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Документ Study of anode processes during development of the new complex thiocarbamide-citrate copper plating electrolyte(Технологический центр, 2018) Smirnova, Olha; Pilipenko, Alexei; Pancheva, Hanna; Zhelavskyi, Alexei; Rutkovska, KaterynaThe kinetics of anodic reactions occurring on copper in thiocarbamide-citrate solutions was studied. Thiocarbamide forms stable copper (I) complexes of the cationic type with a coordination number equal to unity. Citric acid ensures acid pH value of electrolyte and causes active dissolution of copper under conditions of anode polarization. The joint presence of CS(NH₂)₂ and C₆H₈O₇ in the solution contributes to the copper electrode activation under conditions of anodic polarization. Increasing the concentration of thiocarbamide leads to a drastic shift of copper dissolution potentials towards the region of negative values. Study of the kinetics of anodic behavior of copper by acquiring the voltammograms revealed the nature of the limiting stage of reaction. It is shown that the process of dissolution in a thiocarbamide-citrate electrolyte is controlled by the diffusion phase. This is confirmed by the results of graphical processing of polarization dependences in coordinates η–lg(1–ja/jd). An increase in υр within 5‒100 mV·s⁻¹ causes an increase in jd from 2.2 to 12.0 mА·cm⁻², which indicates diffusion control over the process. The process of copper dissolution proceeds under stationary mode with uniform etching of intragrain boundaries and volume of the metal's grain.Документ Study into the influence of concentration of ions of chlorine and temperature of circulating water on the corrosion stability of carbon steel and cast iron(Технологический центр, 2017) Pancheva, Hanna; Reznichenko, Ganna; Miroshnichenko, Nataliya; Sincheskul, Alexander; Pilipenko, Alexei; Loboichenko, ValentynaThe impact of the chloride ions concentration and the temperature of the circulating water on the process of corrosion destruction of carbon steel and cast iron has been investigated. It has been shown that an increase in the concentration of chloride ions causes a shift in the values of the stationary potentials of steel and cast iron to the region of negative values and reduces the passive state of these alloys. This leads to an increase in the corrosion rate of St.3 steel and CI 18-36 cast iron. The results of electrochemical studies have shown that the more reliable protective films are formed on steel than on cast iron. The limiting concentration of NaCl, at which reliable operation of equipment made from these alloys is possible, depends on the pH of the solution. At pH=7, it is about 1.2 g l⁻¹, which is about an order of magnitude less than at pH=12. When the circulating water temperature rises, the corrosion rate of steel and cast iron increases. The stationary potentials of steel and cast iron are shifted to the negative range, and the polarization of the anode process decreases. Corrosion process is limited by the rate of oxygen supply to the cathode areas.