Abstract:
Mechanical and corrosion properties of produced grey cast iron using varying weight
percent magnesium in rice husk particulate capsule was investigated. 0.4 and 0.6
wt.% Mg from ferrosilicon magnesium powder incorporated in different rice husk
particulate capsules were used to treat the molten metal in the ladle before pouring
into prepared sand moulds. These were used to produce the cast samples.
Specimens were cut from the cast samples using hacksaw machine for hardness,
tensile and corrosion tests. Optical microscope and scanning electron microscopy
were used to characterize the samples produced. Sample with 0.6 wt.% Mg
incorporated in non-pulverized rice husk particulate capsule had tensile strength of
514.9 MPa compared to other cast samples with tensile strength values of 163 to
415.1 MPa. Hardness and percent elongation values were observed to increase
from 48.5 to 52.5 HRA, and 1.0 to 4.4 % respectively as the weight percent of
magnesium increases. Sample treated with 0.6 wt. % Mg in non-pulverized rice husk
capsule possessed the highest hardness values of 52.5 HRA and 4.4 % for
hardness and percentage elongation respectively. In 3.5 wt. % NaCl solution, it was
observed that the sample treated with 0.6 wt. % Mg had lowest corrosion rate
indicating the cast sample possessed better corrosion resistant in the solution. In
0.3M H2SO4 solution, cast samples using pulverized and rice husk ash capsules
were slightly more susceptible to corrosion in comparison with non-pulverized rice
husk particulate capsule treated with 0.6 wt. % magnesium.
