Overview
EN ISO 25239-4:2020 - Friction stir welding (FSW) - Aluminium - Part 4 specifies requirements for the specification and qualification of welding procedures used for friction stir welding of aluminium and its alloys. It defines how to prepare and qualify a preliminary welding procedure specification (pWPS) and a welding procedure qualification record (WPQR), the required tests and examinations, and the permissible range of qualification. This part excludes friction stir spot welding (covered by ISO 18785). Note that service or material-specific requirements can require additional testing beyond this standard.
Key Topics and Requirements
- Scope and terminology: Applies to aluminium and aluminium alloys; terms align with ISO 25239-1 and ISO/TR 25901.
- Welding procedure documentation: Guidance on the technical content of pWPS/WPS and how to record qualified procedures (WPQR).
- Qualification routes: Qualification based on a dedicated welding procedure test or on pre-production welding tests.
- Test pieces and specimen extraction: Requirements for shape, dimensions and preparation of test pieces used for qualification.
- Examination and testing:
- Visual inspection and acceptance criteria (references ISO 17637).
- Destructive tests (tensile, bend, fracture, macro/micro examinations) per referenced standards (e.g., ISO 4136, ISO 5173, ISO 9017, ISO 17639).
- Non‑destructive testing options are described (see informative Annex B).
- Range of qualification: Defines variables related to the fabricator, tooling, joint configuration and other process parameters that affect validity of the qualification.
- Process control: Allows alternative process control methods (for example, temperature-based control) and addresses thermal management and heat treatment considerations.
- Annexes and forms: Includes example pWPS/WPS forms, WPQR form with acceptance levels, and informative tests (e.g., hammer S-bend for lap welds).
Applications
EN ISO 25239-4:2020 is essential for organizations implementing friction stir welding of aluminium in safety- and performance-critical products. Typical applications include:
- Aerospace structures
- Marine and shipbuilding
- Railway carriages and rolling stock
- Food processing and hygienic equipment
- Consumer goods and automotive components
Using this standard helps ensure consistent weld quality, repeatable procedures, and documented qualification for regulatory compliance and supplier approval.
Who should use it
- Welding engineers and procedure developers
- Fabricators and production managers employing FSW
- Quality, inspection and NDT personnel
- Certification bodies and auditors
- Designers and procurement professionals specifying welded assemblies
Related Standards
Keywords: EN ISO 25239-4:2020, ISO 25239-4:2020, friction stir welding aluminium, FSW welding procedures, welding procedure qualification, pWPS, WPQR, aluminium alloys standards.