Naslov
Environmental factors affecting the corrosion behaviour of stainless steel in aluminium smelter: Influence of fluoride concentration and pH value

Autori
Mišković, Ivana ; Pilić, Zora ; Dragičević, Ivan ; Višekruna, Antonija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Challenges in Modern Analytical Chemistry / - , 2011, EN59-EN59

Skup
EuroAnalysis 16 - European Conference on Analytical Chemistry

Mjesto i datum
Beograd, Srbija, 11.11.2011. - 15.11.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Iron, stainless steel, aluminium smelter, corrosion control
(stainless steel, aluminium smelter, corrosion control)

Sažetak
Iron and stainless steel have been largely used as construction materials in processing industry. In the aluminium smelter, one of the main environmental problems is air emissions which include fluorides. Environmental concerns are also a reason for corrosion control. From an industrial point of view, presence of fluorides is an important issue limiting the service life of the equipment used in processing industry. The fluoride concentration in aluminium smelter “Aluminij” d.d. Mostar was determined by potentiometry and obtained values were below the maximum allowed concentration (5 mg m-3). These results were base for setting up the experimental conditions under which corrosion of stainless steel was studied. The influence of fluoride concentration (0.01 i 0.1 mol L-1) and pH value of solution (4.5, 5.5 ; 6.5) on electrochemical behaviour of stainless steel 304 was studied by combination of electrochemical techniques. The growth and mechanism of the passive film formation on stainless steel 304 in fluoride solution were studied by cyclic voltammetry (CV). Under the assumption that the composition of the passive film is Cr2O3 the values of field strength, conductivity and half-jump distance were calculated. The electrochemical properties of the spontaneously passivated electrodes at the open circuit potential were studied by electrochemical impedance spectroscopy (EIS). The charge transfer resistance and the electrode capacitance were determined. The experimental data are interpreted in terms of the point defect model, assuming that predominant point defects on passive film of stainless steel 304 are cation vacancies. Diffusivity and concentration of point defects were estimated from the Warburg-type impedance. The CV and EIS results indicate that the increase of fluoride concentration leads to increase dissolution of stainless steel 304, while influence of pH value is negligible in studied experimental conditions.

Izvorni jezik
Engleski

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