[en] Highlights: • A non-linear 3D FEA thermal model of a thick deposit processed by laser cladding process is provided. • The simulation accurately predicts the measured thermal history, the depths of the melt pool and the Heat Affected Zone. • The shift of the phase transformation points during heating stage due to high heating rates is analyzed. • Homogeneous macrostructure composed of a mixed microstructure observed by metallography is explained by the thermal history. In this study, a 3D thermal model of laser cladding by powder injection applied to Ti-6Al-4V is developed. The manufactured part is made of a Ti-6Al-4V substrate on which successive layers of laser melted powder are added, leading to a thick deposit. The computed temperature field and its time evolution are compared to experimental measurements. The temperature distribution in the substrate allows the prediction of the depths of the melt pool and the heat affected zone. Correlations between simulated thermal histories and the final microstructure in the thick deposit are established, leading to the enhancement of a dynamic shift of the critical transformation points due to high thermal rates during laser processing. The nature of the phases present within the deposit is discussed.