Microstructure-Sensitive Crystal Plasticity Modeling for Austenitic Steel and Nickel-Based Superalloy Under Isothermal Fatigue Loading

Abstract Intermittent mechanical loads combined with high temperatures appear during the operation of turbines in jet engines or power plants, which can lead to high-temperature fatigue thermomechanical fatigue. Since assessment properties is a complex and time-consuming process, it essential develop validated material models that are capable predicting behavior, thus allowing extrapolation experimental results into broader range conditions. To accomplish this, two representative volume elements (RVEs), mimicking typical microstructure single crystal Ni-based superalloys polycrystalline austenitic steels, respectively, introduced. With help these RVEs, temperature deformation-dependent internal stresses be taken account. In next step, phenomenological plasticity implemented parameterized for cyclic deformation materials. The RVE, constitutive model, parameters superalloy from former study. For steel, however, an inverse procedure has been used identify its based on several isothermal tests wide range. identified parameters, valid description behavior at different possible. most important conclusion comparison materials kinematic hardening, responsible shape hysteresis loops, entirely described by within superalloy, modeled scale-bridging approach. Hence, no additional terms hardening need introduced describe superalloy. contrast, Ohno–Wang model needs considered additionally obtain correct plasticity.