Izvorni znanstveni članak

Thermodynamic study of atmospheric corrosion seasonal kinetic, based on Sun photometer data

Delia-Gabriela Calinoiu ; Universitatea Politehnica Timisoara, Bv. Mihai Viteazu, No 1, 300222 Timisoara, Romania
Ioana Ionel ; Universitatea Politehnica Timisoara, Bv. Mihai Viteazu, No 1, 300222 Timisoara, Romania
Mirjana Ševaljević ; Technical College of Applied Science in Zrenjanin, Ul. Đorđa Stratimirovića 23, 23 000 Zrenjanin, Serbia
Milan Pavlović ; Technical Faculty "Mihajlo Pupin" in Zrenjanin of University in Novi Sad, Đure Đakovića bb, 23000 Zrenjanin, Serbia
Laszlo Makra ; University of Szeged, 6720 Szeged, Dugonics tér 13, Hungary
Ion Vetres ; Universitatea Politehnica Timisoara, Bv. Mihai Viteazu, No 1, 300222 Timisoara, Romania
Gavrila Trif-Tordai ; Universitatea Politehnica Timisoara, Bv. Mihai Viteazu, No 1, 300222 Timisoara, Romania

Sažetak

The atmospheric corrosion is a mechanical, technological, economic as well as an ecological problem, due to the enormous losses in corroded vessels material and machine material due to enhanced content of corroded material pollutants in environment. The results of the thermodynamic diagnostic study are given in this paper of the limited step in the water vapor corrosion kinetic based on the monitoring data for the seasonal water vapor pressure measured daily in Timisoara, by 2011, from March to December. Based on the seasonal values of the measured data, the seasonal diffusion rate constants the activation energies of the first chemical corrosion step are determined. The calculated seasonal water vapor chemical surface polarizations relative to the values of equilibrium entropies and also of the condensed water vapor on the solid surfaces are compared with the literature data of the possible products of chemical processes. The thermodynamic diagnostic study of the limited successive relaxation step in overall corrosion kinetic is carried out, based on the comparison of the molar water vapor couple relaxation work. The depolarization work is proportional to the depolarization rate constants of reactants and products activated successively in couple with water vapor concentrations depolarization energy, in the same time period: the electrochemical relaxation for the achievement of oxygen and hydrogen equilibrium in the seasonal activated corrosion cell, hydrogen depolarization energy and oxygen striping indicators standard potential. Data used to calculate the water vapor pressure in atmosphere are based on measurements accomplished by a sun photometer located at the Politechnica University of Timisoara, Romania (45,74 °N; 21,22 °E). The extraction of water vapor amount from sun photometer capacity relies on a measurement in the region of water vapor absorption at 940 nm. In order to apply the empirical models, the temperature, barometric pressure and humidity content have been taken from a weather station. One found that the experimental values of water vapor pressure, obtained using the sun photometer, are comparable with four other methods, and within, the experimental variations is characterized by a relative error of 2 %.

Ključne riječi

chemical/electrochemical equilibrium; corrosion; hydrogen over potential; indicator of reversible and irreversible process; Sun photometer; water vapour; water vapour couple kinetic

Hrčak ID:

120379

URI

https://hrcak.srce.hr/120379

Datum izdavanja:

26.4.2014.

Podaci na drugim jezicima: hrvatski

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