3. Metallurgical characterization
The failed blades were made of Inconel 718 which Saquinavir a Ni–Cr–Fe–Nb alloy fulfilling good mechanical properties such as high tensile and yield strength, significant rupture strengths and good resistance to mechanical fatigue.
3.1. Chemical composition and mechanical properties of blade material: Inconel 718
Chemical composition of the material UNS N07718 (Formerly Grade 718) complying with ASTM B637 requirements is prescribed in Table 1.
Chemical composition of UNS N07718 – ASTMB637.ElementComposition limits (%)Product (check) analysis variations, under min or over max, of the haploid specified limit of elementUNS N07718 (Formerly Grade 718)Carbon0.08 max0.01Manganese0.35 max0.03Silicon0.35 max0.03Phosphorus0.015 max0.005Chromium17.0–21.00.25Cobalt1.0 max0.03Molybdenum2.8–3.30.05 under min, 0.10 over maxColumbium (Nb) + tantalum4.75–5.500.15 under min, 0.20 over maxTitanium0.65–1.150.04 under min, 0.05 over maxAluminium0.20–0.800.05 under min, 0.10 over maxBoron0.006 max0.002IronRemainder…Copper0.30 max0.03Nickel50.0–55.00.35Full-size tableTable optionsView in workspaceDownload as CSV