What is this standard about?
This is part one in a series of four standards which detail how to conduct tensile testing of metallic materials. This part looks at tensile testing methods for metallic materials at room temperature. It brings together the European and international testing methods.
The other standards in the series are:
- Part 2: Method of test at elevated temperature (published 2011)
- Part 3: Method of test at low temperature (published 2015)
- Part 4: Method of test in liquid helium (published 2015)
Who is this standard for?
- Designers and engineers of metallic products and components
- Specifiers
- Insurers
It will also be a useful reference for major fabrication contracts between manufacturers and customers.
Why should you use this standard?
It specifies the method for tensile testing of metallic materials and defines the mechanical properties which can be determined at room temperature.
Two standard methods of testing speeds are available. The first (Method A) is based on strain rates (including crosshead separation rate); the second (Method B) is based on maintaining a stress rate during elastic region of tensile test.
Method A is intended to minimize the variation of the test rates during the moment when strain rate sensitive parameters are determined, and to minimize the measurement uncertainty of the test results.
Complementary recommendations for computer controlled testing machines are also indicated.
What’s changed since the last update?
The standard was revised to clarify how the recommended method of test control can be achieved. In 2009, ISO 6892-1 introduced Method A, which is based on maintaining a strain rate. However many people were under the misapprehension that Method A is only achievable using equipment capable of closed-loop strain control. This is not true. It is possible to conform to Method A using a constant crosshead separation rate.
To make this clearer, ISO 6892-1:2016 additionally sub-divides Method A into Method A1 (Closed-Loop Strain Control) and Method A2 (Constant Crosshead Separation Rate). It is hoped that this further clarification will assist test labs that are transitioning from Method B to Method A and monitoring the specimen strain rate.
The benefits remain the same: Method A is intended to minimize both the variation of the test rates during the moment when strain-rate sensitive parameters are determined and the measurement uncertainty of the test results. More repeatable and comparable results will be produced and there can be considerable time savings when Method A1 is used.