103914A novel integrity model for stainless steels in high temperature Nuclear applicationsClosedFeasibility StudiesInnovate UKIn long-term high temperature service, austenitic stainless steels show considerable microstructural development, with often life-limiting changes in mechanical properties. Currently industry relies on conservative mechanical test data to assess remaining plant life, without reference to the actual metallurgical condition. This project builds on an earlier Innovate UK funded study which demonstrated the feasibility of a method for classifying the microstructural condition of austenitic steels, correlating this to mechanical performance, and producing an innovative preliminary structrural integrity model. That project focussed on the life extension of the UK’s AGR fleet, in particular the austenitic steels used in heat exchangers for tubing and supports. This project will focus on the metallographic assessment of 250+ specimens creep tested between 550 and 700°C, for up to 190,000 hours and ten ex-AGR samples with lives up to 178,000 hours – all provided by EDF Energy Generation. With supplementary mechanical testing, these results will enable us to develop and validate the model to a commercialisable stage. Exploitation will enable Metamet to develop a new business stream in high temperature plant integrity.