Overview
EN ISO 17643:2015 - "Non‑destructive testing of welds - Eddy current examination of welds by complex plane analysis" - defines eddy current testing (ECT) methods for detection of surface‑breaking and near‑surface planar discontinuities, primarily in ferritic materials (weld metal, heat‑affected zone, base material). The standard covers use on coated and uncoated components during fabrication and in service (onshore and offshore) and applies to welds of almost any configuration. Where not otherwise specified, the general principles of ISO 15549 apply. Note: very rough surface finishes can reduce the accuracy of eddy current testing.
Key Topics and Requirements
- Scope of detection: Surface‑breaking and near‑surface planar discontinuities (mainly ferritic materials); use on non‑ferritic materials may be specified in application standards.
- Personnel and procedures: Testing should be performed by qualified personnel (recommended per ISO 9712) and follow written procedures (per ISO 15549) when required.
- Instrumentation:
- Instruments must perform complex‑plane analysis (amplitude and phase measurement).
- Frequency capability: 1 kHz to 1 MHz for instruments.
- Display must allow freezing traces and be visible in expected lighting.
- Phase control: 360° rotation in steps of no more than 10°.
- Probes:
- Coating thickness/material evaluation probes: absolute mode, marked frequency range 1 kHz–1 MHz.
- Weld testing probes (for ferritic welds): orthogonal/tangential coil assemblies enabling differential measurements; probe frequency 100 kHz–1 MHz; probe geometry chosen to match weld shape.
- If probe covers are used, they must be in place during calibration.
- Calibration:
- Use a calibration block of the same material with EDM notches of 0.5 mm, 1.0 mm, and 2.0 mm depth (tolerance ±0.1 mm) unless otherwise specified.
- Surface and coating considerations:
- ECT can detect cracks through non‑metallic coatings up to 2 mm thickness; thicker coatings require prior demonstration of sensitivity.
- Conductive coatings (e.g., thermally sprayed aluminium) can mask cracks by depositing conductive material into surface openings.
Applications
- Detection of surface and near‑surface cracks in welded joints during fabrication and in‑service inspection.
- Suitable for onshore and offshore structures, pressure equipment, piping, vessels and welded components where ferritic materials are used.
- Applicable to coated and uncoated surfaces, complex weld geometries and maintenance inspections.
Who Uses This Standard
- NDT technicians and inspectors performing eddy current testing of welds.
- Welding quality and inspection engineers in fabrication shops, petrochemical, power generation, and offshore industries.
- Certification bodies, inspection companies and asset owners specifying acceptance criteria and testing procedures.
Related Standards
- ISO 15549 - Eddy current testing - General principles
- ISO 15548‑1/2/3 - Equipment and probe characteristics and verification
- ISO 9712 - Qualification and certification of NDT personnel
- ISO 12718 - Eddy current testing vocabulary
Keywords: EN ISO 17643:2015, eddy current testing, weld inspection, non‑destructive testing, complex plane analysis, ferritic materials, calibration block, NDT.