SIST EN ISO 15653:2018 PDF

Overview

EN ISO 15653:2018 - Metallic materials - Method of test for the determination of quasistatic fracture toughness of welds - specifies standardized methods to determine fracture toughness of welded joints in terms of stress intensity factor (K), crack tip opening displacement (CTOD, δ) and the experimental equivalent of the J‑integral (J). Published by CEN as the European adoption of ISO 15653:2018, the standard is intended to be used in conjunction with ISO 12135 and focuses on single‑point fracture toughness determinations for weld metal and heat‑affected zones (HAZ).

Key topics and requirements

• Fracture toughness measures: Procedures for evaluating K, CTOD (δ) and J as point values for welds.
• Specimen strategy: Use of fatigue precracked specimens that are notched after welding into a defined target area (weld metal or HAZ).
• Notch placement and assessment: Methods to evaluate whether a weld is suitable for notch placement in the target area and to verify that the fatigue crack samples the intended microstructure.
• Specimen design and orientation: Guidance on selecting specimen geometry and crack plane orientation to sample weld or HAZ regions effectively.
• Preparation and metallography: Requirements for pre‑machining metallographic assessment, post‑test metallography, and checking crack front straightness and pop‑in behavior.
• Testing procedure: Test apparatus, loading procedures and post‑test analysis steps (including choice of tensile properties and calculation methods).
• Limitations: The document describes point determinations and is not intended for producing full R‑curves (resistance‑to‑crack‑extension), though specimen preparation methods can support R‑curve work.
• Annexes and special topics: Informative and normative annexes cover notch examples, metallography, residual stress modification and pop‑in assessment; shallow‑notched bend specimen testing is also addressed.

Applications and users

EN ISO 15653:2018 is used where reliable fracture toughness data for welded joints are required for safety, design and qualification:

• Welding engineers and metallurgists validating weld procedures and assessing weld integrity.
• Materials testing laboratories performing fracture toughness testing on welds (K, CTOD, J).
• Structural and design engineers evaluating fracture resistance for pressure vessels, pipelines, ship structures, rail vehicles, and other safety‑critical welded components.
• Certification and quality assurance bodies requiring standardized fracture toughness evidence for compliance.

Related standards

• ISO 12135 - Fracture toughness testing of parent metal (to be used in conjunction with ISO 15653).
• EN ISO 15653:2018 - CEN adoption/official European version of ISO 15653:2018.

Keywords: EN ISO 15653:2018, fracture toughness of welds, CTOD, J‑integral, stress intensity factor K, fatigue precracked specimens, weld HAZ, notch placement, fracture testing standard.