On the identification of stress–strain relation by instrumented indentation with spherical indenter

The local stress–strain relations were characterized by instrumented indentation with spherical indenter. The results obtained by indentation with different indenter radii were compared with tensile stress–strain curves of two metastable austenitic stainless steels (grade A301 and A304) and analyzed using finite element model. A forward finite element analysis was also carried out with model material behavior (elastic–perfectly plastic, linear hardening, piece-wise linear hardening and power-law hardening). The limitations of identified stress–strain relations arising from the indenter shape, uneven contact and non-linear material behavior due to the deformation induced martensitic transformation are discussed.

► Instrumented indentation with spherical indenter. ► Identification of stress–strain relation using Tabor’s formulae. ► Limitations due to indenter shape, uneven contact and non-linear material behavior.