Investigation of early stages of phase decomposition in duplex stainless steels by in situ SANS
| Reference number | |
| Coordinator | Swerim AB - Swerim AB, Kista |
| Funding from Vinnova | SEK 500 000 |
| Project duration | October 2018 - November 2019 |
| Status | Completed |
| Venture | Research infrastructure - utilisation and collaboration |
| Call | Research infrastructure - utilisation and collaboration: Industrial pilot projects for neutron and photon experiments at large scale research infrastructures - 2018 |
| End-of-project report | 2018-03258_Outokumpu_HaldorTopso1.pdf (pdf, 408 kB) |
Important results from the project
The goal with this project was to analyse the early stages of phase separation in duplex stainless steels at elevated temperatures. The purpose was to help the participating companies with means on how to counteract or mitigate the consequences of phase separation on mechanical properties during manufacture, fabrication and in service. Successful measurements were carried out using the SANS technique which all participants of the project has learnt from via participation in the measurements, in project meetings and written reports.
Expected long term effects
The results from the SANS measurements were according to expectations, and some results above alternatively unexpected. These results were combined and correlated with property results which also gave interesting aspects on the issue of testing at ambient temperature versus properties at service temperature. All results are gathered in a technical report available only for the participating companies and a discussion is ongoing if certain of the achieved results within the project can be protected.
Approach and implementation
The project was run with the participation of Outokumpu Stainless, Haldor Topsoe, KTH and Swerim. In the previous project which was the foundation for this project also OKG, Forsmarks Kraftgrupp and Ringhals participated. The measurements were carried out at the SANS2D instrument at the ISIS Neutron and Muon Source in the UK. In-situ measurements on specimens at elevated temperatures to study how the microstructure is affected in the early stages were conducted. Measurements were also carried out on specimens heat treated at these temperatures in advance up to 500 hours.