X-ray photoelectron microscopy study of the homogenization process in duplex stainless steels
| Reference number | |
| Coordinator | SWERIM AB - Swerim AB, Kista |
| Funding from Vinnova | SEK 498 241 |
| Project duration | March 2020 - December 2021 |
| Status | Completed |
| Venture | Research infrastructure - utilisation and collaboration |
| Call | Industrial pilot projects for the utilisation of neutron and photon based techniques at large-scale infrastructures - Autumn 2019 |
| End-of-project report | 2019-05278_Outokumpu_Sandvik.pdf (pdf, 275 kB) |
Important results from the project
The project was carried out by Sandvik Materials Technologies (SMT), Outokumpu and Swerim. The Spectroscopic PhotoElectron Low Energy Electron Microscope at MAX IV was used. The aim was to give new insights into the sigma-phase precipitation and homogenization dynamics in duplex steel while studying the segregation of the alloying elements. The project has shown that the instrument is a powerful tool to study evolution of surface chemical composition during heat treatments. Particularly precipitation of secondary phases. Several limitations of the technique were identified.
Expected long term effects
The project generated valuable knowledge about the dynamics of sigma phase precipitation and the effects of vacuum annealing on surface chemical composition in duplex steels. The ability of the instrument for in-situ heating and simultaneous measurements was confirmed. The strict requirement for ultra-high vacuum was identified as the main obstacle for obtaining homogenization of sigma phase due to the surface effects associated with annealing in vacuum. The results will be further evaluated by Swerim, SMT, and Outokumpu Stainless for implementation in computational models.
Approach and implementation
The measurements were performed at MAXPEEM beamline at MAX IV in close collaboration with the instrument scientist. The sample preparation and data analysis routines were tested and will be used by Swerim in other projects involving Spectroscopic PhotoElectron Low Energy Electron Microscope (SPELEEM). We foresee in the future that the MAXPEEM beamline can become a platform for studying surface evolution in industrial processes involving heat treatments.