Συσχέτιση μαγνητικών ιδιοτήτων και μικροδομής σε χάλυβες

Παπαδοπούλου, Σοφία; Papadopoulou, Sofia

dc.contributor.author	Παπαδοπούλου, Σοφία	el
dc.contributor.author	Papadopoulou, Sofia	en
dc.date.accessioned	2016-04-14T09:48:22Z
dc.date.available	2016-04-14T09:48:22Z
dc.date.issued	2016-04-14
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/42398
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.9841
dc.rights	Αναφορά Δημιουργού-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nd/3.0/gr/	*
dc.subject	ΜΚΕ	el
dc.subject	Ηλεκτρικός χάλυβας	el
dc.subject	Μαγνητικές μέθοδοι	el
dc.title	Συσχέτιση μαγνητικών ιδιοτήτων και μικροδομής σε χάλυβες	el
heal.type	bachelorThesis
heal.classification	ΜΚΕ	el
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2015-07-20
heal.abstract	Με τη βόηθεια μη καταστρεπτικών μεθόδων, του μαγνητικού θορύβου Barkhausen και της μαγνητικήςδιαπερατότητας έγινε έλεγχος των παραμενουσών τάσεων και της αλλαγής της μικροδομής σε ηλεκτρικό μη προσανατολισμένο χάλυβα. Τα δοκίμια του τελευταίου είχαν υποστεί εφελκυσμό και κάμψη.	el
heal.abstract	For an accurate design of electrical machines, the magnetic properties of steel laminations used as magnetic cores need to be precisely estimated. However, the material’s behavior in the core is different from the one measured under standard conditions. The main reason appears to be the presence of mechanical strains resulting from indispensable manufacturing operations like punching and core assemblage. To account for this difference, an empirical factor is used until now, because the understanding and the modelling the complex magnetomechanical interactions in core materials are still open problems. The magnetic properties of steel sheets and strips used as magnetic cores in electrical machines are very sensitive to mechanical strains resulting from manufacturing operations. This study presents an experimental in situ characterization of a non-oriented electrical steel and dedicates to a better understanding of the magnetization mechanisms of the electrical steel in the presence of mechanical strains. The mechanical properties of the study material were determined under a monotonous uniaxial tensile test. Barkhausen noise and magnetic hysteresis measurements were performed on elastically and plastically strained unloaded specimens, showing a strong degradation of the magnetic properties as an effect of plastic strain. This effect is more pronounced for low and medium values of the magnetic field strength, corresponding to the reversible and irreversible motion of domain walls, which stands for the pinning effect of dislocations. The deformation stages are clearly identified by the magnetic parameters.	en
heal.advisorName	Χριστοφόρου, Ευάγγελος	el
heal.committeeMemberName	Φούρλαρης, Γεώργιος	el
heal.committeeMemberName	Παπαευθυμίου, Σπυρίδων	el
heal.committeeMemberName	Χριστοφόρου, Ευάγγελος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Μηχανικών Μεταλλείων Μεταλλουργών. Τομέας Μεταλλουργίας και Τεχνολογίας Υλικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	70 σ.	en
heal.fullTextAvailability	true