Utjecaj temperature na brzinu korozije višefaznih konstrukcijskih čelika

master's thesis

• Title (english): The influence of temperature on the corrosion rate of multiphase structural steels
• Author: Boris Maltar
• Mentor: Anita Begić Hadžipašić (mentor)
• Committee member: Zoran Glavaš (predsjednik povjerenstva)
• Committee member: Anita Begić Hadžipašić (član povjerenstva)
• Committee member: Natalija Dolić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2015-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy; Process Metallurgy

Abstract

Temperatura je vrlo utjecajan činitelj koji utječe na pojavu i brzinu razvoja korozije kod svih
metala koji su skloni koroziji, pa time i kod modernih višefaznih konstrukcijskih čelika
(TRIP-čelika). U radu je proučavana elektrokemijska korozija modernih višefaznih
konstrukcijskih čelika u kiselom mediju, pri povišenim temperaturama. Provedena istraţivanja
i prikazani rezultati pokazuju da je funkcionalna ovisnost razvoja korozije i navedenih
utjecajnih činitelja direktna i jaka.
Metodom potenciodinamičke polarizacije metala i elektrokemijskom impedancijskom
spektroskopijom izmeĎu tri vrste višefaznih TRIP-čelika različitih kemijskih sastava ispitanih
u kiselom mediju pri temperaturi od 20°C korozijski otpornijim se pokazao uzorak K, dok se
pri višim temperaturama pokazao korozijski otpornijim uzorak VA. O tome svjedoče manji
iznosi brzine korozije i veće vrijednosti otpora prijenosu naboja. TakoĎer, većoj korozijskoj
otpornosti uzorka VA pridonosi povoljnija mikrostruktura s više zaostalog austenita i
drugačiji koncept očvršćavanja, koji su posljedica različitog kemijskog sastava.

Abstract (english)

Temperature is a very influential factor affecting the occurrence and speed of development of
corrosion of all metals that are prone to corrosion, and therefore also in modern multiphase
structural steels (TRIP-steels). In this paper, the electrochemical corrosion of modern multiphase structural steels in an acidic environment at higher temperatures was studied. The
conducted investigations and the given results show that the functional dependence between
the corrosion rate and mentioned influential factors is direct and strong.
By method of potentiodynamic polarization and electrochemical impedance spectroscopy
among three multiphase TRIP-steels examined in acidic medium at a temperature of 20°C,
sample K showed a higher corrosion resistance, whereas at higher temperatures sample VA
showed higher corrosion resistance. This is evidenced by smaller amounts of corrosion rate
and higher values of charge transfer resistance. Also, to better corrosion resistance of the
sample VA contributes a favorable microstructure with more residual austenite and a different
strengthening concept as consequence of different chemical composition.

• Keywords: TRIP-čelik; elektrokemijska korozija; brzina korozije; impedancija; temperatura
• Keywords (english): TRIP-steel; electrochemical corrosion; corrosion rate; impedance; temperature
• Language: croatian
• URN:NBN: urn:nbn:hr:115:793239
• Study programme: Title: Graduate study program Metallurgy; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka metalurgije (magistar/magistra inženjer/inženjerka metalurgije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2015-10-15 09:02:36