The Kinetics of the Austenite-Ferrite Phase Transformation of Fe-4Cr Alloy during Continuous Cooling
The massive transformation, austenite (γ) → ferrite (α), in Fe-4Cr alloy subjected to cooling from the high-temperature austenite down to room temperature at cooling rates of 75, 150, 330 K min-1 were experimentally investigated by means of high-resolution differential dilatometry. It is found that the onset transformation temperature and the overall transformation time decrease with increasing the cooling rate applied. Furthermore, by fitting the calculated transformed fraction according to developed phase-transformation model to the experimental data obtained by differential dilatometry, the kinetic parameters are obtained which show the activation energy for growth and the activation energy for nucleation are considerably different, this may be due to considerably different interfacial structure with the matrix for minute embryos and for the much larger growing particles.
Jianmin Zeng, Taosen Li, Shaojian Ma, Zhengyi Jiang and Daoguo Yang
L. F. Zhang et al., "The Kinetics of the Austenite-Ferrite Phase Transformation of Fe-4Cr Alloy during Continuous Cooling", Advanced Materials Research, Vols. 194-196, pp. 1203-1209, 2011