Oriented Electrical Steel Laser Grooving With Reflected-Heat Cooling

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Solution Overview

Problem

Existing methods for refining magnetic domains in grain-oriented electrical steel plates are inefficient, as they either lose refinement after annealing, are environmentally harmful, or have stability and complexity issues, and there is a need for improved processing to reduce iron loss and enhance magnetic flux density while maintaining high-speed processing capabilities.

Innovation Solution

A method and device that adjust the position of the steel plate support rolls, irradiate a laser beam to form a groove on the steel plate while controlling radiant heat reflection, and maintain an optimal operation environment, including cooling and tension control, to prevent optical system damage and effectively remove pollutants like hill up and spatter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a laser beam is irradiated to form a melting groove for permanent magnetic domain refinement, then iron loss reduction is achieved, but radiant heat reflection may damage the optical system

Engineering Contradiction:
Improveiron lossVSAvoidoptical system reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent converts the harmful radiant heat reflection into a beneficial effect by positioning a water-cooled roll to receive the reflected laser beam. The reflected beam, which would otherwise damage the optical system, is now used to cool the steel plate surface, enhancing the magnetic domain refinement effect while protecting the optical components.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The water-cooled roll acts as an intermediary between the reflected laser beam and the optical system. It intercepts the reflected radiant heat and transfers it to the cooling water, preventing damage to the optical system while maintaining the magnetic domain refinement process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If high-speed laser processing is used for magnetic domain refinement, then productivity is improved, but control of the process becomes more difficult

Engineering Contradiction:
Improveprocessing speedVSAvoidgroove formation control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements feedback control by monitoring the reflected laser beam characteristics and adjusting the water-cooled roll position and cooling water flow rate accordingly. This ensures stable groove formation and consistent magnetic domain refinement even at high processing speeds.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent optimizes processing parameters including laser power, scanning speed, and water flow rate to achieve high-speed processing while maintaining groove formation quality. By carefully controlling these parameters, the system achieves both high productivity and manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the laser beam is used for magnetic domain refinement, then magnetic flux density is enhanced, but hill up and spatter are generated as pollutants

Engineering Contradiction:
Improvemagnetic flux densityVSAvoidhill up and spatter
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful spatter and hill up by using the water-cooled roll to suppress them. The reflected laser beam on the water-cooled roll creates a cooling effect that prevents excessive melting and spatter formation, while the water flow helps flush away any generated pollutants.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent uses hydraulic cooling (water flow through the water-cooled roll) to control the melting and solidification process. The water flow not only cools the surface but also helps remove spatter and prevent hill up formation, reducing pollutants while maintaining magnetic flux density enhancement.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 stabilizes magnetic domain refinement at high speeds, ensuring a 5% or greater improvement in iron loss reduction before and after heat treatment, prevents optical system damage, and enhances the efficiency and workability of the process, producing high-quality products with optimized magnetic domain refinement.

Implementation Method 1

irradiating a laser beam to a surface of the steel plate to melt the steel plate and form a groove in the surface of the steel plate

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

absorbing and removing radiant heat due to reflection of the laser beam irradiated to the surface of the steel plate... heat-exchanging and absorbing radiant heat of a laser beam through a cooling block

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

circulating a coolant in the cooling block to maintain cooling temperature of the cooling block

Methodology Applied
Scientific EffectConvection cooling: Convection

Data Source

PatentEP3406742B9Method and device for magnetic domain refinement of oriented electrical steel plate
Publication Date: 2021.07.28 POHANG IRON & STEEL CO LTD
  • EP3406742B9 patent drawingFigure 1
  • EP3406742B9 patent drawingFigure 2~3
  • EP3406742B9 patent drawingFigure 4

AI summary

To optimize equipment and processes to enhance magnetic domain refinement efficiency and to enhance workability to improve processing capability, a method of refining a magnetic domain of a grain-oriented electrical steel plate includes zigzag controlling for transferring the steel plate without being inclined in right and left directions along a production line center, steel plate support roll position adjusting for controlling a position of the steel plate in up and down directions while supporting the steel plate, laser beam irradiating for irradiating a laser beam to a surface of the steel plate to melt the steel plate to form a groove in the surface of the steel plate, and removing for absorbing and removing radiant heat due to reflection of the laser beam irradiated to the surface of the steel plate during the laser beam irradiating.