par Caruso, Matteo ;Verboomen, Hector ;Godet, Stéphane
Référence Diffusion and defect data, solid state data. Part B, Solid state phenomena, 172-174, page (922-927)
Publication Publié, 2011
Article révisé par les pairs
Résumé : The eutectoid transformation of austenite can occur cooperatively (pearlite transformation) or by means of a non-cooperative mode (Divorced Eutectoid Transformation). In the cooperative mode, ferrite and cementite grow together, leading to the typical lamellar microstructure of pearlite. In the non-cooperative mode, spheroidal cementite particles grow directly from the undissolved carbides in the austenite phase. The transformation product is a fully spheroidized microstructure. In this study, the parameters promoting the occurrence of DET in a hypereutectoid steel (austenitization temperature, cooling rate, presence of proeutectoid cementite in the initial microstructure) were investigated. It is shown that low undercooling levels and a homogenous distribution of fine carbides in the austenite promote the DET over the lamellar transformation mode. The spheroidized microstructures produced by DET lead to larger ductilities comparing to those obtained by the lamellar transformation mode. © (2011) Trans Tech Publications.