Overview - EN ISO 204:2023 (Uniaxial creep testing in tension)
EN ISO 204:2023 (ISO 204:2023) is the CEN-endorsed international standard that defines the method of test for uniaxial creep testing in tension of metallic materials. It specifies procedures for continuous and interrupted creep tests, stress-rupture tests, and verification tests to confirm that a material can exceed a predetermined time under a given force. The document replaces EN ISO 204:2018 and is prepared by ISO/TC 164 in collaboration with CEN/TC 459/SC 1.
Key topics and technical requirements
- Test types covered
- Uninterrupted creep tests with continuous extension monitoring
- Interrupted creep tests with periodic elongation measurement
- Stress-rupture tests (time to fracture)
- Verification tests where time-to-exceed is checked
- Apparatus and measurement
- Requirements for testing machines and load application
- Extension and elongation measuring devices (gauge/extension systems)
- Heating devices, temperature measurement and thermocouple guidance
- Calibration and permissible temperature deviations
- Test pieces and preparation
- Shape, dimensions and marking of smooth and notched test pieces (including circumferential V and blunt/Bridgman notches)
- Determination of original cross-sectional area and reference/gauge length
- Test procedure and data recording
- Heating, application of force, planned/accidental interruptions
- Recording of temperature and elongation/extension; generation of elongation‑time or extension‑time curves
- Results, validity and uncertainty
- Determination and expression of results, test validity criteria
- Guidance on estimating measurement uncertainty (GUM principles) and extrapolation of creep rupture life
- Informative and normative annexes
- Thermocouple drift and calibration, notched specimen testing methods, uncertainty estimation, representation/extrapolation of results
Practical applications and who uses this standard
EN ISO 204:2023 is essential for organizations involved in high‑temperature performance assessment of metals:
- Materials testing laboratories performing creep and stress‑rupture tests
- Metallurgists and R&D teams developing creep‑resistant alloys
- Component designers and engineers in power generation, petrochemical, aerospace and manufacturing industries who require reliable life‑assessment data
- Quality assurance and certification bodies that verify material conformity and long‑term performance
Using this standard ensures consistent, reproducible creep test results for material selection, lifetime prediction and compliance with regulatory or procurement requirements.
Related standards
- Supersedes EN ISO 204:2018
- Prepared by ISO/TC 164 (Mechanical testing of metals) and linked to CEN/TC 459/SC 1
- References the Guide to the Expression of Uncertainty in Measurement (GUM) within its uncertainty annexes
Keywords: EN ISO 204:2023, ISO 204:2023, uniaxial creep testing, metallic materials, creep test, stress rupture, thermocouples, temperature measurement, creep rupture life, mechanical testing of metals.
