In-situ corrosion studies of additively manufactured stainless steel by ambient pressure X-ray spectroscopy
|Coordinator||SWERIM AB - Material- och Processutveckling|
|Funding from Vinnova||SEK 500 000|
|Project duration||November 2020 - May 2022|
|Venture||Research infrastructure - utilisation and collaboration|
|End-of-project report||2020-03792_AlfaLaval_QuintusTechnology.pdf (pdf, 448 kB)|
Purpose and goal
Thanks to the project Alfa Laval and Quintus together with Swerim were able to test a measurement protocol allowing to use Ambient-Pressure XPS (APXPS) in combination with an electrochemical cell to study the evolution of the surface passive film in contact with electrolyte. The method was tested for AM 316L steel in two different electrolytes. We have confirmed that the APXPS data can be used to calculate the thickness and composition of the passive film.
Expected results and effects
We have tested 316L steel in two different electrolytes (1M NaCl and 0.1M HCl). The experiments in 0.1 M HCl were the most successful and allowed to follow a dissolution of Fe cations and thinning of the passive film during corrosion initiation. The film was shown to be enriched with Cr in the passive region and further dissolution was confirmed at higher potentials. Swerim has successfully tested the measurement procedure. Both Alfa Laval and Quintus technologies are now familiar with the technique and aware of its capabilities.
Planned approach and implementation
The measurements have been performed at HIPPIE beamline at MAX IV. The experiment is performed at ambient pressure while beaker with electrolyte and sample holder are placed on the bottom and top manipulator respectively. The sample is mounted on the same holder together with the SCE reference- and Pt counter electrode. The electrodes are then dipped in the beaker and the potential is applied. When the sample holder is pulled out of the beaker, the APXPS signal can be detected via this thin electrolyte film. The spectra are analyzed and the composition and thickness of the passive film are calculated.