Phase-based constitutive modeling and experimental study for dynamic mechanical behavior of martensitic stainless steel under high strain rate in a thermal cycle

Abstract

The material of turbine blades undergoes a complete thermal cycle in creep-feed grinding. The flow stress in the cycle has a significant effect on the residual stress, microtopography, and surface integrity. This study presents a phase-based constitutive model for describing the dynamic mechanical behavior of martensitic stainless steel in a complete thermal cycle. The complete tests were conducted by using thermal compressive deformation via Split Hopkinson Pressure Bar and Gleeble 3500, with temperature ranging from 20°C to 1000°C, and strain rate ranging from 0.001s−1 to 16,000s−1. Phase transformation kinetics was involved for the dual-phase region, and a modified Johnson–Cook model was employed to determine the dynamic mechanical behavior of single phase. The prediction of the phase-based model correlates well with the experimental data on stress–strain curves. The flow stress is demonstrated to form a loop in a complete thermal cycle, and the results indicated that the temperature history must be considered in the evolution of flow stress in terms of strain, strain rate, and temperature.