During conventional shot peening on metastable austenitic steels, martensitic transformation occurs in addition to plastic straining. In this work, the impact of a single spherical steel shot on a AISI 301LN steel was studied. The volume fraction of martensite, residual stresses in both phases were determined in the vicinity of the dent as a function of the shot velocity and diameter. An elasto-plastic two phase model that includes martensitic phase transformation was adapted to model mechanical and microstructural fields and implemented in Abaqus Explicit for the 2D simulation of a single shot impact. It was found, for instance, that the martensitic transformation takes place only under the dent and that martensite is in tension at the surface while austenite is in compression. Simulation results of stress levels showed a good agreement with experimental stresses determined by X-ray diffraction.

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: https://sam.ensam.eu Handle ID ABSTRACTThis study aims at the experimental and numerical analysis of TRIP780 steel after conventional shot peening. TRIP steels exhibit a multiphase microstructure with martensitic transformation of the retained austenite during shot peening. In-depth experimental analysis are carried out with microhardness and X-ray diffraction. Residual stresses profiles are determined in the pseudo-ferritic phases (α + α′) and in the retained austenite γ. A representative finite element model of shot peening with a material behavior law describing the multiphase microstructure and the martensitic phase transformation during loading is proposed. The results are compared to experimental data and the effect of martensitic transformation is numerically investigated.

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