Nonlinear Eddy Current Technique for Fatigue Detection and Classification in Martensitic Stainless-Steel Samples

Based on electromagnetic theory, metallurgical characteristics can be detected by eddy current nondestructive testing technology. In this study, the relationship between the surface microstructure and the eddy current output of martensitic stainless steel AISI 410 was studied using this technology at different quenching temperatures. The mechanical properties include material hardness, microstructure types and microstructural changes after thermal treatment was evaluated. Using Vickers hardness as the surface hardness index of AISI 410 steel, the relationship between eddy current output signal, in terms of impedance and inductance, and sample surface hardness was studied and the effects of different quenching temperatures on the steel’s surface hardness was examined. In addition, the change of microstructure types of AISI 410 steel after thermal treatment was detected by the eddy current nondestructive testing method, and the results were verified by metallographic microscopy.

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Saturated low frequency eddy current technique applied to microstructure phase quantification in duplex stainless steel

2013 Far East Forum on Nondestructive Evaluation/Testing: New Technology and Application ◽

10.1109/fendt.2013.6635518 ◽

2013 ◽

Cited By ~ 2

Author(s):

Joao M. A. Rebello ◽

Maria C. L. Areiza ◽

Cesar G. Camerini ◽

Joao V. Rocha

Keyword(s):

Stainless Steel ◽

Duplex Stainless Steel ◽

Eddy Current ◽

Low Frequency ◽

Current Technique ◽

Phase Quantification

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Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209306 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 47-55

Author(s):

Takuma Tomizawa ◽

Haicheng Song ◽

Noritaka Yusa

Keyword(s):

Stainless Steel ◽

Eddy Current ◽

Pressure Vessels ◽

Eddy Current Testing ◽

Probability Of Detection ◽

Current Testing ◽

Multiple Signal ◽

Signal Features ◽

Inner Surface ◽

Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

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