Effect of Microstructure on the Low-Cycle Fatigue Properties of a Fe–15Mn–10Cr–8Ni–4Si Austenitic Alloy

In the present study, the effect of the initial austenitic structure on the low-cycle fatigue (LCF) properties and ε-martensitic transformation (ε-MT) was studied in the Fe–15Mn–10Cr–8Ni–4Si seismic damping alloy under an axial strain control mode with total strain amplitude, Δε_t/2, of 0.01. The microstructures with various grain size and texture conditions were produced by warm rolling followed by annealing at temperatures that ranged from 600 to 900 °C. It was found that the increase in the austenitic grain size observed in the studied temperature interval generally does not affect martensitic transformation and the LCF resistance of the studied alloy. However, strong texture and substructure remaining in the alloy after low temperature annealing at T ≤ 700 °C inhibit strain-induced phase transformation and reduce fatigue resistance of the studied alloy. As a result, the alloy annealed at T ≥ 800 °C shows higher fatigue resistance than that one annealed at T ≤ 700 °C.