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Abstract
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Cold rolling and annealing of homogenized Fe–Ni–Mn–Mo–Ti–Cr maraging steels resulted in
the formation of submicrocrystalline Fe2(Mo,Ti) Laves phase particles. Optical and scanning
electron microscopy, X-ray diffraction, tensile and hardness tests were used to study the
microstructure, aging behavior and mechanical properties of the annealed steels. The
annealed microstructures showed age hardenability during subsequent isothermal aging at
753 K. Ultrahigh fracture stress but poor tensile ductility was obtained after substantial age
hardening in the specimens with 2% and 4% chromium. Increasing chromium addition up to
6% toughened the aged microstructure at the expense of the fracture stress by increasing the
volume fraction of retained austenite. The Laves phase particles acted as crack nucleation
sites during tensile deformation.
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