Pojavni oblici korozijskog oštećivanja nehrđajućih čelika

master's thesis

• Title (english): Forms of stainless steel corrosion damages
• Author: Anja Klasiček
• Mentor: Vinko Šimunović (mentor)
• Committee member: Biserka Runje (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-07-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

U teorijskom dijelu rada najprije su opisani martenzitni, austenitni, feritni i dupleks nehrđajući čelici kao i njihova svojstva. Nadalje se opisuje njihova korozijska postojanost kao i lokalni korozijski fenomeni nehrđajućih čelika: rupičasta korozija, korozija u procjepu, napetosna korozija, interkristalna korozija i mikrobiološki poticana korozija.
Eksperimentalni dio rada sastoji se od dva dijela. U prvom dijelu opisana su ispitivanja provedena na uzorcima uzetih s dijela korozijski oštećene konstrukcije pogona za preradu mlijeka. Ispitivanja su provedena s ciljem utvrđivanja uzroka pojave korozijskog oštećenja cijevi od nehrđajućeg austenitnog čelika te se zaključuje o mehanizmu korozije. U drugom dijelu opisano je ispitivanje na napetosnu koroziju dodatna tri uzorka od različitih vrsta nehrđajućeg čelika (austenitnog, feritnog i dupleks). Korozijsko ispitivanje u kipućoj otopini magnezijevog klorida provedeno je sa svrhom prikazivanja otpornosti različitih vrsta nehrđajućih čelika na napetosnu koroziju.

Abstract (english)

In the theoretical part of the paper, martensitic, austenitic, ferritic and duplex stainless steels as well as their properties are described. Further is described their corrosion resistance as well as the local corrosion phenomena of stainless steels: pitting, crevice corrosion, stress-corrosion, intergranular corrosion and microbiologically induced corrosion.
The experimental part of the paper consists of two parts. The first part describes the tests performed on samples taken from a part of the corrosion-damaged structure of the milk processing plant. The tests were carried out in order to determine the cause of corrosion damage of stainless austenitic steel pipes and to conclude on the mechanism of corrosion. The second part describes the stress corrosion test of an additional three samples of different types of stainless steel (austenitic, ferritic and duplex). Corrosion testing in boiling magnesium chloride solution was carried out for the purpose of demonstrating the resistance of different types of stainless steels to stress-corrosion.

• Keywords: nehrđajući čelici; lokalni korozijski fenomeni; napetosna korozija; korozijski zamor
• Keywords (english): stainless steels; local corrosion phenomena; stress corrosion; corrosion fatigue
• Language: croatian
• URN:NBN: urn:nbn:hr:235:655983
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-07-06 17:10:00