Microstructural Evolution and Deformation Behavior of Cold-Rolled Fe-Mn-Al-C Low-Density Steel

Abstract:

Low-density medium-manganese steels offer a vast development prospect for industrial application due to their outstanding combination of mechanical properties and density reduction. The microstructural evolution following tensile deformation of cold-rolled and annealed Fe-10Mn-10Al-0.7C steels was investigated by means of SEM and TEM microstructure analysis and XRD measurements. Annealing in the range of 700-1100 °C led to an austenite-ferrite dual-phase microstructure that was characterized by tensile strength of 700-1100 MPa and elongation of 6-34%. κ-carbides were observed in steels annealed at relatively low temperatures (700-850 °C). The steel exhibited the optimum combination of tensile strength of 930 MPa and elongation of 34% after annealing at 900 °C for 0.5 h. The stacking fault energy was estimated to be 69mJ/m2 considering the difference between average constituent and practical constituent of austenite caused by the high ferrite fraction. The deformed microstructures of the austenite exhibited the typical planer glide characteristics in sequence of dislocation array, Taylor lattice, Taylor lattice domain and microband. And the wavy glide occurs in ferrite was manifested by tangled dislocation and dislocation cells.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 323-328
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.323
• Online since: December 2018
• Authors: Nai Peng Zhou, Ren Bo Song*, Xuan Li, Wen Jie Niu
• Keywords: Low-Density Steel, Planer Glide, Stacking Fault Energy, Tensile Deformation, Wavy Glide

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