogging by allowing uniform steel flow while internal water channels provide efficient cooling, resolving the contradiction between cooling performance and clogging resistance

Inventive Principle:
Principle #31Porous materials

2Productivity

If high-alloy steel is continuously cast, then production efficiency increases, but non-metallic inclusions and internal defects increase

Engineering Contradiction:
Improvecontinuous casting efficiencyVSAvoidsteel quality and defect reduction
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces a water-cooled porous metal nozzle as an intermediary device between the tundish and mold. This nozzle acts as a mediator that distributes steel flow uniformly, suppresses turbulence, and prevents non-metallic inclusions from entering the mold, thereby improving steel quality while maintaining continuous casting efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the conventional mechanical spray nozzle system with a water-cooled porous metal nozzle that utilizes capillary action and pressure differential for steel distribution. This substitution eliminates the mechanical complexity and clogging issues of traditional nozzles while achieving better flow control and reduced inclusions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If conventional spray nozzles are used for tundish cooling, then cooling is provided, but clogging frequently occurs and replacement is required

Engineering Contradiction:
Improvetundish temperature controlVSAvoidproduction continuity
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The water-cooled porous metal nozzle is designed with self-cleaning capability through its porous structure and water cooling system. The continuous water flow through internal channels prevents steel deposition and clogging, enabling the nozzle to maintain functionality without frequent replacement, thus improving production continuity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent employs composite structure combining porous metal matrix with internal water cooling channels. This composite design integrates cooling function and clogging resistance in a single component, eliminating the need for separate spray nozzles and cooling systems, and ensuring continuous operation without frequent maintenance

Inventive Principle:
Principle #40Composite materials

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 method improves the quality of cast pieces by preventing center segregation and internal cracking, allowing for efficient production of steel products with varied specifications.

Implementation Method 1

water-cooled porous metal nozzle

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

water-cooled porous metal nozzle

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

non-metallic inclusions can be suppressed

Methodology Applied
Scientific EffectPhysical separation: Filter (physical)

Data Source

PatentEP4527521A1Steel continuous casting method
Publication Date: 2025.03.26 JFE STEEL CORP
  • EP4527521A1 patent drawingFigure 1
  • EP4527521A1 patent drawingFigure 2~3
  • EP4527521A1 patent drawingFigure 4~5

AI summary

Provided is a steel continuous casting method capable of improving the quality of a cast piece cast in the period after the casting completion. A steel continuous casting method of performing continuous casting while a cast piece (3) is subjected to rolling reduction includes subjecting a cast piece (3) being continuously cast to rolling reduction and, after the casting completion, changing a rolling reduction gradient in a segment (14) of applying the rolling reduction, to control a rolling reduction speed within a predetermined range.