Draft CWA ‘The Standardization of the Impression Creep Test’

The CEN Workshop ‘The Standardization of the Impression Creep Test’ has developed its first draft CWA.

The document provides a common test methodology and data interpretation for the impression creep test amongst laboratories using, or planning to use, this specialised technique.


In order that operators of power plant can use impression creep testing as an integral part of the remanent life strategy they adopt for their high temperature components, impression creep needs to become a more generally accepted test method. There is an associated need for standardisation of both the test technique itself and the use that is made of the data generated. This should lead to acceptance of the approach by power plant operators and third parties such as plant insurers, boiler inspectors, etc.


The impression creep test method, using a rectangular indenter, has been used extensively in the last 10 years, for a number of UK and EU projects and for industrial applications (e.g. TWI, British Energy, RWE Generation UK, Structural Integrity Associates). Some industrial organizations have already built or are in the process of developing the test facilities for impression creep testing. EPRI has included impression creep testing into a collaborative (~ 25 partners) research programme in order to assess the practicality of the technique.


This document builds on, and updates, earlier recommendations/guidelines produced for impression creep testing.


The draft CWA is now available for commenting. You are kindly invited to submit comments on the draft CWA to the WS secretary Ms. Katherine IMBERT, using the below commenting form.


Deadline: 8 June 2022


Download the documents:


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