Ng, M.-F., Blackwood, D. J., Jin, H., Tan, T. L. (2021). Revisiting Cl-Induced Degradation of MnS Inclusions Using DFT. The Journal of Physical Chemistry C, 125(43), 24189–24195. https://doi.org/10.1021/acs.jpcc.1c07419
Abstract:
Cl-induced passivity breakdown is one of the major causes of corrosion for ferrous alloys. On the passive layer, manganese sulphide (MnS) inclusions are known to be the preferred sites for pit initiation. While its breakdown process has been examined, relatively less effort has been devoted to discover ways to mitigate the harmful process. Using DFT+U and ab initio molecular dynamics (AIMD) calculations, we investigated the initial stages of the Cl-induced degradation of MnS inclusions. We found that Cl adsorption on the MnS inclusion would lead to the formation of an amorphous MnxClySz complex on the surface. With increased Cl concentration, a thinned MnS inclusion could be resulted. More importantly, we examined the effects of alloying Cr, Fe and Mo on the inclusion against Cl-induced degradation. Our calculations showed that the addition of Mo can effectively mitigate the degradation process, suggesting a potential way to improve the corrosion resistance of ferrous alloys.
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Funding Info:
This research / project is supported by the A*STAR - Structural Metal Alloys Programme
Grant Reference no. : A18B1b0061