CEN/WS 021 - Small Punch Test Method for Metallic Materials

This Code of Practice gives guidance on the procedure to be followed when carrying out
Small Punch Creep tests. The objectives of such tests are to evaluate the creep behaviour of
materials exposed in operating plant components in order to provide data needed for plant
life and integrity assessment. The Code of Practice primarily addresses metallic materials
tested under creep loading but can also be used for other materials. Determination of tensile
test data at elevated temperature can also be realised using the proposed methodology. But
the methodology applied in Part B of this document should be applied.
The scope of the Code of Practice covers the following:
Test Piece
Test pieces are discs of specified dimensions procured from components or any other
source. They may be homogeneous or contain manufacturing features such as for example
joints, weldments, defects or coatings
Load
The load may be applied to the disc from a pneumatic, hydraulic or any other mechanical
source. The Code of Practice particularly addresses the usual situation where the load is
maintained constant throughout the test, but the general principles apply also to tests where
the load is cycled, with dwell periods.
Temperature
The test temperature will usually be within the creep range for the materials under test. The
Code of Practice specifically addresses the usual situation where the temperature is
maintained constant throughout the test, but the general principles also apply to thermal
cycling with or without dwell periods.
Environment
The test pieces will usually be tested in an inert gas environment. However, the general
principles should also apply when other environments are used. Although special
precautions will be necessary where hazardous or corrosive environments are used, these
are not detailed in this document.