Electrochemical study of carbon steel protection with a superhydrophobic coating under conditions of 100% humidity and the presence of corrosion stimulants in the air

100% humidity and the presence in the air of such corrosion stimulants as CO2, NH3 and H2S are characteristic of livestock buildings. Under these conditions, a surface phase film of moisture is formed on the surface of the metals in which the indicated micro-mixtures of air are dissolved and hydrated almost completely with the formation of NH4OH and acids H2CO3 and H2S. The potentiodynamic polarization method was used to study the corrosion and kinetics of electrode processes on steel with a superhydrophobic coating in a NaCl background solution (used to provide sufficient electrical conductivity) saturated in pairs with CO2 and NH3, NH3 and H2S. Similar studies were conducted with uncoated electrodes. Superhydrophobic coating was obtained on the basis of laser texturing of the surface with subsequent hydrophobization with fluoroxysilane (wetting angle 165±2°, rolling angle 3±1°). The influence of the duration of the exposure of the electrodes in solution (0,25…168 h) on the kinetics of electrode processes and the corrosion rate of steel is considered. In the presence of CO2 and NH3 dissolution products, the corrosion rate of an electrode with a superhydrophobic coating on the second and third days of exposure is about an order of magnitude, and on the fourth and seventh days it is more than an order of magnitude lower than without coating. During the entire time the electrodes are in solution, the anode process on the superhydrophobic electrode is inhibited compared to an unprotected electrode. The medium containing the dissolution products of NH3 and H2S is more aggressive than the previous solution. Therefore, the corrosion rate of the electrodes without coating and with a coating here is higher than in the latter one. The corrosion rate of electrodes with superhydrophobic coating in the study period is only 1,5…2,5 times lower than that of uncoated electrodes. During the first day of exposure, the anode process is inhibited, and in the next 144 hours, on the contrary, it is facilitated in comparison with an unprotected electrode. Taking into account the corrosivity of the chloride solution, the possible effect of the dissolution products of aggressive air micro-impurities in the absence of background salt was analyzed.

ANODIC PROCESSES DURING ELECTRODEPOSITION OF NICKEL, ITS ALLOYS AND COMPOSITE COATINGS

The results of investigations of the anodic processes of electrodeposition of nickel, nickel-boron alloy, composite coatings nickel-ultrafine diamond and nickel-cobalt-aluminum oxide are presented. It was shown that the oxidation of the boron-containing additive occurs at potentials much more positive than the oxidation potential of nickel, which means that oxidation of the boron compound is impossible under real conditions of electrodeposition. During the electrodeposition of CEC, the anode process proceeds without any complications and the dissolution of the anodes occurs in the same way as in nickel-plating electrolytes, and the composite additives of UDD and Al2O3 do not affect the anodic processes.

Application of Origin in Material Corrosion Experiment

By using the electrochemical methods of polarization curves and alternating-current impedance and drawing curves with Origin software as well as fitting and analyzing the data of the analytic experiments, the corrosion law of the carbon steel in stratum water containing CO2 at different temperatures is researched in this paper. The result shows that the material corrosion in the simulated stratum water containing saturated CO2 at different temperatures is active dissolution process and is mainly subjected to the activation control. The temperature rise increases the reaction rate of the reactant in the medium while promoting anode process and cathode process so as to increase the corrosion rate of the carbon steel. And, the auxo-action of the temperature to the cathode process is bigger than the anode process. The examples prove that the Origin software can conveniently draw the curves as well as rapidly and accurately analyze and fit the experiment data. The processing process is convenient and rapid, which can save much time than the manual calculation and works better than other professional mathematical analysis software because it does not need programming.