1. Tensile deformation and fracture properties of a 14YWT nanostructured ferritic alloy.
- Author
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Alam, M.E., Pal, S., Fields, K., Maloy, S.A., Hoelzer, D.T., and Odette, G.R.
- Subjects
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IRON oxides , *TENSILE strength , *DEFORMATIONS (Mechanics) , *FRACTURE mechanics , *FERRITIC steel , *NANOSTRUCTURED materials synthesis , *BALL mills - Abstract
A new larger heat of a 14YWT nanostructured ferritic alloy (NFA), FCRD NFA-1, was synthesized by ball milling FeO and argon atomized Fe-14Cr-3W-0.4Ti-0.2Y (wt%) powders, followed by hot extrusion, annealing and cross rolling to produce an ≈10 mm-thick plate. NFA-1 contains a bimodal size distribution of pancake-shaped, mostly very fine scale, grains. The as-processed plate also contains a large population of microcracks running parallel to its broad surfaces. The small grains and large concentration of Y–Ti–O nano-oxides (NOs) result in high strength up to 800 °C. The uniform and total elongations range from ≈1–8%, and ≈10–24%, respectively. The strength decreases more rapidly above ≈400 °C and deformation transitions to largely viscoplastic creep by ≈600 °C. While the local fracture mechanism is generally ductile-dimple microvoid nucleation, growth and coalescence, perhaps the most notable feature of tensile deformation behavior of NFA-1 is the occurrence of periodic delamination, manifested as fissures on the fracture surfaces. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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