Mapping of Low Cycle Fatigue Mechanisms at Elevated Temperatures for an Austenitic Stainless Steel

Mapping of low cycle fatigue mechanisms at elevated temperatures is attempted for a better understanding of the elevated temperature, low cycle fatigue behavior of an austenitic stainless steel. Results of strain-controlled, uniaxial low cycle fatigue tests on a solution-treated Type 310 stainless steel were used in the analysis. The experiments were performed at 15 temperatures that ranged from room temperature to 800°C and under four strain rate conditions that ranged from 6.7 × 10⁻³ s⁻¹ to 6.7 × 10⁻⁶ s⁻¹. Modes of variation, both in stress amplitude and in fatigue life, are classified and plotted against temperature-strain rate coordinates. By superposing the two maps, one can easily find the principal factors that govern the fatigue life for any given conditions of temperature and strain rate. The proposed idea of mapping is believed to have wide applicability (e.g., for selecting materials and predicting fatigue behavior under service conditions).