Method to obtain a manganese steel alloy of the Hadfield type containing a percentage weight between 10% and 20% of manganese, comprising: a first step wherein a quantity of manganese steel scrap or carbon steel scrap is melted in order to define a metal bath, a second step wherein, in order to deoxidize said metal bath, a determinate percentage weight of aluminum is added during tapping into a ladle, a third step wherein said metal bath is cast at a casting temperature from 1410° C to 1450° C, wherein, between said second step and said third step a fourth step is also provided during tapping into the ladle wherein a determinate percentage weight of nitrogen is added to said metal bath, characterized in that between said second step and said third step, in addition to said fourth step, a fifth step is provided when tapping is completed wherein a percentage weight of titanium is added to said metal bath in the ladle, comprised between 0.3% and 5% and once the titanium has been introduced into the metal bath, an injection of argon gas is performed, wherein casting of the liquid metal bath obtained in the fifth step occurs after an injection of argon gas is performed in the liquid metal bath under the slag, wherein said determinate percentage weight of aluminum is between 0.005% and 0.035%, wherein said determinate percentage weight of nitrogen is between 0.0001% and 0,10%, wherein between said first step and said second step a sixth step is also provided wherein a determinate percentage weight of manganese between 0% and 20% in weight and a percentage of chromium between 0.001% and 10% in weight are added to said metal bath and wherein between said first step and said sixth step one or more chemical analyses are carried out in order to verify the chemical composition of said liquid bath at the end of said first step to determine said determinate percentage weight (P4, P5) of said iron alloy to be added in said sixth step. a first step wherein a quantity of manganese steel scrap or carbon steel scrap is melted in order to define a metal bath, a second step wherein, in order to deoxidize said metal bath, a determinate percentage weight of aluminum is added during tapping into a ladle, a third step wherein said metal bath is cast at a casting temperature from 1410° C to 1450° C, wherein, between said second step and said third step a fourth step is also provided during tapping into the ladle wherein a determinate percentage weight of nitrogen is added to said metal bath, characterized in that between said second step and said third step, in addition to said fourth step, a fifth step is provided when tapping is completed wherein a percentage weight of titanium is added to said metal bath in the ladle, comprised between 0.3% and 5% and once the titanium has been introduced into the metal bath, an injection of argon gas is performed, wherein casting of the liquid metal bath obtained in the fifth step occurs after an injection of argon gas is performed in the liquid metal bath under the slag, wherein said determinate percentage weight of aluminum is between 0.005% and 0.035%, wherein said determinate percentage weight of nitrogen is between 0.0001% and 0,10%, wherein between said first step and said second step a sixth step is also provided wherein a determinate percentage weight of manganese between 0% and 20% in weight and a percentage of chromium between 0.001% and 10% in weight are added to said metal bath and wherein between said first step and said sixth step one or more chemical analyses are carried out in order to verify the chemical composition of said liquid bath at the end of said first step to determine said determinate percentage weight (P4, P5) of said iron alloy to be added in said sixth step.