ABSTRACT 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.
Cite this paper
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.
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