Characterization of the behavior of a turbine rotor steel by inverse analysis on the small punch test

The present work focuses on the application of the inverse methods on the small punch test (SPT) in order to predict the behavior of turbine rotor steel upon in-service loading. A numerical framework has been implemented in which the small punch test has been simulated by means of finite element analyses and compared with the experimental results in order to assess the material parameters. The comparison has been carried out relying on the load- displacement curve of the SPT. The material behavior has been represented through an elastic-plastic constitutive law and a micro-mechanical damage model to account for softening and material failure. The assessed material parameters have been employed in the simulation of the tensile test, showing a good approximation of the basic mechanical properties of the material.