FUW TRENDS IN SCIENCE & TECHNOLOGY JOURNAL
(A Peer Review Journal)
e–ISSN: 2408–5162; p–ISSN: 2048–5170
keywords: Independent variables, mechanical properties, microstructures, rolled steel
Mechanical properties of carbon steel are controlled by the ferrite and pearlite fractions, carbon content, grain sizes and strength of both phases. The carbon content affects the pearlite hardness and the hardenability. This work is aimed at studying the effect of chemical composition of ten (10) alloying elements and four (4) sectional sizes (12 – 25 mm diameter) as independent factors on the microstructure and mechanical properties of rolled carbon steels produced from the inland rolling mills. Micro-structural characterization, impact strength and tensile test were made for each section size. The analyses were based on the experimental data from which theEngineers obtain their design data and provide acheck on the standard of raw materials and heat treatment methods being used. It was observed from the studies that the volume of pearlite formed was more in 25mm diameter rods and decreases with reduction in sizes across 20, 16 and 12 mm as a result of the kinetic of cooling. This accounted for the increase in the impact strength from 32J for 25 mm to 100J for 12 mm rods as the sectional size led to lower kinetic of cooling that favoured the proportion of pearlite phase which raises the impact transition temperature and hence, have adverse effect on toughness and ductility. However, the carbon and manganese have pronounced effect in enhancing the tensile strength of 25 mm rods which was 772.72 Nmm-2. But the 12 mm rods seem to have double advantage of both the composition and section sizes which enhanced its strength to 673.16 Nmm-2.
Adnan C., Akin D., Osman S. and Nazim U. (2010). Effect of Carbon Content on the Mechanical Properties of Medium Carbon Steels. Verlag der Zeitschrift f¨ur Naturforschung, T¨ubingen• http://znaturforsch.com. 0932–0784 / 10 / 0500–0468 $ 06.00 Pp 468-472. ASTM E23. 2008, Standard Test Method for Izod Bar Impact Testing of Metallic Materials, American Society of Testing and Materials. ASTM E8. 2008, Standard Test Method for Tension Testing of Metallic Materials, American Society of Testing and Materials. Balogun SA, Lawal GI, Sekunowo OI &Adeosun SO 2011. Influence of finishing temperature on the mechanical properties of conventional hot rolled steel bar. J. Engr. & Techn. Res., 3(11): 307-313. Christensen RM 2008. Observations on the Definition of Yield Stress.Acta Mech., 196: 239-244. Christensen RM 2011. Defining Yield Stress and Failure Stress (Strength), Failure criterial.com. Cottrell AH 1981. The Mechanical Properties of Matter. Krieger, Malabar, FL. Fadare DA, Fadara TG & Akanbi OY 2011. Effect of Heat Treatment on Mechanical Properties and Microstructure of NST 37-2 Steel. Journal of Minerals & Materials Characterization & Engineering, Vol. 10, No.3, Pp.299-308. jmmce.org Metals Handbook Desk Edition, Second Edition 1998. ASM International, pp. 153-173. www.asminternational.org. Davis, J. R. Editor. Hull D&Bacon DJ 2001. Introduction to Dislocations. Butterworth Heinmann, Oxford. Jenan MN2014. The Effect of cooling rate on mechanical properties of carbon steel (ST 35). Diyala J. Engr. Sci.,7(1): 109-118. ISSN 1999-8716. Khanna OP 2009. Materials Science and Metallurgy. Dhanpat Rail Publication Limited, New Delhi,pp. 17-12. Krzysztof Muszka, Kanusz Majta and Lukasz Bienias (2006). Effect of Grain Refinement on Mechanical Properties of Microalloyed Steels. Metallurgy and Foundry Engineering, Vol 32, No 2 Valeria L de la Concepcióna, Hernán N, Lorussoa B, Hernán G & Svobodab C 2015. Effect of carbon content on microstructure and mechanical properties of dual phase steels. International Congress of Science and Technology of Metallurgy and Materials, SAM-CONAMET 2013. Procedia Materials Science 8 (2015) 1047 – 1056. Available online at www.sciencedirect.com
