Schematic illustration and dimensions of the Jominy test considered in the present
work are shown in Figure 1. A steel cylinder (diameter: 25 mm; length: 100 mm) is
heated within the austenitic domain during a preset time and quenched from its lower
end with a controlled and standardized jet of water. The temperature of the water must
be between 15 and 25 °C. The cooling rate along the Jominy test specimen varies from
about 225 °C/s to 2 °C/s, depending on the distance from the quenched end. After
cooling the Jominy bar is polished parallel to the cylinder axis on both sides. The sur-
face is ground back to remove any effects of decarburisation and the hardness profile
is measured along this grounded surface at intervals from the quenched end. Thus,
hardness measurements are carried out along the cylinder axis as a function of the
distance from the quenched extremity.