Steel Rolling Phase Detection Using Force-Temperature Gradients

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Solution Overview

Problem

Existing methods for determining the structural transformation from austenitic to ferritic structure during steel rolling are inaccurate due to modeling uncertainties, especially when cooling is involved, as temperature measurements are taken far from the rolling process and input variables like chemical composition are not precisely known.

Innovation Solution

The method involves determining the gradient of rolling force and moment relative to temperature during steel rolling, allowing for precise identification of phase transformations by measuring these forces and moments, and using this data to determine if a phase transformation from austenitic to ferritic structure occurs, without relying on thermo-kinetic models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If thermo-kinetic models are used to determine phase transformation, then the determination can be performed with available temperature measurements, but the accuracy is reduced due to modeling uncertainties and errors

Engineering Contradiction:
Improveaccuracy of phase transformation determinationVSAvoidcomplexity of measurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the thermo-kinetic modeling approach (software/calculation system) with a direct mechanical measurement approach using rolling force sensors. Instead of calculating phase transformation indirectly through temperature models, the invention directly detects it through rolling force gradient measurements, eliminating modeling uncertainties while maintaining system simplicity.

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

2Measurement precision

If temperature measurements are taken upstream of descaler or cooling unit, then the temperature data can be obtained for modeling, but the accuracy deteriorates due to time delays and model-based calculations

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidtime delay in temperature data
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the phase transformation detection function from the temperature measurement system. Instead of relying on temperature data that requires time delays for measurement and subsequent model-based calculations, the invention directly extracts phase transformation information from rolling force measurements taken at the rolling stand, eliminating both the time delay and the need for model-based temperature calculations.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of information

If model-based calculation of temperature is performed, then temperature values can be obtained for analysis, but errors accumulate the further the modeling progresses

Engineering Contradiction:
Improveinformation accuracy in temperature dataVSAvoidcomplexity of temperature modeling system
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent substitutes the complex temperature modeling system with a direct mechanical measurement system. By measuring rolling force gradients at the rolling stand, the invention directly detects phase transformation without needing to model temperature behavior, thereby eliminating information loss and errors that accumulate through multi-step modeling processes.

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

4Measurement precision

If input variables for modeling are not precisely known, then the modeling process can still proceed, but the determination accuracy is reduced

Engineering Contradiction:
Improveaccuracy of phase transformation determinationVSAvoidflexibility in handling unknown variables
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent makes the phase transformation detection system self-sufficient by using rolling force measurements that are already available during the rolling process. The method does not require external input variables such as chemical composition or precise temperature data - the rolling force gradient itself provides the necessary information, making the system adaptable to varying steel compositions without additional measurements or complex corrections.

Inventive Principle:
Principle #25Self-service

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 provides accurate determination of structural phases during rolling, allowing for adjustments in operating parameters to optimize energy consumption, productivity, and product properties by identifying the exact rolling passes where phase transformations occur, thus minimizing errors associated with modeling uncertainties.

Implementation Method 1

rolling of successively rolled sections of the strip in the rolling stand during a rolling pass

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

a detection device for the metrological detection of values which are characteristic of the rolling force occurring during rolling of the sections of the strip and/or the rolling torque occurring during rolling of the sections of the strip

Methodology Applied
Scientific EffectMetrological detection:

Implementation Method 3

on the basis of the gradient it is determined whether or not a phase transformation from an austenitic to a ferritic structure occurs in the sections of the strip during rolling in the rolling stand

Methodology Applied
Scientific EffectPhase transformation: Phase Change

Data Source

PatentEP4364867A1Rolling of steel with metrological detection of phase transformation
Publication Date: 2024.05.08 PRIMETALS TECH AUSTRIA GMBH
  • EP4364867A1 patent drawingFigure 1~2
  • EP4364867A1 patent drawingFigure 3
  • EP4364867A1 patent drawingFigure 4~5

AI summary

In a rolling stand (3) of a rolling mill (1), a steel strip (2) is rolled. During the rolling of successively rolled sections (10) of the strip (2), values ​​characteristic of the rolling force (FW) and/or the rolling torque (M) are measured. By utilizing the rolling forces (FW) and/or rolling torques (M) and changes (δT) in the corresponding temperatures (T) of the sections (10) of the strip (2), a gradient (G) of the rolling force (FW) and/or the rolling torque (M) relative to the temperature (T) is determined. Based on the gradient (G), it is determined whether a phase transformation from an austenitic to a ferritic microstructure occurs in the sections (10) of the strip (2) during rolling in the rolling stand (3).