EMAT Phased Array Probe for Continuous Casting Surface Defect Detection

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Solution Overview

Problem

Current continuous casting methods face challenges in real-time adaptation of process parameters to ensure high-quality metallurgical cast products due to limitations in surface defect detection, particularly low lateral resolution in optical methods and the need for mechanical movement in eddy current methods.

Innovation Solution

A continuous casting device equipped with an EMAT sensor designed as a phased array for non-contact ultrasonic testing, allowing for real-time detection and evaluation of surface defects, which adjusts process parameters like casting speed and cooling based on ultrasonic signal data, eliminating the need for mechanical movement and providing detailed defect analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If optical methods (CCD cameras) are used for surface quality checking, then real-time detection is achieved, but lateral resolution is low

Engineering Contradiction:
Improvereal-time detection speedVSAvoidlateral resolution
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent replaces optical detection methods with electromagnetic acoustic transducer (EMAT) technology, which uses electromagnetic fields to generate and detect acoustic waves in the metallurgical cast product. This substitution enables high-resolution defect detection without the lateral resolution limitations of optical systems, while maintaining real-time detection capability through non-contact measurement

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

Solution Approach 2:

The patent changes the detection parameter from optical reflection to acoustic wave propagation. By using EMAT sensors that generate ultrasonic waves and detect acoustic responses, the system achieves superior measurement precision for surface and near-surface defects compared to optical methods, while the automated scanning process maintains real-time detection speed

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If eddy current transducer is used for surface defect detection, then surface quality inspection is achieved, but the inspection device must be moved over the cast product

Engineering Contradiction:
Improvesurface defect detection capabilityVSAvoidmechanical movement requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanically moved eddy current transducer with a stationary EMAT sensor system. The EMAT sensors are fixed in position and use electromagnetic fields to inspect the cast product as it passes by, eliminating the need for mechanical movement while maintaining high detection precision for surface and near-surface defects

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

Solution Approach 2:

The EMAT sensor system performs multiple functions: it can detect surface defects, near-surface defects, and internal defects with a single stationary device. This multi-functional capability replaces the need for separate inspection devices and mechanical movement, simplifying the overall system while enhancing detection comprehensiveness

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If real-time detection and control is implemented, then process parameter adaptation is improved, but detection accuracy must be sufficient to guide control decisions

Engineering Contradiction:
Improveprocess parameter adaptationVSAvoiddefect detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent employs EMAT technology that uses electromagnetic acoustic transduction to achieve high-precision defect detection. The electromagnetic fields generated by the EMAT sensors interact with the metallurgical cast product to produce acoustic waves that reflect off defects, providing accurate real-time data for process control adaptation

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

Solution Approach 2:

The system implements real-time feedback control by continuously monitoring defect detection results and automatically adjusting process parameters such as casting speed and cooling rate. The high measurement precision of the EMAT sensors ensures that the feedback signals are accurate enough to guide control decisions and improve product quality

Inventive Principle:
Principle #23Feedback

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 solution enables more effective detection and correction of surface defects, reducing rejects and improving product quality by allowing for real-time adjustment of process parameters without mechanical complexity, ensuring consistent testing quality across varying temperatures.

Implementation Method 1

A detection device for detecting surface defects and/or defects close to the surface in the metallurgical cast products in the production line; the detection device is at least one EMAT (electromagnetic acoustic transducer) sensor designed as a phased array

Methodology Applied
Scientific EffectElectromagnetic acoustic transduction: Electromagnetic Induction

Implementation Method 2

the EMAT sensor is designed to receive ultrasonic signals which result from reflections of the ultrasonic wave front on the metallurgical cast products

Methodology Applied
Scientific EffectUltrasonic wave reflection: Reflection

Data Source

PatentEP2939017B1Continuous casting device with detecting device for detecting surface defects in cast metallurgical products, and method
Publication Date: 2017.05.24 SMS GROUP GMBH
  • EP2939017B1 patent drawingFigure 1~2

AI summary

The invention relates to a continuous casting device (1) and a continuous casting method for producing and/or inspecting cast metallurgical products (3). The continuous casting device (1) comprises a detecting device (5) for detecting surface defects and/or defects near the surface of the cast metallurgical products (3) in the production line. The detecting device (5) is at least one EMAT sensor (50) designed as an array-type probe.