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XPS analysis of AISI 304L stainless steel surface after electropolishing

Rokosz K., Hryniewicz T., Simon F., Rzadkiewicz S.

Advances in Materials Science

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2015

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Vol. 15, nr 1(43)

21--29

EN

In the paper, the passive surface layers of AISI 304L after standard (EP50) and very-high-current density electropolishing (EP1000) in a mixture of orthophosphoric and sulfuric acids in a 1:4 ratio, are presented. The main finding of the presented studies is enrichment of the steel surface film in chromium: total chromium to total iron ratio was equal to 6.6 after EP50 and to 2.8 after EP1000; on the other hand, chromium compounds to iron compounds ratio was equal to 10.1 after EP50, and 3.9 after EP1000.

2

XPS analysis of AISI 316L (EN 1.4404) austenitic stainless steel surfaces after passivation in nitric acid HNO3

Rokosz K., Hryniewicz T., Rzadkiewicz S.

Autobusy : technika, eksploatacja, systemy transportowe

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2014

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R. 15, nr 6

244-247

EN

The XPS results of AISI 316L passive surface layer after mechanical MP and electrochemical (EP, MIX) polishing with additional passivation in 20 vol% nitric acid HNO3 at 50 °C for 30 min are presented. The studies revealed the highest iron Fe 2p and chromium Cr 2p signals from surface layer after electrochemical polishing without stirring EP and passivation in HNO3 whereas the lowest signals were recorded after mechanical polishing MP and similar passivation. After the passivation of abrasively treated MP samples done the atomic concentration of chromium compounds was over 93 at% and after passivation of electropolished EP and MIX samples the atomic percentage of chromium compounds was about 88 at% of the whole chromium concentration. The iron compounds after MP equaled about 65 at%, and after EP and MIX about 58 at% of the whole amount of detected iron. In all samples and all studied passive layers mainly oxides and hydroxides as well as sulfates and phosphates of iron and/or chromium were detected. Presented results can be used as reference data for the analysis of other passive layers usually obtained after chemical and electrochemical treatments as well as electro-machining operation.

PL

W artykule przedstawiono wyniki XPS warstw wierzchnich po pasywowaniu w 20 obj% HNO3 w temperaturze 50 °C przez 30 minut powierzchni na stopowej stali austenitycznej AISI 316L zarówno po wcześniejszej obróbce mechanicznej MP, jak i standardowym polerowaniu elektrochemicznym bez mieszania EP jak i z mieszaniem elektrolitu MIX. Odnotowano największą sygnał zarówno dla żelaza Fe 2p, jak i dla chromu Cr 2p w warstwie wierzchniej po standardowym elektropolerowaniu EP, natomiast najmniejszy sygnał został zarejestrowany dla pasywowanej powierzchni stali polerowanej mechanicznie. Po pasywacji, w pasywnej warstwie wierzchniej znajdowały się związki chromu i żelaza: odpowiednio po MP ponad 93 at% i 65at%, natomiast po EP i MIX około 88 at% i 58 at%. We wszystkich zbadanych warstwach pasywnych przeważały tlenki i wodorotlenki oraz fosforany i siarczany żelaza i/lub chromu. Zaprezentowane wyniki należy traktować jako punkty odniesienia do dalszych studiów nad warstwami pasywnymi otrzymywanymi poprzez chemiczne, elektrochemiczne oraz elektromechaniczne obróbki.

3

Xps Study Of Aisi 316L Ss Surfaces After Mechanical And Electrochemical Polishing and Chelating/Electro-Chelating Treatments

Rokosz K., Hryniewicz T.

Advances in Materials Science

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2014

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Vol. 14, nr 1(39)

31--41

EN

In the paper, there are presented the analyses of iron Fe2p3/2 and chromium Cr2p3/2 and oxide O1s XPS spectra of surfaces obtained after abrasive and electrochemical polishing with additional treatment as chemical chelating in the solution containing of 10% Citric Acid and 2% Ethylenediaminetetraacetic Acid. There was also performed electro-chelating after mechanical polishing in the electrolyte for chemical chelating. The maximum values of chromium compounds to iron compounds ratio were obtained after electropolishing with and without stirring with chemical chelating in Citric Acid and EDTA and they were in rage from 3.5 to 3.6. The minimum value was obtained for the steel surface after abrasive polishing and electro-chelating and was equal 1.3. After electrochemical polishing and chemical passivation in the surface layer there were detected FeO and Cr(OH)3 as dominated compounds. After abrasive polishing and electro-chelating there were mostly Fe2O3 and Cr2O3.

4

Cr/Fe Ratio by Xps Spectra of Magnetoelectropolished Aisi 316L SS Using Linear, Shirley and Tougaard Methods of Background Subtraction

Hryniewicz T., Rokosz K.

Advances in Materials Science

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2013

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Vol. 13, nr 1(35)

11--20

EN

In the paper, the analyses of Fe2p3/2 and chromium Cr2p3/2 XPS spectra with fitting by symmetrical and asymmetrical line shapes as well as using Linear, Shirley and Tougaard Method of Background Subtraction are presented. The calculations are performed on AISI 316L SS biomaterial after magnetoelectropolishing MEP operation. It was found, the chromium-to-iron ratio after magnetoelectropolishing MEP for other analyses could be in the range from 2.2 to 6.2 depending on the line shapes as well as type of backgrounds used to XPS spectra fitting. The most important for comparison the surface layers concerning the Cr/Fe ratio is to use the same line shape and backgrounds for all analyses.