Characterization of cyclic behavior, deformation mechanisms, and microstructural evolution of MarBN steels under high temperature conditions

Adil Benaarbia (1) , Xu Xu (2) , Wei Sun (3) , Adib Becker (3) , Steve Osgerby (4)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 Loughborough University
3 UON - University of Nottingham, UK
4 GE Power - General Electric Power

In this paper, the low cycle fatigue behaviour of MarBN steels at elevated temperatures is discussed. Four cyclic loading waveforms were applied to investigate both the mechanical and microstructural features. The mechanical results exhibit continuous cyclic softening and decelerated stress relaxation, recoverable viscoelasticity at both short and long time scales and irrecoverable viscoplastic mechanisms. Detailed microstructural characterisation was also conducted to investigate the rupture behaviour of the investigated steel. The microstructural findings indicate typical transgranular and ductile fracture behaviour, extensive sub-grain formation and structural refinement as well as significant decrease in hardness close to the fracture surface.

Mots clés: MarBN steel; Low cycle fatigue; High temperature viscoplasticity; Martensitic substructure; Sub-grain formation

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

Adil Benaarbia, Xu Xu, Wei Sun, Adib Becker, Steve Osgerby. Characterization of cyclic behavior, deformation mechanisms, and microstructural evolution of MarBN steels under high temperature conditions. International Journal of Fatigue, 2019, 131, pp.105270. ⟨10.1016/j.ijfatigue.2019.105270⟩. ⟨hal-02316198⟩