Steel Strip Continuous Casting Temperature Profile Control

Solution Overview

Problem

The existing steel strip manufacturing processes using thin slab technologies face challenges in reducing investment and production costs, particularly due to the need for long tunnel furnaces to achieve temperature uniformity, which limits casting speeds and productivity.

Innovation Solution

A process and plant design that maintains a non-uniform temperature profile with the core being higher than the surface, allowing for reduced furnace length and increased casting speeds, achieved by using a shorter tunnel furnace or induction furnace to maintain a triangular temperature trend, resulting in lower rolling pressure and energy savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a long tunnel furnace is used to homogenize temperature throughout the slab cross-section, then temperature uniformity is improved, but furnace length and residence time increase, reducing productivity and increasing investment costs

Engineering Contradiction:

Improvetemperature uniformityVSAvoidcasting speed

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies local quality by maintaining different temperature levels in different regions of the slab - specifically, the core region is kept at a higher temperature than the surface regions. This non-uniform temperature distribution is intentionally created and maintained through controlled cooling rates during continuous casting, allowing the core to remain sufficiently hot for rolling while surfaces cool appropriately. This resolves the contradiction by eliminating the need for long residence times to achieve uniformity, thereby increasing productivity without sacrificing temperature control.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent inverts the conventional approach by deliberately maintaining a non-uniform temperature profile (core hotter than surfaces) rather than attempting to achieve uniform temperature distribution. This inversion of the traditional temperature homogenization goal allows for much shorter furnace lengths and residence times, directly resolving the contradiction between temperature control and productivity.

Inventive Principle:

Principle #13The other way round (Inversion)

2Stability of the object's composition

If a long tunnel furnace is used to achieve temperature uniformity, then temperature homogeneity is improved, but plant space and investment costs increase

Engineering Contradiction:

Improvetemperature homogeneityVSAvoidfurnace length

Core Design Contradiction:

Stability of the object's compositionVSLength of stationary object

Solution Approach 1:

The patent applies local quality by maintaining different temperature levels in different regions of the slab - specifically, the core region is kept at a higher temperature than the surface regions. This non-uniform temperature distribution is intentionally created and maintained through controlled cooling rates during continuous casting, allowing the core to remain sufficiently hot for rolling while surfaces cool appropriately. This resolves the contradiction by eliminating the need for long residence times to achieve uniformity, thereby increasing productivity without sacrificing temperature control.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent inverts the conventional approach by deliberately maintaining a non-uniform temperature profile (core hotter than surfaces) rather than attempting to achieve uniform temperature distribution. This inversion of the traditional temperature homogenization goal allows for much shorter furnace lengths and residence times, directly resolving the contradiction between temperature control and productivity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If casting speed is increased to improve productivity, then productivity is improved, but temperature uniformity deteriorates without a proportionally longer furnace

Engineering Contradiction:

Improvecasting speedVSAvoidtemperature uniformity

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by maintaining different temperature levels in different regions of the slab - specifically, the core region is kept at a higher temperature than the surface regions. This non-uniform temperature distribution is intentionally created and maintained through controlled cooling rates during continuous casting, allowing the core to remain sufficiently hot for rolling while surfaces cool appropriately. This resolves the contradiction by eliminating the need for long residence times to achieve uniformity, thereby increasing productivity without sacrificing temperature control.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent inverts the conventional approach by deliberately maintaining a non-uniform temperature profile (core hotter than surfaces) rather than attempting to achieve uniform temperature distribution. This inversion of the traditional temperature homogenization goal allows for much shorter furnace lengths and residence times, directly resolving the contradiction between temperature control and productivity.

Inventive Principle:

Principle #13The other way round (Inversion)

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 enables higher productivity and energy savings by allowing higher casting speeds with reduced plant space and investment, while maintaining product quality through controlled temperature profiles and mass flow rates.

Implementation Method 1

a first type which does not provide for solution of continuity between the continuous casting step and the rolling one, a second type wherein said two steps are separated, thereby with a solution of continuity providing for the use of a Steckel rolling mill, and finally a third type, again with solution of continuity

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

A process and plant design that maintains a non-uniform temperature profile with the core being higher than the surface, allowing for reduced furnace length and increased casting speeds, achieved by using a shorter tunnel furnace or induction furnace

Methodology Applied

Scientific EffectElectromagnetic induction heating: Electromagnetic Induction

Data Source

PatentUS8025092B2Process and related plant for producing steel strips with solution of continuity

Publication Date: 2011.09.27 ARVEDI GIOVANNI

AI summary

A process for the manufacturing of steel strips with solution of continuity is described, comprising a continuous casting step for thin stabs with a high “mass flow”, a shearing step and subsequent heating in furnace, followed by a multiple stand rolling step, wherein the average temperature of the product at the inlet of the rolling is higher than the surface temperature, which is equal to at least 1100° C., lower than that measured in the inner central area by about 100° C. A plant is also described for the accomplishment of such process, wherein at the inlet of a furnace (25; 35), possibly of the induction type, combined with a temperature maintaining tunnel (36) a shear (3) is provided for, cutting into pieces (24; 34) a slab (22; 32) coming from continuous casting (21; 31), wherein the distance between the outlet of said continuous casting and the inlet into the finishing rolling mill (29; 39) is not greater than 100 m.