Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Marek Marczewski"

Corrosion resistance of 304 stainless steel after anodic polarization in choline chloride-oxalic acid non-aqueous bath DOI:10.15199/40.2019.3.3

  1. Introduction It has recently been demonstrated that deep eutectic solvents (DES) can be used for the electrodeposition of metal coatings including: Zn, Ni, Cr, Al, etc. [2,7] or synthesis of nanostructures [6]. This analogues of ionic liquids (IL) can be formed from mixtures of quaternary ammonium salt (i.a. choline chloride (ChCl)) with hydrogen bond donor (i.a. ethylene glycol, urea, carboxylic acids and so on) [6]. What is more interesting, DES may also be successfully used for electropolishing of metals [3-5]. According to Abbott et al. [3], the biggest advantages of DES that give them an advantage over currently used sulphate baths for electropolishing are: (i) high current efficiencies, (ii) negligible gas evolution at the anode/bath interface, and (iii) the DES bath is benign and non-corrosive. Summing up the current information available in the literature, the process of formation and dissolution the passive layer occurring at the metal / non-aqueous bath interface is crucial for the metal dissolution mechanism and determines the final surface morphology - i.a. roughness [1]. On the other hand, a very large number of possible eutectic mixtures, gives a wide range of possibilities for finding a suitable environment for a selected type of steel. Therefore, in this article, the anodic treatment of 304 stainless steel in a new potential solution for electropolishing: a mixture of choline chloride and oxalic acid (1:1 molar ratio) was investigated by potentiodynamic polarization. The morphology, and corrosion resistance of 304 steel as a function of exposure time to NaCl solution were analyzed by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). 2. Materials and methods The 304 stainless steel (surface finish No. 2B - a smooth, moderately reflective cold-rolled annealed and pickled) was used as the Preliminary studies on the possibility of electropolishing of 304 alloy steel in a new n[...]

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