Room-temperature blue brittleness of Fe-Mn-C austenitic steels

Fe-33Mn-xC (x = 0, 0.3, 0.6, 0.8, and 1.1 mass%) fully austenitic steels showed ductility degradation owing to dynamic strain aging (DSA). The elongation increased with increasing carbon concentration at a strain rate of 10^− 2 s^− 1. However, in the steels with carbon contents of 0.6%, 0.8%, and 1.1%, the elongation decreased with increasing carbon concentration at a strain rate of 10^− 5 s^− 1 where the DAS effect is distinct. Although all specimens showed ductile fracture with the formation of dimples, the work hardening-true stress relation of the Fe-33Mn-1.1C steel demonstrated fracture before satisfying Considère's criterion even at high strain rates.