<p>In present study, hot corrosion behavior of high-activity-low-temperature Pt-Al-thermal sprayed 7YSZ coated-gas turbine second-row blades made of Rene-80 Ni-based superalloy was evaluated. For this purpose, hot corrosion test was carried out after 10, 20, and 40 cycles (HT10, HT20, and HT40 samples) in Na₂SO₄ molten salt in air at 900&#xa0;°C. Then, the tensile test on hot corroded samples was performed at 850&#xa0;°C. The coating/substrate microstructure and the effect of interfacial evolution on tensile behavior were discussed. It was observed that the yield strength was first decreased after hot corrosion cycles (≈38 MPa) and then increased (≈82 MPa). However, tensile strength increased continuously (≈10 MPa). Additionally, elongation showed different trend. The highest rate of strain energy release was at the thermally grown oxide interface for all samples. Also, the strain energy release rate and the crack growth rate increased. On the other hand, in the substrate, the area fraction of γ′ phase increased (2.6%), and its average size decreased (134 nm). The nucleation and propagation of intergranular cracks and their linkage to the substrate micro-pores occurred in the substrate due to different carbides and η phase. The formation of η phase led to changes in strength and elongation and increase in the substrate diffusion zone thickness (12 μm).</p>