The Paton Welding Journal, 2025, №10

2025 №10 (05)

DOI of Article 10.37434/tpwj2025.10.06

2025 №10 (01)

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The Paton Welding Journal, 2025, #10, 36-48 pages

Methodology of using standard specimens with defects for eddy current inspection: classification, typical examples, signals research and statistical method for parameters assessment

V.M. Uchanin

G.V. Karpenko Physico-Mechanical Institute of the NASU 5 Naukova Str., 79060, Lviv, Ukraine. E-mail: vuchanin@gmail.com

Abstract
The work was aimed at development of a methodology for using reference standards (RS) with defects to ensure high reliability and repeatability of eddy current flaw detection results. A classification of reference standards with defects is proposed and relevant examples are given to confirm the validity of the proposed classification. As an example, designs of composite multi-valued reference standards are presented for simulating surface and subsurface defects in cylindrical and flat objects under eddy current testing. New designs of composite reference standards are shown that simulate defects with different depths of occurrence. A corresponding set of RSs is presented that simulate a subsurface crack of the same size with 4 values of its depth of occurrence, and the corresponding double-differentiation eddy current probe signals are experimentally investigated. A proposed method for manufacturing reference standards for simulating inclined cracks is presented. A number of studies are analyzed that consider possible reasons for the difference between eddy current probe signals from a natural crack and artificial defects. By means of calculations using the method of volume integral equations, it is shown that the main reason for the difference between eddy current probe signals from natural fatigue defects and artificial defects is their width (opening). The influence of the crack length on the features of the parametric type eddy current probe signal is considered, which must be taken into account when choosing the length of the cracks of the reference standards to ensure the sensitivity threshold and reproducibility of the inspection results. A statistically based method for reliable estimation of the parameters of the reference standards with natural defects is presented, which has been successfully used to evaluate reference standards with fatigue cracks in tubular specimens. alloys with variable thicknesses ranging from 45 to 65 mm while maintaining the same number of passes.
Keywords: reference standard, classification, eddy current method, non-destructive testing, eddy current probe, artificial defect, defect parameters

Received: 03.06.2025
Received in revised form: 15.08.2025
Accepted: 18.10.2025

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Suggested Citation

V.M. Uchanin (2025) Methodology of using standard specimens with defects for eddy current inspection: classification, typical examples, signals research and statistical method for parameters assessment. The Paton Welding J., 10, 36-48.

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