Microstructural Evolution and Mechanical Properties Co relation of  Cold rolled Ferritic Lightweight Steel with Increasing Carbon

Shiv kumar Khaple; V.V. Satya Prasad; B Gopala Krishna; D. V.V. Satyanararana

doi:10.14429/dsj.73.18640

Shiv kumar Khaple DRDO-Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad - 500 058, India https://orcid.org/0000-0002-9439-1801
V.V. Satya Prasad DRDO-Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad - 500 058, India https://orcid.org/0009-0004-2657-8510
B Gopala Krishna DRDO-Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad - 500 058, India https://orcid.org/0009-0007-5120-2250
D. V.V. Satyanararana DRDO-Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad - 500 058, India https://orcid.org/0000-0001-8782-4069

DOI: https://doi.org/10.14429/dsj.73.18640

Keywords: Lightweight steel, Low-density steel, Ferritic steel, Iron aluminium alloys, Thermo Calc, Tensile properties

Abstract

The structure-properties relationship of cold-rolled and annealed Fe-7wt.%Al lightweight steels for varying carbon contents is explored in this work.Unlike Fe-Mn-Al-C based steels, which experienced processing issues, the hot-worked plates of the present steel were successfully cold-rolled to 2mm thick sheets. Various phases present in the steel for different carbon contents as predicted using the ThermoCalc programme are in line with the experimental findings. The basic alloy with 0.01C contains only a ferrite phase, however, the alloys with higher carbon content have a significant quantity of κ-carbide precipitates. The addition of carbon to Fe-7wt.%Al steel has improved its tensile strength significantly (438 to 828MPa). Tensile elongation, on the other hand, has decreased dramatically (26 to 12 percent) with increasing carbon content The reduction in ductility with increasing carbon is mainly ascribed to the increasing κ-carbide precipitates volume fraction with higher hardness, but not due to the environmental embrittlement as observed in case of higher Al containing steels.