The Jominy end-quench test which follows ASTM: A-255, is used to measure the hardenability of steels. It consists on heating of a standardized cylindrical specimen of material in test (25.4 mm diameter and 100.0 mm in length) until the austenitizing temperature, and then cooling it at one end through of water in order to induce the formation of the martensitic structure. After that, the hardness is measured along the specimen at intervals of
1.59 mm between each measure. Obviously, the first measure pre- sents high values of hardness due to the formation of martensite by high cooling water. Consequently, the hardness decreases in more distant positions of the cooled surface, because in these points, the cooling rates are lower resulting in the formation of phases such as ferrite, pearlite and bainite.