TENSILE TEST ON IN-SITU SOLIDIFIED NOTCHED SPECIMENS - EFFECTS OF TEMPERATURE HISTORY AND STRAIN-RATE ON THE HOT DUCTILITY OF NB AND NB-V MICROALLOYED STEELS
P. Deprez et al., TENSILE TEST ON IN-SITU SOLIDIFIED NOTCHED SPECIMENS - EFFECTS OF TEMPERATURE HISTORY AND STRAIN-RATE ON THE HOT DUCTILITY OF NB AND NB-V MICROALLOYED STEELS, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 168(1), 1993, pp. 17-22
Hot steel ductility in continuous casting processes is determined by t
ensile tests of notched cylindrical specimens which are obtained by me
lting and solidification and then tested after rate-controlled cooling
with a new specific device available for any standard test machine. H
ot ductility is proposed to be related to ultimate area reduction in t
he notched zone of the specimens. Experiments in the range of 700-1000
-degrees-C are achieved on two types of niobium-vanadium microalloyed
steels which only differ by their vanadium content. Ultimate area redu
ctions are determinate by using in situ solidified specimens and rehea
ted ones from room temperature, 10(-3) and 0.5 s-1 mean strain rate be
ing considered. The change of ultimate area reductions mainly depends
on austenitic grain size, segregation's distribution, dynamic precipit
ation of niobium-vanadium carbonitrides and so far the recrystallizati
on occurrence of austenite.