Hot Ductility of High Carbon Steel Produced by CSP

Hot ductility of a high carbon steel 65Mn produced by CSP (Compact Strip Production) was tested on Gleeble-3500 simulator. Results show that the great reduction of hot ductility occurred between 700°C900°C. This is resulted from the formation of ferrite allotriomorphs along prior austenite grain boundaries and aluminum nitride precipitation along and near austenite grain boundaries. In order to prevent from surface cracking on thin slabs, it is suggested that the unbending temperature should be controlled above 950°C.

Three-Dimensional Observation and Growth Kinetics of Proeutectoid Ferrite Formed at Austenite Grain Boundary in a Low Carbon Microalloyed Steel

Three-dimensional observations of proeutectoid ferrite formed at grain boundary in an Fe-0.09%C-1.48%Mn vanadium microalloyed alloy was revealed by techniques of serial sectioning along with computer-aided reconstruction. The ferrite allotriomorphs nucleated at grain boundary edges were approximately prolate ellipsoids. Not all the ferrite allotriomorphs formed at grain boundary faces were oblate ellipsoids. The growth kinetics of ferrite allotriomorphs nucleated at grain boundary edges was greater than that of ferrite allotriomorphs nucleated at grain boundary faces.