Authors Rokosz, K. ; Hryniewicz, T. ; Simon, F. ; Rzadkiewicz, S.
Title Comparative XPS analyses of passive layers composition formed on duplex 2205 SS after standard and high-current-density electropolishing
Date 19.07.2016
Number 50881
Abstract In the paper, there are described XPS results of passive layers formed on duplex 2205 (EN 1.4462) stainless steel after a standard (EP50) and high-current density electropolishing (EP1000). The electrolyte based on orthophosphoric and sulfuric acids in proportion 1:4 was used. The survey and high resolution spectra of Cr 2p, Fe 2p, S 2p, P 2p are presented in the paper. Based on the survey of XPS spectrum it was possible to find the contamination of outer sub-layer consists mainly of nitrogen, sodium, chloride, potassium and partly oxygen and the inner passive sub-layer consists of iron, chromium, nickel, molybdenum, manganese, phosphorus, sulfur, silicon and partly oxygen. The obtained results show that in the passive layers formed on duplex 2205 stainless steel after a standard (EP50) and high-current density electropolishing (EP1000), the following oxides (FeO, Fe2O3, Fe3O4, Cr2O3), hydroxides (FeOOH, Cr(OH)3, CrOOH) and salts (FeSO4, Fe2(SO4)3, FePO4, CrPO4, Cr2(SO4)3) were detected. In the paper, besides iron and chromium compounds identification the authors propose two coefficients for passive surface characterization, i.e. chromium-to-iron coefficient (Cr/Fe) and phosphorus-to-sulfur (P/S). These two ratios obtained after the standard electropolishing (EP50) of 2205 SS are higher than those obtained after EP1000 treatment.
Publisher Tehnicki vjesnik
Citation Tehnicki vjesnik 23 (2016) 731-735

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