POTENTIAL OF CANE MOLASSES AS QUENCHING MEDIUM FOR (0.61%C) HIGH CARBON STEEL
POTENTIAL OF CANE MOLASSES AS QUENCHING MEDIUM FOR (0.61%C) HIGH CARBON STEEL
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Date
2015-10
Authors
MAMUDA, RAYYAN DODO
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Abstract
The effect of cane molasses as quenching medium for high carbon steel was investigated.
Samples of high carbon steel were spheroidized annealed and then machined prior to the
hardening process. Molasses of eleven different viscosities were prepared by adding varying
amounts of water; such that the ratios of molasses to water were 1:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1,
5:1, 5.5:1, 6:1, 6.5:1 and 1:0. The samples were normalized and then austenitised at 800oC. They
were then soaked for 40 minutes and then quenched in water, engine oil, raw molasses and
molasses solutions (in the ratio mentioned above). Half of quenched samples (ninety one) were
further tempered at 350oC, held for 40 minutes and then air-cooled. Cooling curves of all the
quenching media used were developed. Specific heat capacities of the various media used were
determined. Mechanical properties (tensile strength, percent elongation, hardness and impact
energy) of the test samples were evaluated. The test results obtained showed that for the
quenched specimens, the highest value of tensile strength (1360 N/mm2) and hardness (679
HVN) was obtained in 1:1 molasses to water solution. Minimum impact strength was also
obtained from sample quenched in 1:1 molasses to water solution. Microstructures of the various
samples were analyzed using optical microscopy (OM) and scanning electron microscopy
(SEM). In all the tests samples martensite structure was observed. Quench cracks were observed
in specimen quenched in water and 1:1 molasses to water solution. It was also observed that
molasses solutions with mixture ratio 1:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, and 5:1 had quenching
severity higher than that of engine oil but lower than that of water while molasses solution
(5.5:1) gives cooling rate close to that of engine oil. The research showed that molasses solution
with mixture ratio 3:1 gave good combination of mechanical properties (4.2% percent
elongation, 905N/mm2 tensile strength, 602HVN hardness and 158KJ/mm2 impact strength); and
is hereby recommended to be used as quenching medium for high carbon steels
Description
IN PARTIAL FULFILMENT OF THE REQUIREMENTS
FOR THE AWARD OF A MASTER DEGREE IN METALLURGICAL AND
MATERIALS ENGINEERING.
DEPARTMENT OF METALLURGICAL AND MATERIALS ENGINEERING
FACULTY OF ENGINEERING
AHMADU BELLO UNIVERSITY ZARIA,
NIGERIA
Keywords
POTENTIAL,, CANE MOLASSES,, QUENCHING MEDIUM,, (0.61%C) HIGH CARBON STEEL,