Current pulses alter the structure of steels: APMS conference
Channel: bhadeshia123
Date: 02/08/2013

A lecture given by Rongshan Qin, at the Adventures in the Physical Metallurgy of Steels (APMS) conference held in Cambridge University. Short electrical pulses are applied to dramatically modify the structure of steel. The presentation file can be downloaded from http://www.phase-trans.msm.cam.ac.uk/apms/
http://www.phase-trans.msm.cam.ac.uk/

Abstract

Pulsed electric current affects kinetic barrier in non-equilibrium processes and thermodynamic state in non-equilibrium systems. Application of the high density and short duration current pulses in steel processing enables the fabrication of novel microstructure and hence the new property. Our experimental observations have demonstrated the powerful and versatile effects of pulses on microstructure evolution in steels, e.g. pulse-induced grain coarsening, grain refinement, texture control, low temperature transformation and novel phase formation. This reveals significant potential in using electrical pulses to tailor the microstructure of steels. The preliminary theoretical understanding of the observed phenomena has been developed based on the thermodynamic consideration. Kinetic aspect of the effect of the pulses on microstructure transformation, however, is still in its very early stage and requires more attention.