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	2014-03-01T01:46:21Z
dc.date.available	2014-03-01T01:46:21Z
dc.date.issued	1997	en
dc.identifier.issn	1155-4339	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/24888
dc.subject.classification	Physics, Multidisciplinary	en
dc.title	A TEM investigation of the stepped bainite reaction in silicon steels	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1997	en
heal.abstract	The bainitic reaction in steels has been extensively studied, however it is still controversial whether it proceeds bpa 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 gamma-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 gamma/alpha interface becomes of the same order with the velocity of the shear front. This interpretation stipulates that the carbon content corresponding to the gamma/alpha and T-o 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 X-gamma/alpha, and X-To contents of 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.publisher	E D P SCIENCES	en
heal.journalName	JOURNAL DE PHYSIQUE IV	en
dc.identifier.isi	ISI:000072520300021	en
dc.identifier.volume	7	en
dc.identifier.issue	C5	en
dc.identifier.spage	131	en
dc.identifier.epage	136	en