[Back]

F. Imtiaz, E. Kozeschnik:
"Isothermal Austenite Decomposition in Low to Ultra-low Carbon Steels";
Poster: THERMEC 2009, Berlin, GERMANY; 2009-08-25 - 2009-08-29.

ISOTHERMAL AUSTENITE DECOMPOSITION IN LOW TO ULTRA-LOW CARBON STEELS

I. Farhan and E. Kozeschnik

Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11 / E308, 1040 Vienna, Austria
(E mail: farhan.imtiaz+e308@tuwien.ac.at )

The austenite to ferrite transformation is studied experimentally and theoretically in low to ultra-low carbon steels with a carbon variation from 0.004 to 0.111 wt%. After austenitization at 950 °C, the samples are quenched to isothermal transformation temperature at quenching rates between 1600 and 1 K/s in a high speed quenching dilatometer. The isothermal holding temperatures are chosen between 905 and 740°C such that the transformation occurs either within the austenite/ferrite two-phase region or below in the ferrite one-phase field. The progress of ferrite formation is recorded by the length change of the samples. The experimental investigations are complemented by computer simulations of the austenite to ferrite phase transformation using the software packages DICTRA and MatCalc. The experimental and computational results are compared for transformation start temperature, effect of grain size, variation of carbon content and the role of interfacial energy.