Microstructural study of an age hardenable martensitic steel deformed by equal channel angular pressing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 491; no. 1; pp. 172 - 176
• Main Authors: Mobarake, M. Iranpour, Nili-Ahmadabadi, M., Poorganji, B., Fatehi, A., Shirazi, H., Furuhara, T., Parsa, Habibi, Nedjad, S. Hossein
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2008; Elsevier
• Subjects: Cross-disciplinary physics: materials science; rheology; Equal channel angular pressing; Exact sciences and technology; Maraging steel; Martensite; Materials science; Other heat and thermomechanical treatments; Physics; Treatment of materials and its effects on microstructure and properties; Ultrafine grain; Equal channel angular pressing; Maraging steel; Ultrafine grain; Martensite; Maraging steels; High strain; Lattice distortion; Martensitic steels; SAED; Martensitic structure; ECAP; Dislocations; Dislocation density; Solution heat treatment; Transmission electron microscopy; Transition elements; Fine grain structure; Equal channel angular pressing;Maraging steel;Martensite;Ultrafine grain; Microstructure
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.02.034

Effect of large-strain deformation by equal channel angular pressing on the microstructure of a martensitic age hardenable steel, namely 18 Ni (3 0 0) maraging steel, was studied by means of transmission electron microscopy. Equal channel angular pressing was carried out on the solution-annealed steel up to four passes at room temperature through the route B c using a die with an inner angle of 90°. It was found that the initial martensitic structure of the solution-annealed steel evolves to a heterogeneously deformed structure consisting of ultrafine grains and lamellar dislocation cell blocks. Selected-area electron diffraction patterns revealed large orientation spread within the deformed structure. High density of dislocations and elastic lattice distortions were found in the deformed and aged microstructures.