A TEM investigation of the stepped bainite reaction in silicon steels

Papadimitriou, G; Fourlaris, G

dc.contributor.author	Papadimitriou, G	en
dc.contributor.author	Fourlaris, G	en
dc.date.accessioned	2014-03-01T01:47:06Z
dc.date.available	2014-03-01T01:47:06Z
dc.date.issued	1998	en
dc.identifier.issn	11554339	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25143
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-11644304508&partnerID=40&md5=fa531966dba6c1961ebcfd63eb18e369	en
dc.subject.other	Bainitic transformations	en
dc.subject.other	Crystal lattices	en
dc.subject.other	Crystal microstructure	en
dc.subject.other	Crystallography	en
dc.subject.other	Electron diffraction	en
dc.subject.other	Quenching	en
dc.subject.other	Silicon steel	en
dc.subject.other	Transmission electron microscopy	en
dc.subject.other	Shear mechanism	en
dc.subject.other	Bainite	en
dc.title	A TEM investigation of the stepped bainite reaction in silicon steels	en
heal.type	journalArticle	en
heal.publicationDate	1998	en
heal.abstract	The bainitic reaction in steels has been extensively studied, however it is still controversial whether it proceeds by a diffusional or a shear mechanism. In a previous investigation of the bainite reaction in a Fe-3.9Si-0.9C steel the transformation was considered to be the result of two competing elementary mechanisms, i.e., the shear transformation of the γ-iron lattice and the diffusion of interstitial carbon away from the transformation interface. According to this model, the transition from upper to lower bainite occurs when the rate of interstitial carbon traversing the γ/α interface becomes of the same order with the velocity of the shear front. This interpretation stipulates that the carbon content corresponding to the γ/α and To curves of austenite is critical. Using step quench experiments and determining the percentage of the residual austenite and its carbon content it was demonstrated that both Xγ/α and ẊTo contents of the austenite play an important role in the initiation of its decomposition and its incomplete transformation. In this paper, the microstructural and crystallographic characteristics of the bainite products obtained through the step quenching experiments are examined, using TEM and Electron diffraction. The results are compared to those obtained by the corresponding bainitic transformation in a single step. The obtained results clearly corroborate the aforementioned model of transformation, which necessitates both a shear mechanism of the iron lattice and a redistribution of carbon between the parent phase and its transformation products.	en
heal.journalName	Journal De Physique. IV : JP	en
dc.identifier.volume	7	en
dc.identifier.issue	5	en
dc.identifier.spage	C5	en
dc.identifier.epage	131-C5-133	en