Passivity breakdown on 436 ferritic stainless steel in solutions containing chloride. Issue 4 (April 2019)

• Record Type: Journal Article
• Authors: Wang, Jiaming; Qian, Shengsheng; Li, Yanhui; Macdonald, Digby D.; Jiang, Yiming; Li, Jin
• Is Part Of: Journal of materials science & technology. Volume 35:Issue 4(2019)
• Page Start: 637
• Page End: 643
• Publication Date: 2019-04
• Subjects: 436 ferrite stainless steel -- Passivity breakdown -- Point defect model -- Chloride ions; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2018.10.030
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: Passivity breakdown on 436 ferritic stainless steel (FSS) has been investigated in solutions containing different concentrations of chloride at 25 °C and interpreted in terms of the point defect model (PDM). The measured near-normal distributions of passivity breakdown potentials for 436 FSS under experimental conditions are in good agreement with the calculated results according to the PDM. The linear dependence of breakdown potential on the square root of potential scanning rate, which was described by the PDM, provides the estimation of the critical concentration of condensed vacancies at the metal/film interface, which leads to the passivity breakdown. This value is in good agreement with that calculated from the microstructure properties of the alloy substrate and the barrier layer of the passive film. This study demonstrates the validity of the PDM in describing the passivity breakdown on 436 FSS in NaCl solutions.