Overview
ISO 23864:2021 - Non‑destructive testing of welds - Ultrasonic testing - Use of automated total focusing technique (TFM) and related technologies - specifies how to apply the Total Focusing Technique (TFM) and related ultrasonic technologies for semi‑ or fully‑automated inspection of fusion‑welded joints. The standard covers welded components in metallic, homogeneous and isotropic materials (minimum thickness 3.2 mm) such as low‑carbon steels and common aerospace aluminium and titanium alloys. It applies to full‑penetration welds of simple geometry in plates, pipes and vessels and defines four testing levels (A, B, C, D) corresponding to different probabilities of detection.
Key technical topics and requirements
- Scope and applicability: TFM for semi‑automated and fully automated ultrasonic testing of welds in isotropic, homogeneous metallic materials (min 3.2 mm).
- Testing levels: Four defined levels (A–D) with guidance on selection according to detection requirements.
- Techniques: Side scanning (wedge/adjacent to weld cap) and top scanning (flexible delay lines, immersion, or contact after weld cap removal).
- Personnel and equipment: Requirements for personnel qualifications, instrument capabilities, probes, and scanning mechanisms.
- Preparation and setup: Pre‑test information, written procedures, volume to be tested, scan increment settings, geometry and surface preparation, couplants and temperature considerations.
- Imaging and analysis: Imaging of typical weld discontinuities, verification of test setup, range/sensitivity settings, gain corrections, and procedure verification.
- Reference blocks and calibration: Guidance on reference/test blocks, reference reflectors and equipment checks.
- Data and reporting: Data storage, interpretation of TFM images, classification, sizing (location, length, amplitude/height), and test reporting.
- Limitations: The document states it does not include specific acceptance levels for discontinuities; it outlines how to assess indications by amplitude/length or height/length.
Practical applications
- Production quality control for welded components in fabrication shops
- In‑service inspection and condition monitoring of pipelines, pressure vessels and structural welds
- Post‑repair verification and certification testing
- High‑resolution volumetric inspection where precise locating and sizing of weld discontinuities is required
Who should use this standard
- NDT engineers and technicians performing ultrasonic weld inspection
- Inspection companies and QA/QC managers in oil & gas, aerospace, power generation, shipbuilding, and fabrication
- Welding engineers, asset owners and maintenance teams specifying inspection procedures
- Equipment manufacturers and integrators developing automated TFM systems
Related standards
Keywords: ISO 23864:2021, TFM, total focusing technique, ultrasonic testing, weld inspection, NDT, automated inspection, phased array, weld discontinuities.