Structural Evolution and Properties of Hot Rolled Steel Alloys

Emmanuel Isaac Akpan, Idoko Andrew Haruna

Department of Materials and Production EngineeringAmbrose Alli University, Ekpoma, Edo State, Nigeria.

DOI: 10.4236/jmmce.2012.114029                

Abstract

Microstructural evolution during hot rolling of mild steel (0.3%C) has been considered to determine its relationship with the mechanical properties. Strain, strain rate, temperature and Zener Hollomon parameter were considered as structural parameters. Deformation parameters were collected industrially and the Zener Hollomon parameter calculated from the formula;Z=e exp(Q/RT). Microstructural features considered were grain size, inclusions, distribution of phases and banding. The grain size was calculated using the ASTM grain size number and the fraction distribution of phases was determined using a 10×10 grid counting. Mechanical properties considered were ductility, tensile strength, hardness and yield strength determined by laboratory experiments. Grain size was found to be inversely related to the Zener Hollomon parameter. Strength (Tensile, Yield and Fracture) were found to be inversely related to grain size but directly related to fraction distribution of phases. Banded structure and inclusions were found to be detrimental to strength and ductility.

Keywords

Recrystallization, Microstructure, Zener Hollomon Parameter, Deformation, Rolling, mild steel

Conflicts of Interest

The authors declare no conflicts of interest.

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