Effect of Nb–V microalloying on low-cycle fatigue property of Fe–Mn–Al–C austenitic steel

Abstract

The tensile and low-cycle fatigue properties of Fe–Mn–Al–C austenitic steels without and with Nb–V microalloying are analyzed comparatively. The Nb–V microalloyed Fe–Mn–Al–C steel shows higher strength and lower elongation. The cyclic deformation behavior is noted as continuous cyclic softening. The fatigue life of the Nb–V microalloyed steel is higher at total strain amplitudes of 0.4% and 0.6%, but lower at 0.8% than that of the non-microalloyed one. The microstructures of the steels after fatigue test show parallel deformation bands, which are composed of planar dislocations. The precipitation of (Nb,V)C has a positive influence on improving the fatigue life compared with the κ-carbides.