Creep curve modelling of Austenitic Steel 316LN

Abstract

Physical based creep models that elucidate the creep deformation behaviour with ongoing microstructural evolution can be a useful tool for the components life assessment as well as the design of improved materials, deployed at high temperature and pressure. In this research work, a creep model that is a combination of physical based model and CDM approach is employed to predict the creep curves of steel 316LN. The microstructure based variables those are different dislocation densities (mobile and forest) are the input parameters. The model provides a provision for the assessment of each microstructural variable, in each time step of the creep deformation. Consequently, other than creep curves, the model also demonstrates the evolution of dislocation density (mobile and forest), dislocation velocity, dislocation mobility and mean free path. Initial values of input parameters (various dislocation densities and mean free path) are obtained from the literature for initializing the model. It can be observed that the predicted creep curves are in reasonable agreement with experimental ones and the evolution of other involved parameters is discussed thoroughly.