Overview - ISO 17405:2022 (Ultrasonic testing of claddings)
ISO 17405:2022 is an International Standard for non-destructive testing (NDT) that specifies techniques for manual ultrasonic testing of claddings on steel applied by welding, rolling and explosion. The document defines probe selection, instrument settings and test procedures (pulse‑echo technique) for detecting two‑dimensional and three‑dimensional discontinuities in the cladding and the cladding–parent metal interface. It does not provide acceptance criteria or define the extent of testing.
Key topics and technical requirements
- Test method: Manual ultrasonic pulse‑echo testing focused on claddings and the interface region.
- Probe types: Single‑transducer and dual‑transducer straight‑beam probes for longitudinal waves; dual‑transducer angle‑beam probes for other orientations.
- Frequencies: Nominal frequency selected by purpose and material; 2 MHz to 6 MHz preferred.
- Angle‑beam guidance: Beam angle in the cladding should be between 65° and 80° for dual‑transducer angle‑beam probes.
- Probe adaptation: Maximum gap between probe face and curved surface ≤ 0.5 mm. For flat probes on cylindrical surfaces the gap can be estimated using g = a² / (4D) (a = probe dimension, D = object diameter).
- Instrument requirements: Instruments and probes shall conform to ISO 22232‑1/‑2 and the full test system checked per ISO 22232‑3. An expanded time base (“zoom mode”) is required.
- Calibration and sensitivity: Use representative reference blocks (cladding type, thickness and surface prep matching the test object). Example reference reflectors: side‑drilled holes (e.g. 3 mm dia.) for volumetric defects, flat‑bottomed holes for planar defects, notches for perpendicular planar defects. Echo height for reference reflectors is set to 40% of full screen height.
- Personnel: Operators must be qualified per ISO 9712 or equivalent.
Applications and users
ISO 17405 is practical for organizations that inspect cladded steel components where the integrity of the cladding and its bond to parent metal is critical, including:
- NDT technicians and inspection engineers
- Welding and cladding contractors
- Asset owners and maintenance teams in petrochemical, power generation, nuclear, pressure vessels and pipeline industries
- Quality managers specifying inspection procedures for welded, rolled or explosively applied claddings
This standard helps ensure consistent ultrasonic test technique, probe selection and calibration practice when assessing cladding integrity, while leaving acceptance criteria to project or regulatory specifications.
Related standards
- ISO 5577 - Ultrasonic testing vocabulary
- ISO 9712 - Qualification and certification of NDT personnel
- ISO 22232‑1 / ‑2 / ‑3 - Characterization and verification of ultrasonic test equipment (instruments, probes, combined equipment)
- ISO 2400 (referenced for calibration block examples)
Open preview (PDF)Non-destructive testing — Ultrasonic testing — Technique of testing claddings produced by welding, rolling and explosion
