Overview
EN ISO 11970:2025 - Specification and qualification of welding procedures for production welding of steel and nickel‑base castings - defines how to prepare and qualify a Welding Procedure Specification (WPS) and the associated Welding Procedure Qualification Record (WPQR) for production welding of steel castings (and nickel‑base castings). Published by CEN in alignment with ISO 11970:2025, this third edition supersedes the 2016 version and establishes the requirements for executing welding procedure qualification tests, the limits of validity of a qualified procedure, and the range of essential variables for practical welding operations. The standard primarily covers arc welding of steel castings, with principles applicable to other fusion processes by agreement between contracting parties.
Key Topics
- Scope and applicability: Qualification of WPS for production welding of steel and nickel‑base castings; primary focus on arc welding of steel castings.
- Preliminary WPS (pWPS): Preparation and documentation required before qualification testing.
- Test piece requirements: Shape, dimensions and welding procedures for qualification specimens.
- Examination and testing: Required non‑destructive testing (NDT) and destructive tests including transverse tensile, macro‑ and micro‑examination, impact and hardness tests.
- Range of qualification: Limits and transferability related to manufacturer, parent metal grouping and thickness, welding process, positions, joint type, filler metal, type of current, heat input, preheat/interpass temperatures and post‑weld heat treatment.
- Qualification records: WPQR content and Annex A record form guidance.
- Welder qualification and retesting: Criteria for welder qualifications and when retesting is required.
- Normative and informative annexes: Detailed testing procedures and record examples.
Applications
Who uses EN ISO 11970:2025 and why:
- Welding engineers and procedure writers - to develop and qualify WPS/WPQR for steel and nickel‑base casting production.
- Manufacturers of iron and steel castings - to ensure consistent, auditable welding procedures and to demonstrate compliance to purchasers.
- Quality assurance / inspection teams - to plan required NDT and destructive tests and interpret qualification limits.
- Purchasers and specifiers - to define additional tests or service‑specific requirements beyond the standard.
Practical uses include qualifying production welding processes for repaired or assembled castings, controlling heat input and preheat conditions, and documenting procedure validity across materials and thickness ranges.
Related Standards
- ISO 11970:2025 (international text endorsed by CEN as EN ISO 11970:2025).
- The standard acknowledges prior qualifications made to other specifications (for example ASME Section IX) and allows continuity where ranges of qualification conform.
- Prepared by ISO/TC 17 (Steel) in cooperation with CEN/TC 459/SC 11 (Steel castings and forgings).
Keywords: EN ISO 11970:2025, welding procedure specification, WPS qualification, WPQR, steel castings, arc welding, welding procedure qualification tests, preheat temperature, post‑weld heat treatment, non‑destructive testing.
