Corrosion Investigation by Scanning Electrochemical Microscopy of AISI 446 and Ti-Coated AISI 446 Ferritic Stainless Steel as Potential Material for Bipolar Plate in PEMWE  

作　　者：Andrea Kellenberger Nicolae Vaszilcsin Mircea Laurentiu Dan Ion Mitelea Alexandru Adrian Geana Sigrid Lædre Corneliu M.Craciunescu 

机构地区：[1]Faculty of Industrial Chemistry and Environmental Engineering,Politehnica University Timisoara,Piata Victoriei 2,300006,Timisoara,Romania [2]Faculty of Mechanical Engineering,Politehnica University Timisoara,Piata Victoriei 2,300006,Timisoara,Romania [3]SINTEF Industry,7465,Trondheim,Norway

出　　处：《Acta Metallurgica Sinica(English Letters)》2024年第4期607-619,共13页金属学报（英文版）

基　　金：funding from the EEA Grants 2014-2021,under Project contract No.2/2019 CoDe-PEM(EEA RO-NO-2018-0502).

摘　　要：The components of proton exchange membrane water electrolysers frequently experience corrosion issues, especially at high anodic polarization, that restrict the use of more affordable alternatives to titanium. Here, we investigate localized corrosion processes of bare and Ti-coated AISI 446 ferritic stainless steel under anodic polarization by scanning electrochemical microscopy (SECM) in sodium sulphate and potassium chloride solutions. SECM approach curves and area scans measured at open-circuit potential (OCP) of the samples in the feedback mode using a redox mediator evidence a negative feedback effect caused by the surface passive film. For the anodic polarization of the sample, the substrate generation-tip collection mode enables to observe local generation of iron (II) ions, as well as formation of molecular oxygen. For the uncoated AISI 446 sample, localized corrosion is detected in sodium sulphate solution simultaneously with oxygen formation at anodic potentials of 1.0 V vs. Ag/AgCl, whereas significant pitting corrosion is observed even at 0.2 V vs. Ag/AgCl in potassium chloride solution. The Ti-coated AISI 446 sample reveals enhanced corrosion resistance in both test solutions, without any evidence of iron (II) ions generation at anodic potentials of 1.2 V vs. Ag/AgCl, where only oxygen formation is observed.

关 键 词：Ferritic stainless steel CORROSION Ti coating Scanning electrochemical microscopy(SECM) Magnetron sputtering Proton exchange membrane water electrolysis(PEMWE) 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TG142.71[一般工业技术—材料科学与工程]