Fracture experiments in a high-strength ductile steel (2.3Ni-1.3Cr-0.17C) were conducted under static and dynamic loading conditions in a three-point bend and a one-point bend configurations. A qualitative description of the influence of loading rate on the microscopic features of the fracture surfaces and their role in the fracture initiation process was considered. The fracture surfaces consist of tunneled region and shear lips. The size of the shear lips increases with increasing loading rate and is characterized by micro-voids and cell structures. The tunneled region consists of large voids and micro-voids that coalesce by impingement. At high loading rates, localized molten zones are observed at the tunnel-shear lip interface.

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