Ispitivanje alatnog čelika X19NiCrMo4 na otpornost prema lokalnoj koroziji u različitim medijima

master's thesis

• Title (english): Testing of X19NiCrMo4 tool steel on resistance to local corrosion in different media
• Author: Petra Brajenić
• Mentor: Anita Begić Hadžipašić (mentor)
• Mentor: Sandra Brajčinović (pomoć pri izradi, neposredni voditelj)
• Committee member: Ivan Jandrlić (predsjednik povjerenstva)
• Committee member: Anita Begić Hadžipašić (član povjerenstva)
• Committee member: Stjepan Kožuh (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2021-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy

Abstract

U ovom radu provedeno je ispitivanje otpornosti alatnog čelika X19NiCrMo4 prema lokalnoj
koroziji elektrokemijskim i metalografskim metodama. Provedena je ciklička anodna
polarizacija navedenog čelika u različitim medijima u svrhu definiranja parametara lokalne
korozije. Ispitivanje se provodilo u četiri medija: 3,5 % NaCl, umjetna kiša, otopina emulzije
Lenox Band-Ade i vode te voda.
Elektrokemijska ispitivanja pokazala su kako je alatni čelik oznake X19NiCrMo4 najotporniji
prema lokalnoj koroziji u mediju emulzije Lenox Band-Ade, dok je najpodložniji lokalnoj
koroziji u mediju 3,5 % NaCl. Naime, jedino u kloridnom mediju je došlo do pojave pitting
korozije pri čemu je registriran piting potencijal, dok u ostalim medijima u referentnom
intervalu elektrodnog potencijala nije zabilježena pojava piting lokalne korozije.
Rezultate elektrokemijskih ispitivanja potvrdila su metalografska ispitivanja gdje se uočava
kako je cijela površina čelika nakon ispitivanja u mediju 3,5 % NaCl prekrivena korozijskim
produktima, dok je nakon ispitivanja u mediju emulzije Lenox Band-Ade površina čelika ista
kao i prije ispitivanja.

Abstract (english)

In this paper, the resistance of tool steel X19NiCrMo4 to local corrosion by electrochemical
and metallographic methods was tested. Cyclic anodic polarization of said steel in different
media was performed in order to define local corrosion parameters. The test was performed in
four media: 3.5% NaCl, artificial rain, water solution of Lenox Band-Ade emulsion and water.
Electrochemical tests have shown that X19NiCrMo4 tool steel is the most resistant to local
corrosion in water solution of Lenox Band-Ade emulsion medium, while it is most susceptible
to local corrosion in 3.5% NaCl medium. Namely, pitting corrosion occurred only in the
chloride medium and pitting potential was registered, while in other media, the occurrence of
pitting local corrosion was not recorded in the reference interval of the electrode potential.
The results of electrochemical tests were confirmed by metallographic tests where it is
observed that the entire steel surface after testing in 3.5% NaCl medium is covered with
corrosion products, while after testing in water solution of Lenox Band-Ade emulsion
medium the steel surface is the same as before testing.

• Keywords: lokalna korozija; piting potencijal; alatni čelik; mikrostruktura
• Keywords (english): local corrosion; pitting potential; tool steel; microstructure
• Language: croatian
• URN:NBN: urn:nbn:hr:115:824096
• 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: 2021-10-06 10:13:06