Mikrostrukturne značajke zavarenih spojeva Cr-Ni čelika zavarenih AC MIG postupkom

master's thesis

• Title (english): Microstructural characteristics of Cr-Ni welds welded with AC MIG process
• Author: Bruno Bauer
• Mentor: Ivica Garašić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-12-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

U ovom je radu obrađena problematika zavarivanja visokolegiranih nehrđajućih čelika. Svrha
rada je odrediti prikladne parametre za zavarivanje visokolegiranih nehrđajućih čelika, kojima
se postiže željena mikrostruktura i geometrija zavarenog spoja. Rad se sastoji od dva dijela
teorijskog i eksperimentalnog.
U teorijskom dijelu opisane su vrste i razmatrana zavarljivost visokolegiranih nehrđajućih
čelika te kako sam proces zavarivanja utječe na mikrostrukturu i geometriju zavarenog spoja.
Dalje su promatrani prikladni postupci zavarivanja visokolegiranih nehrđajućih čelika. Za
zavarivanje tankih limova posebno su zanimljivi postupci s niskim unosom topline pa je stoga
analiziran AC MIG postupak koji pruža manji unos topline u materijal prilikom zavarivanja u
odnosu na konvencionalni MIG/MAG postupak.
U eksperimentalnom dijelu provedeno je automatizirano zavarivanje postupkom MIG/MAG s
primjenom istosmjerne i izmjenične električne struje. Zavarivanjem tankog lima od
visokolegiranog austenitnog nehrđajućeg čelika 1.4301 napravljeni su kutni zavareni spojevi.
Ispitivanje uzoraka sastojalo se od vizualne kontrole, analize makroizbrusaka, unosa topline i
geometrije zavara te mikroanalize. Primjenom izmjenične struje postignuta je drugačija
mikrostruktura i geometrija zavarenog spoja.

Abstract (english)

This paper deals with the problem of welding high-alloyed stainless steel. The purpose of this
work is to determine suitable parameters for welding high-alloyed stainless steels, which
achieve the desired microstructure and geometry of the welded joint. This paper consists of two
parts, theoretical and experimental.
In theoretical part, the sorts and weldability of high-alloyed stainless steels are described, and
how the welding process itself affects the microstructure and geometry of the welded joint.
Next, suitable procedures for welding high-alloy stainless steels were observed. Processes with
low heat input are particularly interesting for welding thin sheets, so the AC MIG process was
analyzed, which provides less heat input to the material during welding compared to the
conventional MIG/MAG process.
In the experimental part, automated MIG/MAG welding was performed using direct and
alternating current. Fillet welds were made by welding a thin sheet of high-alloyed austenitic
stainless steel 1.4301. Examination of samples consisted of visual and macro-section analysis,
heat input analysis, geometry analysis and microanalysis. By applying alternating current, a
different microstructure and geometry of the welded joint was achieved.

• Keywords: Austenitni čelik; zavarljivost; AC MIG; mikrostruktura
• Keywords (english): Austenic steel; weldability; AC MIG; microstructure
• Language: croatian
• URN:NBN: urn:nbn:hr:235:661775
• 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: Materials 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: 2022-12-10 09:49:57