What is ISO 204 - Metallic materials about?
ISO 204 is a safety standard on metallic materials. Metallic materials is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. ISO 204 specifies the methods for:
- Uninterrupted creep tests with continuous monitoring of extension
- Interrupted creep tests with periodic measurement of elongation
- Stress rupture tests where normally only the time to fracture is measured
- A test to verify that a predetermined time can be exceeded under a given force, with the elongation or extension not necessarily being reported
ISO 204 describes the percentage permanent extension which is the extension at the end of unloading and at test temperature determined as the difference between the percentage total extension, et, and the sum of percentage elastic extension, ee, plus the percentage anelastic extension, Ek, expressed as a percentage of the reference length, Lr,
Who is ISO 204 - Metallic materials for?
ISO 204 on the uniaxial creep testing in tension is relevant to:
- Testing authorities
- Manufacturers and suppliers of tensile testing equipment
- Mechanical engineers
- Metallurgists
- Metallurgical engineers
Why should you use ISO 204 - Metallic materials?
Creep is the phenomenon exhibited by materials that slowly deform when subjected to loading at elevated temperatures. ISO 204 is concerned with the method used to measure such material behaviour. ISO 204 includes temperature measurement using thermocouples and their calibration creep testing test pieces with circumferential V and blunt (Bridgman) notches, estimation of measurement uncertainty, methods of extrapolation of creep rupture life, and information about computer compatible representation of standards. ISO 204 incorporates many recommendations developed through the European Creep Collaborative Committee (ECCC). ISO 204 summarizes vital information which should help the user to choose a suitable test type for their needs (i.e., uninterrupted, interrupted, or combined) and apply the established methodology developed within the European Creep Collaborative Committee. Overall, ISO 204 is useful as it assists with the uniaxial creep testing in tension in metallic materials.
What’s changed since the last update?
BS EN ISO 204:2018 replaces the second edition ISO 204:2009, which has been technically revised. The main changes compared to the previous edition are as follows:
- Some of the symbols have been changed to achieve harmonization with the ISO 6892 series
- For the purpose of BS EN ISO 204:2018, the terms “fracture” and “rupture” are interchangeable