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

Fe-33Mn-xC (x = 0,03,0.6,0.8, 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 Considere's criterion even at high strain rates. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.