Litu Huo , Tao Ma , Weimin Gao , Yungang Li , Jianxin Gao
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引用次数: 0
Abstract
To develop high-strength, low-density steels applicable for automotive field, the study systematically investigated Fe-28Mn-10Al-C-0.5Nb steel after aging at 450 °C-550 °C in terms of its microstructure evolution, mechanical properties, and deformation and strengthening mechanisms. Electron backscatter diffraction (EBSD) method served for examining the austenite grain morphology and the orientation of annealing twins at different aging temperatures. Transmission electron microscopy (TEM) served for elucidating the precipitation behavior and spatial distribution of NbC, κ-carbides, and other secondary phases. Furthermore, the deformation mechanisms under different tensile strains were explored using TEM and EBSD, with particular attention to the evolution of dislocations and other substructures in the deformed specimens. Quantitative evaluation was conducted on the yield strength variation under varying strengthening mechanisms through theoretical modeling. According to relevant results, with rising aging temperature, the finely dispersed spherical κ-carbides gradually transform into a uniformly distributed rectangular morphology. The strength and toughness of the experimental steel both increase with aging temperature, and the steel aged at 500 °C exhibits an outstanding overall property, with a tensile strength of 1199 MPa and an elongation of 37 %. Planar dislocation slip is the primary deformation mode, and the favorable strength-ductility balance results from the microband-induced plasticity. Calculations confirm dislocation strengthening as the primary strengthening mechanism in the experimental steel.
期刊介绍:
Materials and Design is a multi-disciplinary journal that publishes original research reports, review articles, and express communications. The journal focuses on studying the structure and properties of inorganic and organic materials, advancements in synthesis, processing, characterization, and testing, the design of materials and engineering systems, and their applications in technology. It aims to bring together various aspects of materials science, engineering, physics, and chemistry.
The journal explores themes ranging from materials to design and aims to reveal the connections between natural and artificial materials, as well as experiment and modeling. Manuscripts submitted to Materials and Design should contain elements of discovery and surprise, as they often contribute new insights into the architecture and function of matter.