Corrosion is a major problem all over the world. A lot of researches on corrosion are ongoing all over the world and will continue to go on. This paper investigates the effect of corrosion on the tensile properties of AISI 1040 steel in seawater. The samples were austenised at 8300C, 9300C, and 10300C, while some were not. The austenised samples were quenched in water and tempered at 5000C. The samples were further machined into tensile test specimens and then exposed to stagnant aerated seawater. Two samples each from each austenised temperature were tested using a tensile test machine at every 15-days interval, for a duration of 90 days. Some of the fracture surfaces were examined using scanning electron microscope. The results shows a 25% decrease in tensile strength for as received sample, 20.1% decrease for samples austenised at 8300C, 20.9% decrease for samples austenised at 9300C and 22.4% decrease for samples austenised at 10300C at the end of the 90thday.