Effect of Austenising Temperature on the Tensile Property of AISI 1040 Steel

Abstract

Every day, a lot of engineering materials experience failure as a result
of stress. This has resulted in loss of life and property. This paper
investigates the effect of varying austenising temperature on the tensile
properties, microstructures and fractography of 0.4%C steel and how it
affects the strength of steel. The samples were austenised at 8300C,
9300C, and 10300C respectively while some were not austenised. The
austenised samples were quenched in water and tempered at 5000C.
The samples were further machined into tensile test specimen and tested
using the tensile test machine. Some of the fracture surfaces were
examined using scanning electron microscope. The results showed a
47.6% increase of tensile strength at 10300C from the as received
sample and a subsequent 36.7% decrease in the percentage
enlongation. For the austenised samples, the result showed a 3.6%
increase of tensile strength at 10300C from the sample austenised at
8300C and a subsequent 21.9% decrease in percentage enlongation,
while there was a 2.5% increase of tensile strength at 10300C from the
sample austenized at 9300C and a subsequent 16.2% decrease in
percentage enlongation. This agrees with the fracture surfaces that
likely show a gradual decrease in ductility as seen from the reduced
dimples and tear rigdes in the fracture surfaces, as the austenising
temperature increases.