Termodinamičko proučavanje sezonske kinetike atmosferske korozije, na osnovu fotometrijskog odred{stroke}ivanja tlaka vodene pare

Translated title of the contribution: Thermodynamic study of atmospheric corrosion seasonal kinetic, based on sun photometer data

Delia Gabriela Calinoiu, Ioana Ionel, Mirjana Ševaljević, Milan Pavlović, Laszlo Makra, Ion Vetres, Gavrila Trif-Tordai

Research output: Contribution to journalArticle

Abstract

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%.

Original languageUndefined/Unknown
Pages (from-to)283-290
Number of pages8
JournalTehnicki Vjesnik
Volume21
Issue number2
Publication statusPublished - Apr 2014

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Keywords

  • Chemical/electrochemical equilibrium
  • Corrosion
  • Hydrogen over potential
  • Indicator of reversible and irreversible process
  • Sun photometer
  • Water vapour
  • Water vapour couple kinetic

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Calinoiu, D. G., Ionel, I., Ševaljević, M., Pavlović, M., Makra, L., Vetres, I., & Trif-Tordai, G. (2014). Termodinamičko proučavanje sezonske kinetike atmosferske korozije, na osnovu fotometrijskog odred{stroke}ivanja tlaka vodene pare. Tehnicki Vjesnik, 21(2), 283-290.