Influence of Pearlite Morphology and Heating Rate on the Kinetics of Continuously Heated Austenite Formation in a Eutectoid Steel

A model that describes pearlite-to-austenite transformation during continuous heating in a eutectoid steel has been developed. The influence of structure parameters, such as interlamellar spacing and edge length of pearlite colonies, and heating rate on the austenite formation kinetics has been experimentally studied and considered in the modeling. It has been found that the kinetics of austenite formation is slower the coarser the initial pearlite microstructure and the higher the heating rate. Moreover, both start and finish temperatures of the transformation slightly increase as heating rate does, but finish temperatures are more sensitive to that parameter. A good agreement (accuracy higher than 90% in square correlation factor) between experimental and predicted values has been found. ---------------------------------------------------------------------------------------------------------------------------------------F.G. CABALLERO, Post-doctoral Research Assistant, and C. GARCÍA DE ANDRÉS, Senior Research Scientist, are with the Department of Physical Metallurgy, Centro Nacional de Investigaciones Metalúrgicas (CENIM), CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid, Spain. C. CAPDEVILA, Post-doctoral Research Assistant, with the Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK