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Hot ductility studies have been performed on C-Mn and C-Mn-Nb steels with an approach to simulate the effect of cooling conditions experienced by steel in secondary cooling zone during continuous casting. Thermal oscillations prior to tensile straining deteriorate hot ductility of steel by deepening and widening the hot ductility trough. C-Mn steels are found to exhibit ductility troughs in three distinct zones whereas C-Mn-Nb steel shows drop in ductility only at low temperature in the vicinity of ferrite transformation temperatures. Start of ferrite transformation in steels causes yield ratio to increase while work hardening rates and strength coefficient decrease with decrease in test temperature in presence of thermal oscillation prior to tensile testing. Inhibition of recrystallization due to build-up of AlN particles along with the presence of MnS particles in structure and low work hardening rates causes embrittlement of steel in austenitic range. Alloying elements enhancing work hardening rates in austenitic range can be promoted to improve hot ductility. The presence of low melting phase saturated with impurities along the austenitic grain boundaries causes intergranular fracture at high temperature in C-Mn steels.

Metals with a fine-grained microstructure have exceptional mechanical properties. Severe plastic deformation (SPD) is one of the most successful ways to fabricate ultrafine-grained (UFG) and nanostructured (NC) materials. Most of the SPD techniques employ very low processing speeds. However, the lowest steady-state grain size which can be obtained by SPD is considered to be inversely proportional with the strain rate at which the severe deformation is imposed. In order to overcome this limitation, methods operating at higher rates have been envisaged and used to study the fragmentation process and the properties of the obtained materials. However, almost none of these methods, employ hydrostatic pressures which are needed to prevent the material from failing at high deformation strains. As such, their applicability is limited to materials with a high intrinsic ductility. Additionally, in some methods the microstructural changes are limited to the surface layers of the material. To circumvent these restrictions, a novel facility has been designed and developed which deforms the material at high strain rate under high hydrostatic pressures. Using the facility, commercially pure aluminum was processed and analysis of the deformed material was performed. The microstructure evolution in this material was compared with that observed in static high pressure torsion (HPT) processed material.