Influences of solution cooling on microstructures, mechanical properties and hot corrosion resistance of a nickel-based superalloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2019-02, Vol.746, p.372-383
• Main Authors: He, Dao-Guang, Lin, Y.C., Tang, Yi, Li, Ling, Chen, Jian, Chen, Ming-Song, Chen, Xiao-Min
• Format: Article
• Language: English
• Subjects: Air conditioning; Cooling; Corrosion resistance; Elongation; Grain boundaries; Hot corrosion; Mechanical properties; Microhardness; Microstructures; Nickel; Nickel aluminides; Nickel base alloys; Oxidation; Precipitates; Solution cooling; Sulfidation; Superalloy; Superalloys; Ultimate tensile strength
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2019.01.015

The influences of solution cooling on the microstructures, mechanical properties and hot corrosion resistance of a nickel-based superalloy are researched. It is found that the mechanical properties and hot corrosion resistance are greatly influenced by the solution cooling methods including furnace-cooling (FC), water-cooling (WC) and air-cooling (AC). For the FC superalloy, large amount of coarse γ′′ (Ni3Nb) and γ′ (Ni3Al) phases precipitate from the matrix, and δ (Ni3Nb) phase preferentially precipitates on grain boundaries. Besides, compared with the WC and AC superalloys, the ultimate tensile strength, yield strength and micro-hardness of the FC superalloy are higher, but the elongation to fracture is lower. Additionally, the hot corrosion behavior can be well described by the sulfidation-oxidation model and the alkaline-base melting model. Furthermore, the FC superalloy has the best hot corrosion resistance among the three solution cooled superalloys,