Sabri, KhierSi-Chaib, Mohamed OualiGaceb, Mohamed2021-02-092021-02-0920211547-7029DOI: 10.1007/s11668-020-01076-5https://link.springer.com/article/10.1007/s11668-020-01076-5https://dspace.univ-boumerdes.dz/handle/123456789/6305The purpose of this paper is to evaluate high-pressure turbine blades after a long-term thermal exposure in a land-based gas turbine. Emphasis is placed upon structure and composition of the various layers evolving, on the one hand, due to hot oxidation/corrosion attacks and, on the other hand, because of interdiffusion phenomena between the substrates and their protective coatings. This work therefore discusses the influence of γ′-Ni3 (Al, Ti) precipitates coarsening, needle σ-phase nucleation, and M23C6-Carbides formation on the hardness properties of blades. In addition, this assessment attempts to evaluate the influence of γ′-Ni3 (Al, Ti) orientation changes and crystallites size growth on the intrinsic degradation of GTD-111 and IN738LC substratesen(CC) GTD-111 superalloy(CC) IN738LC superalloyNiPtAl coatingVPS coatingNeedle r-phaseHot corrosion/oxidationArticle