Detecting Structure and Composition of Passive Film on 316l Stainless Steel Formed in Simulated Concrete Pore Solution with the Addition of Hco3-/Co32- and Cl-

Abstract

The structural and compositional evolution of the passive films formed on the 316L in simulated concrete pore solution with the addition of HCO3-/CO32- and Cl- is studied. A bi-layer film is observed on 316L after immersion in alkaline concrete pore solution. In the carbonated concrete pore solution, Fe(II) compounds are dissolved by HCO3-/CO32-, contributing to the formation of randomly distributed nano-scaled pits below the Cr-enriched skeleton and the deterioration of the corrosion resistance. With the introduction of Cl-, Mo is stimulated and accumulates at the outermost of the film, thereby inhibiting the ingress of HCO3-/CO32- and restoring the corrosion resistance.

Keywords: Passive film, Aberration-corrected TEM, Concrete pore solution, 316L stainless steel