Importance of crack-propagation-induced ɛ-martensite in strain-controlled low-cycle fatigue of high-Mn austenitic steel
Abstract
We investigated the roles of deformation-induced ɛ-martensitic transformation on strain-controlled low-cycle fatigue (LCF) through crack-propagation analysis involving a notching technique that used a focused ion beam (FIB) setup on Fe-30Mn-4Si-2Al austenitic steel. Using the FIB notch, we separated the microstructure evolution into macroscopic cyclic deformation-induced and crack-propagation-induced microstructures. Following this, we clarified the fatigue crack-propagation-induced ɛ-martensitic transformation to decelerate crack propagation at a total strain range of 2%, obtaining an extraordinary LCF life of 1.1 × 104 cycles.
- Publication:
-
Philosophical Magazine Letters
- Pub Date:
- June 2015
- DOI:
- 10.1080/09500839.2015.1052029
- Bibcode:
- 2015PMagL..95..303L
- Keywords:
-
- fatigue;
- low-cycle fatigue;
- high-Mn austenitic steel;
- reversible transformation-induced plasticity;
- focused ion beam;
- martensitic transformations