The company has recently participated in a project which was 75% funded by Innovate UK under their competition “Developing the UK Civil Nuclear Supply Chain”. Led by Metamet Consultants Ltd – part of the R-TECH Materials Group, the project addressed two significant applications in the nuclear industry: life extension of the UK’s ageing fleet of AGR reactors and materials selection for potential new generation High Temperature Reactors. Based on research already conducted by the partnership, in conjunction with Swansea University, the project represents a key stage in a growing joint research activity.
Titled “A condition-based structural integrity and remaining life model for austenitic stainless steels”, the feasibility study has focussed on structural integrity issues arising from the continued life extension of the AGR fleet – in particular with the austenitic steels used in heat exchangers for tubing and supports. Operating in the creep regime, these materials show considerable microstructural development in service, with consequent changes in mechanical properties. The work has included an experimental programme comprising creep, tensile, and impact testing of pre-aged Type 304 and 316 steels, with associated metallographic studies. A formal method of classifying microstructural development in these materials has been generated. The kinetics of this development have been modelled and linked to a preliminary model of the resultant mechanical behaviour. A demonstration software package that estimates remaining creep life on the basis of observed microstructural state, using the preliminary model, has been produced.
Further work is in progress, extending the materials range to include welds and accessing longer-term aged material.
A paper based on this work has been published:
- Bagnall, S.L., Brear, J.M., Reed, A.W.B.
“Development of a classification system for the microstructural evolution of austenitic stainless steels”
ESIA13 – 13th International Conference on Engineering Structural Integrity Assessment,
FESI – UK Forum for Engineering Structural Integrity, Manchester, UK, 19- 20 May 2015