Karakterizacija sočelnih zvarnih spojev na visokotrdnostnem nizkolegiranem jeklu S1100QL varjenih po postopku MAG

magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo

Anže Smolej (Author), Damjan Klobčar (Mentor), Andrej Skumavc (Co-mentor)

Abstract

Človeštvu so kovine oz. kovinske zlitine poznane že od železne dobe dalje. Dandanes jekla predstavljajo nepogrešljivo gradivo modernega strojništva ter gradbeništva in so zato predmet številnih raziskav in izboljšav. Vzporedno z razvojem jekel se razvijajo tudi postopki za njihovo spajanje. Najzahtevnejše nosilne konstrukcije so izdelane iz jekel, ki ob čim manjši lastni masi zagotavljajo visoke trdnosti. Jeklo S1100QL, z garantirano napetostjo tečenja 1100 MPa, zaradi specifične kemijske sestave, vročega valjanja in posebne toplotne obdelave zahteva visoko stopnjo reda med postopkom spajanja v neločljive celote - moderne jeklene konstrukcije. Magistrsko delo obravnava problematiko varivosti jekla S1100QL z uporabo obločnega varilnega postopka MAG. Vsi spoji so bili ovrednoteni z naslednjimi neporušnimi in porušnimi preiskavami: preiskava s penetranti, natezni in upogibni preizkus, preizkus udarne žilavosti, meritev trdote, makro- in mikroskopija ter preizkus ugotavljanja hladne razpokljivosti. Izsledki magistrskega dela so pokazali, da je potrebno za kvaliteten zvarni spoj med varjenjem zagotavljati nizek vnos toplote ob ustrezni temperaturi predgrevanja in medvarkovni temperaturi. Prav tako smo s preizkusi ugotovili, da jeklo S1100QL tudi pri nizkih temperaturah predgrevanja ni dovzetno za nastanek hladnih razpok.

Keywords

magistrske naloge;visokotrdnostno nizkolegirano jeklo S1100QL;varivost;preizkus varilnega postopka;obločno varjenje MAG;zvarni spoj;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.09 - Master's Thesis
Organization:	UL FS - Faculty of Mechanical Engineering
Publisher:	[A. Smolej]
UDC:	669.14:621.791.75(043.2)
COBISS:	78593283
Views:	227
Downloads:	55
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Characterisation of gas metal arc welded butt joints of high-strength low-alloy S1100QL steel
Secondary abstract:	Mankind has been familiar with different metals and metal alloys since the Iron Age. Steels are indispensable material of modern mechanical and civil engineering. Parallel with the development of steels the joining technologies and procedures are also developed. The most demanding load-bearing constructions are made of steels which give us high strength at the lowest possible own weight. S1100QL steel, with a guaranteed yield strength of 1100 MPa, achieves its properties through proper chemical composition, hot rolling and specific heat treatment. Therefore, high rate of care is necessary when joining this steel into permanent joints - modern steel constructions. This master`s thesis deals with the problem of weldability of S1100QL steel using gas metal arc welding process. All welded joints have been characterised with following non-destructive and destructive methods: penetrant testing, tensile test, bend test, impact test, hardness testing, macro- and microscopy. Additionally, cold cracking sensitivity test has been done. The master`s thesis has shown that low heat input with correlation of proper preheating and interpass temperatures are necessary for high quality welded joints. Experimental results have also shown that S1100QL steel is not sensitive to cold crack appearance even at low preheating temperatures.
Secondary keywords:	master thesis;high-strength low-alloy S1100QL steel;weldability;welding procedure qualification record;gas metal arc welding;welded joint;
Type (COBISS):	Master's thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. Ljubljana, Fak. za strojništvo
Pages:	XXIV, 94 str.
ID:	13366727