ISO 12135:2021
Metallic materials - Unified method of test for the determination of quasistatic fracture toughness

Standard No.

ISO 12135:2021

Release Date

2021

Published By

International Organization for Standardization (ISO)

Latest

ISO 12135:2021

Scope

This document specifies methods for determining fracture toughness in terms of K, δ, J and R-curves for homogeneous metallic materials subjected to quasistatic loading. Specimens are notched, precracked by fatigue and tested under slowly increasing displacement. The fracture toughness is determined for individual specimens at or after the onset of ductile crack extension or at the onset of ductile crack instability or unstable crack extension. In cases where cracks grow in a stable manner under ductile tearing conditions, a resistance curve describing fracture toughness as a function of crack extension is measured. In some cases in the testing of ferritic materials, unstable crack extension can occur by cleavage or ductile crack initiation and growth, interrupted by cleavage extension. The fracture toughness at crack arrest is not covered by this document. Special testing requirements and analysis procedures are necessary when testing weldments, and these are described in ISO 15653 which is complementary to this document. Statistical variability of the results strongly depends on the fracture type, for instance, fracture toughness associated with cleavage fracture in ferritic steels can show large variation. For applications that require high reliability, a statistical approach can be used to quantify the variability in fracture toughness in the ductile-to-brittle transition region, such as that given in ASTM E1921. However, it is not the purpose of this document to specify the number of tests to be carried out nor how the results of the tests are to be applied or interpreted.

ISO 12135:2021 Referenced Document

• ISO 3785 Metallic materials — Designation of test specimen axes in relation to product texture*， 2023-05-01 Update
• ISO 7500-1 Metallic materials - Calibration and verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system
• ISO 9513 Metallic materials.Calibration of extensometer systems used in uniaxial testing; Technical Corrigendum 1

ISO 12135:2021 history

• 2021 ISO 12135:2021 Metallic materials - Unified method of test for the determination of quasistatic fracture toughness
• 2016 ISO 12135:2016 Metallic materials - Unified method of test for the determination of quasistatic fracture toughness
• 2008 ISO 12135:2002/Cor 1:2008 Metallic materials — Unified method of test for the determination of quasistatic fracture toughness TECHNICAL CORRIGENDUM 1
• 2002 ISO 12135:2002 Metallic materials - Unified method of test for the determination of quasistatic fracture toughness