Intermediate temperature brittleness of Ni based superalloy Nimonic263

• Published in: Materials characterization Vol. 140; pp. 9 - 14
• Main Authors: Chung, Hee-Jeong, Huh, Joo-Youl, Jung, Woo-Sang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2018
• Subjects: BRITTLENESS; CORROSION; DEFORMATION; DUCTILITY; Ductility minimum; Gamma prime; HEAT RESISTING ALLOYS; Intermediate temperature brittleness (ITB); MATERIALS SCIENCE; Ni based superalloy; NICKEL ALLOYS; Precipitate; SCANNING ELECTRON MICROSCOPY; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0400-1000 K; TRANSMISSION ELECTRON MICROSCOPY; YIELD STRENGTH; Ni based superalloy; Intermediate temperature brittleness (ITB); Gamma prime; Precipitate; Ductility minimum
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2018.03.013

Ni based superalloy Nimonic263 offers excellent resistance to corrosion and high temperatures, and as such can be used under an A-USC environment, which has extremely high temperatures and high pressure. To investigate the intermediate temperature brittleness that is the temperature dependence of this alloy, the tensile test was carried out at a constant cross head speed of 1 mm/min in the temperature range of room temperature to 900 °C. As the temperature increased during the test, the constant yield strength decreased sharply at 800 °C while the ductility began to decrease from 500 °C and then recovered after showing a minimum value at 800 °C. The results of the OM, SEM and TEM observations indicate that the deformation mechanism changed from γ′ shearing to by-pass as the temperature increased, and the minimum ductility resulted from decohesion of the glide plane. •Intermediate temperature brittleness of Nimonic263 is investigated.•Deformation mechanism changes from γ′ shearing to by-pass with increasing temperature.•The minimum ductility is the result of glide plane decohesion.