عنوان مقاله [English]
نویسنده [English]چکیده [English]
Nickel-based superalloys, due to their unique properties such as tensile strength, creep strength, fatigue strength as well as high temperature corrosion and oxidation resistance, have a special place in the oil and gas industry, space vehicles, submarines, reactors. , Military electric motors, chemical ships and heat exchanger tubes. Among the nickel base alloys, Inconel X-750, a hardened sediment alloy, was investigated under different heat treatment cycles. First, all samples were dissolved in the same size for 2 hours at constant temperature 1155 ± 5 °C. They were then cooled in the furnace at low cooling rates and then aged at constant temperature for 24 hours at four different temperatures of 600-705-760-845 °C. Microstructural studies by light and electron microscopy showed that both environmental and cooling conditions after solution and aging treatment affect morphology, volume fraction and particlesize of primary and secondary gamma prime. As the temperature of the aging process increases, the morphology of the γ' will shift from a spherical to a cubic state and become larger and decrease in volume fraction. The aging temperature also plays an important role in the formation of the PFZ area around the grain boundary and with the increase of the aging temperature the thickness of precipitate free zone increases.