Utjecaj fluorida na korozijsku stabilnost nehrđajućeg čelika

undergraduate thesis

• Title (english): The influence of fluorides on corrosion stability of stainless steel
• Author: Gabrijel Zubčić
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Suzana Sopčić (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-03, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Applied Chemistry

Abstract

Cilj ovog rada je bio ispitati korozijsku stabilnost nehrđajućeg čelika AISI 316L na jamičastu koroziju u otopini koja sadrži vrlo agresivne flouridne ione. Ispitivanja su provedena u umjetnoj slini uz različite koncentracije flouridnih iona (γ(NaF)=0,01 g dm^-3, 0,1 g dm^-3 i 1 g dm^-3) i dvije različite vrijednosti pH (pH= 4 i 6,5). Tehnike koje su korištene za praćenje korozijskog ponašanja nehrđajućeg čelika su ciklička polarizacija i elektrokemijska impedancijska spektroskopija. Iz dobivenih rezultata vidljivo je da nehrđajući čelik AISI 316L pokazuje sklonost prema nastanku jamičaste korozije u umjetnoj slini sa ali i bez dodatka flouridnih iona zbog prisutnosti kloridnih iona u tim otopinama. U otopinama sa nižom pH vrijednošću sklonost prema nastanku jamičaste korozije još je veća i ne dolazi do repasivacije površine nehrđajućeg čelika.

Abstract (english)

The goal of this work was to test corrosion stability of stainles steel AISI 316L towards pitting corrosion in a solution which contains highly agressive flouride ions. Tests were conducted in artifical saliva with different concentrations of flouride ions (γ(NaF)=0,01 g dm^-3, 0,1 g dm^-3 and 1 g dm^-3) and two different pH values (pH= 4 i 6,5). Techniques that were used to monitor corrosion behaviour of stainless steel were cyclic polarization and electrochemical impedance spectroscopy. From the obtained results it is clear that stainless steel AISI 316L demonstrates a tendency toward pitting corrosion in artifical saliva with but also without the addition of flouride ions because of the presence of chloride ions in these solutions. In solutions with lower pH values tendency toward pitting corrosion is even bigger and repassivation of the surface of the stainless steel does not occur.

• Keywords: korozijska stabilnost; nehrđajući čelik; jamičasta korozija; umjetna slina; ciklička polarizacija; elektrokemijska impedancijska spektroskopija
• Keywords (english): corrosion stability; stainless steel; pitting corrosion; artifical saliva; cyclic polarization; electrochemical impedance spectroscopy
• Language: croatian
• URN:NBN: urn:nbn:hr:149:500191
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Applied organic chemistry; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-06-23 13:39:11