| SM ISO690:2012|
GHITLEVICI, A.; MIKHAILOV, Valentin; MIKHAILYUK, Alexei; VERKHOTUROV, Anatoly; KOZYR, A.; KORNIENKO, L.; KONEVTSOV, Leonid. The possibilities and peculiarities electro-sparks alloying process as a method of forming anticorrosion coatings. In: Materials Science and Condensed Matter Physics. Editia 8, 12-16 septembrie 2016, Chişinău. Chişinău: Institutul de Fizică Aplicată, 2016, p. 353. ISBN 978-9975-9787-1-2.
|Materials Science and Condensed Matter Physics
Editia 8, 2016
Conferința "International Conference on Materials Science and Condensed Matter Physics" |
8-th Edition, Chişinău, Moldova, 12-16 septembrie 2016
The authors analyzing electro-physical and technological peculiarities of the electro-spark alloying (ESA) process, and also the possibilities of using of a wide range of materials as electrodes, including corrosion-resistant materials – show the process of forming of the qualitative and continuous coatings on the work areas of the machine parts. These coatings provide anti-corrosion protection of the machine parts in different aggressive environments. For example, at ESA of the OLC45 steel with electrodes of stainless steel (also, the version of coating deposition of the complexes: OLC45+Ni+Cr and OLC45+Ni+Cr has been studied) it was established that ESA provides anti-corrosion protection with an order of magnitude and higher. On the other hand, it is known that in many cases to ensure a continuity of coating of the 100%, it is very difficult. Meanwhile, in the Corrosion Laboratory of the Institute of the Physical Chemistry of the Academy of Sciences of the Russian Federation has been developed a method of cathodic modification with alloying titanium, chromium, stainless steel through which the electrochemical protection mechanism is achieved. In conclusion, this means that to attain this effect there is no need to ensure a 100% of continuity of coating. This allows considerable expansion of the areas of application of the ESA for anti-corrosion protection. As effective coatings, palladium (Pd), platinum (Pt), and in some cases Ni, Cu, W, Re, titanium carbide (TiC), chromium (Cr3C2) and molybdenum (Mo2C) can serve for such protection. As stated gist of this embodiment corrosion protection it is that when the metal coating is effective cathode, it can protect the base metal by electrochemical system by shifting the corrosion potential of the coating - Metal framework in the passive region, leading to a reduction in the corrosion current metal bases. Research has shown that ESA of titanium, stainless steel X18H10T, X25 with palladium and nickel enhance corrosion resistance by 1,5 - 5 times in sulfuric acid H2SO4 and sea water in solutions of 10 - 40% of sulfuric acid at 100 degrees Celsius. When electro-spark alloying titanium nickel in air under certain discharge energy is formed intermetallic Ti2Ni and its oxidized phase Ti4Ni2O, which provided resistance corrosion parts of titanium chloride-alkaline environments chlorine production, increasing equipment life 5-7 times. Similar coatings on titanium when tested in river and sea water corrosion resistance showed an increase by 1.5 - 2 orders of magnitude in terms of work in the mode of poorly soluble anodes. In this paper, the mechanism of this anti-corrosion protection and the prospects of expansion of the range of its practical application have been analyzed. Acknowledgments: This study was founded from Moldavian national project CSSDT 15.817.02.05A “Physico-chemical methods and engineering aspects of new materials and surfaces obtaining for multiscale technologies”