Rupičasta korozija zavarenih spojeva nehrđajućih čelika

undergraduate thesis

• Title (english): Pitting corrosion of stainless steel welded joints
• Author: Marko Grgić
• Mentor: Vinko Šimunović (mentor)
• Committee member: Zoran Kožuh (predsjednik povjerenstva)
• Committee member: Vinko Šimunović (član povjerenstva)
• Committee member: Zdenka Keran (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2020-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Visokolegirani korozijski postojani Cr-Ni celici nalaze svoju sve siru primjenu u brojnim industrijskim podrucjima, arhitekturi i gradjevinarstvu, medicini i dr., a jedno od znacajnijih podrucja njihove primjene je i izrada razlicitih zavarenih konstrukcija izloyenih morskom okolisu npr. u brodogradnji, off shore tehnici i sl..
Iako se ovi materijali zavaruju bez znacajnijih poteskoca ukoliko se uvazavaju njihove specificnosti poput npr. izrayene sklonosti deformacijama, kao posljedica unosa topline tijekom zavarivanja moze doci do znatnog smanjenja svojstava korozijske otpornosti sto u okolisu kakav je more i morska atmosfera moze dovesti do intenzivnih lokalnih korozijskih ostecenja u podrucjima zavarenih spojeva – zonama strukturnih i povrsinskih nehomogenosti.
U radu su prikazana osnovna svojstva pojedinih skupina Cr-Ni celika, posebnosti kada je u pitanju njihovo zavarivanje te su dani primjeri korozijskih ostecenja u podrucjima zavarenih spojeva uz prikaz mogucnosti njihovog izbjegavanja. Detaljnije je obradjena rupicasta korozija te je provedeno eksperimentalno ispitivanje prema normi ATM G 48 s ciljem utvrdjivanja korozijske otpornosti razlicitih vrsta austenitnih nehrdj0ajucih celika i utjecaja toplinskih oksida i naknadne kemijske obrade zavara.

Abstract (english)

Cr - Ni alloyed stainless steels are very corrosion resistant and are regularly used in industry,
architecture, civil engineering, medicine, but are also among the most used metals for welded
joint structures which are used in maritime conditions, such as salty water.
Although stainless steel can be welded without any problem, we have to consider that the heat
input by welding can change the steel properties and reduce the corrosion resistance, which can
be very harmful in aggressive conditions, such as salty sea water. These can lead to serious
corrosion of welded joints which are the least resistant because of inhomogeneities in
microstructure and on the surface.
The basic properties of groups of Cr-Ni steels are presented in work, especially when it comes
to their welding, and examples of corrosion damage in the welded joints are given, with the
possibilities of avoiding them. Pitting corrosion was treated in more detail and experimental
testing was performed according to ASTM G 48 standard in order to test corrosion resistance
of different types of austenitic steel and the effect of heat tints oxides and chemical post weld
treatment were investigated.

• Keywords: nehr]ajuci celici; zavarivanje; rupicasta korooyija
• Keywords (english): pitting corrosion; welding; stainless steel
• Language: croatian
• URN:NBN: urn:nbn:hr:235:281738
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-02-27 11:27:00