Author(s)

S. B. Hassan, J.B. Agboola, V.S. Aigbodion, E.J. Williams

Department of Mechanical Engineering, Federal University of Technology, Minna, Nigeria..
Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Samaru,Zaria, Nigeria..

The hardening characteristics of medium carbon steel and ductile cast iron using neem oil as quenching medium has been investigated. The samples were quenched to room temperature in Neem oil. To compare the effectiveness of the neem oil samples were also quenched in water and SAE engine oil the commercial quenchants. The microstructures and mechanical properties of the quenched samples were used to determine the quench severity of the neem oil. The result shows that hardness value of the medium carbon steel increased from 18.30HVN in the as-cast condition to 21.60, 20.30and 20.70HVN while that of ductile cast iron samples increased from 18.90HVN in the as-cast condition to 22.65, 20.30 and 21.30HVN for water, neem oil and SAE40 engine oil respectively. The as-received steel sample gave the highest impact strength value and water quenched sample gave the least impact strength. The impact strength of the medium carbon steel samples is 50.84, 41.35, 30.50 and 45.15 Joule and that of ductile iron is 2.71, 1.02, 0.68 and 1.70 Joule for as-cast condition, neem oil, water and SAE 40 engine oil quenched respectively. The microstructure of the samples quenched in the Neem oil revealed the formation of martensite. Hence, neem oil can be used where cooling severity less than that of water but greater than SAE 40 engine oil is required for hardening of plain carbon steels and ductile cast iron.

Hardening characteristics, Ductile Cast iron, Medium Carbon Steel, Neem oil andQuenchant.

S. Hassan, J. Agboola, V. Aigbodion and E. Williams, "Hardening Characteristics of Plain Carbon Steel and Ductile Cast Iron Using Neem Oil as Quenchant," Journal of Minerals and Materials Characterization and Engineering, Vol. 10 No. 2, 2011, pp. 161-172. doi: 10.4236/jmmce.2011.102011.