Analiza utjecaja zaštitnih plinova pri AC MIG navarivanju dupleks čelika

master's thesis

• Title (english): Analysis of shielding gas influence in AC MIG duplex steel overlay welding
• Author: Mislav Ćuže
• Mentor: Ivica Garašić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-07-18, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

U teorijskom dijelu ovoga diplomskog rada dan je pregled osnovnih gradacija dupleks čelika,
pri čemu je najveći fokus je na njihovom zavarivanju, stoga je detaljno objašnjena problematika
zavarivanja dupleks čelika, kao i utjecaj parametara od kojih je posebno naglašen utjecaj
zaštitnih plinova. Dodatno, eksperimentalni rad se temelji na primjeni novog i sve popularnijeg
modificiranog postupka zavarivanja, AC MIG postupka. Stoga je najprije detaljno objašnjen
princip rada AC MIG postupka, a zatim njegovi glavni parametri.
Eksperimentalni rad temelji se na navarivanju najpopularnijeg dupleks 2205 nehrđajućeg čelika
na običan konstrukcijski čelik, S355JR. Testira se učinak različitih EN omjera AC MIG
postupka i utjecaj dvije vrste zaštitnih plinova (Ar + CO2 i Ar + N2) na rezultate navarivanja.
Rezultati navarivanja su kvalitativno i kvantitativno opisani na temelju mikro i makroanalize te
su doneseni pravodobni zaključci. Dokazano je kako EN omjer i vrsta zaštitnog plina ima
značajan utjecaj na stabilnost električnog luka, geometriju zavara i omjere austenitne i feritne
faze u mikrostrukturi zavara. Na samome kraju su dane smjernice za daljnja istraživanja.

Abstract (english)

In the theoretical part of the thesis, an overview of the basic gradations of duplex steel is given,
with the main focus on their weldability. Therefore, the common weldability issues of duplex
stainless steel welding are explained in detail, as well as the influence of parameters, of which
the influence of shielding gases is particularly emphasized. Additionally, the experimental work
is based on the application of a new and increasingly popular modified welding process, the
AC MIG process. The working principle of the AC MIG process is therefore explained in detail,
followed by its main parameters.
The experimental work is based on bead on plate welding of the most popular duplex 2205
stainless steel to a common structural steel, S355JR. The effect of different EN ratios of the AC
MIG process and the influence of two types of shielding gases (Ar + CO2 and Ar + N2) on weld
bead geometry are tested. Furthermore, the results of welding are qualitatively and
quantitatively described on the basis of micro and macro analysis and the conclusions are
drawn. It has been proven that the EN ratio and the type of shielding gas have a significant
influence on the stability of the electric arc, the weld bead geometry and the ratio of the austenite
and ferrite phases in the microstructure of the weld. At the very end, guidelines for further
research are given.

• Keywords: Dupleks 2205; navarivanje; zavarivanje raznorodnih metala; AC MIG; zaštitni plin; EN omjer
• Keywords (english): Duplex 2205; bead on plate welding; dissimilar metal welding; AC MIG; shielding gas; EN ratio
• Language: croatian
• URN:NBN: urn:nbn:hr:235:974290
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering, Mechatronics and Robotics, Autonomous Systems; Course: Production 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: 2022-07-11 11:27:57