Strain rate and oxidation effects on crack initiation at 600 and 650 °C in a nickel-based superalloy

Maxime Perrais (1, 2) , Alexandre Seror (1) , A. Burteau (3) , Eric Andrieu (2) , Dominique Poquillon (2)

1 SNECMA Châtellerault [Châtellerault]
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 Turbomeca

Nickel-based superalloys are sensitive to an oxidation-assisted intergranular crack (OAIC) growth mechanism. Crack initiation during slow strain rate tensile tests is investigated at 600 and 650 °C, at different strain rates, with or without oxidation on a direct-aged material. A V-shaped sample geometry is used to promote damage initiation for a specific stress triaxiality. The critical mechanical loading paths inducing intergranular crack initiation as well as the effect of oxidation are discussed.

Mots clés: Ni-based superalloys; Direct aged alloy 718; Oxidation; Environment assisted cracking

Domaines: Mécanique des matériaux [physics.class-ph]

Maxime Perrais, Alexandre Seror, A. Burteau, Eric Andrieu, Dominique Poquillon. Strain rate and oxidation effects on crack initiation at 600 and 650 °C in a nickel-based superalloy. Materials at High Temperatures, 2016, 33 (3), pp.241-247. ⟨10.1080/09603409.2016.1169665⟩. ⟨hal-01755241⟩