S. Sahay, Tata Research Development and Design Centre, Pune, India

Summary: Most of the industrial thermal processing operations have heating, isothermal soaking and cooling segments. In the present work it will be shown that replacing the isothermal soaking segment with controlled cyclic perturbations results in accelerated transformation kinetics in diverse phase transformations and varied materials systems. The dependence of transformation kinetics on the amplitude and frequency of the cyclic perturbations will be illustrated. The accelerated transformation kinetics under cyclic condition will be related to the functional relationship between heating rate and activation energy observed in several materials systems under isochronal condition. Furthermore, it will be shown that by designing and implementing cyclic treatments, as high as 15% productivity enhancement and 20% energy reduction can be achieved, while maintaining the product quality. Finally, the methodology of implementing this novel approach in the industrial heat treatment operations will be outlined and its limitations will be discussed.