Temperaturna histereza elektrodnog potencijala različitih pseudo-referentnih elektroda

master's thesis

• Title (english): Temeperature hysteresis of electrode potential of various pseudo-reference electrodes
• Author: Angela Kapitanović
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Ovaj rad bazira se na problemu iz prakse gdje je bilo potrebno primijeniti katodnu zaštitu kako bi se spriječila unutarnja korozija stjenka čeličnih bojlera. Cilj rada bio je odabrati odgovarajuću pseudo-referentnu elektrodu koja bi se mogla primijeniti u sustavu unutarnje katodne zaštite. U tu svrhu ispitano je ponašanje različitih metala, titana, legure krom-nikal, legure bakar-nikal te cinka kao potencijalnih pseudo-referentnih elektroda. Tijekom ispitivanja pratio se njihov korozijski potencijal u ovisnosti o temperaturi za raspon temperatura 20 °C - 80 °C. Snimane su temperaturne histereze odnosno promjena korozijskog potencijala u ovisnosti o temperaturi tijekom ciklusa zagrijavanja i hlađenja. Odabir odgovarajuće pseudo-referentne elektrode ovisi o reproducibilnosti rezultata i veličini temperaturne histereze korozijskog potencijala. Na temelju najmanje temperaturne histereze cink se pokazao najadekvatnijim odabirom za ove svrhe. Najveća razlika korozijskog potencijala tijekom ciklusa zagrijavanja i hlađenja uočena je kod titana, a značajnije rasipanje podataka u dobivenim rezultatima uočeno je za legure krom-nikal te bakar-nikal. Cink se u ispitivanim uvjetima kontinuirano otapa kao i čelik pa se analogno mijenjaju i korozijski potencijal cinka i ugljičnog čelika od kojeg su izrađene unutarnje stjenke bojlera. Ostali ispitivani metali se tijekom otapanja prevlače više ili manje postojanim oksidnim filmom.

Abstract (english)

This work is based on the practical problem where it was necessary to apply the cathodic protection to prevent the internal corrosion of steel boilers. The aim of the work was to choose the appropriate pseudo-reference electrode that could be applied in internal cathodic protection system. Metals which were tested for this purpose as pseudo-reference electrodes were titanium, chromium-nickel alloy, copper-nickel alloy and zinc. Their corrosion potential dependence on temperature was examined in temperature range 20 °C - 80 °C. In order to obtain corrosion potential temperature hysteresis, corrosion potential dependence on temperature was monitored during the cycle of heating and cooling. The selection of pseudo-reference electrode depends on the reproducibility of results and the magnitude of corrosion potential temperature hysteresis. Based on the smallest observed temperature hysteresis zinc was found the most adequate for this purpose. The biggest difference of corrosion potential during the cycle of heating and cooling was observed for titanium and the significant scattering of the data was observed for chromium-nickel alloy and copper-nickel alloy. In studied conditions zinc is continuously corroding, similar to steel, such that corrosion potentials of zinc and carbon steel, from which are made internal walls of the boilers, are changing in a similar fashion. Corrosion of other studied metals leads to their coverage with less or more stable oxide film.

• Keywords: korozija; katodna zaštita; korozijski potencijal; pseudo-referentna elektroda; temperaturna histereza
• Keywords (english): corrosion; cathodic protection; corrosion potential; pseudo-reference electrode; temperature hysteresis
• Language: croatian
• URN:NBN: urn:nbn:hr:149:455223
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-03-05 08:50:03