Patent ID: 6790254
Filing Date: 2004-09-14
Classification: C21C,C22B,Y02P

Abstract:
A method for producing a metal alloy, wherein a certain desired content of an alloying constituent is fed to said metal alloy in a vessel at overpressure, wherein said alloying constituent is gaseous in its normal state, said method comprising:adding the alloying constituent as a gas and an inert gas to the atmosphere contained in the vessel in such quantities that a particular initial concentration ratio between the gaseous alloying constituent and the inert gas exists in the atmosphere of the vessel; determining changes over time of total gas pressure, changes over times of the concentration of the inert gas and of the gaseous alloying constituent in the atmosphere contained in the vessel, and changes over time of the mean gas temperature of the atmosphere contained in the vessel; determining the mass loss of the inert gas in the atmosphere of the vessel, said mass loss being due to lack of tightness of the vessel, taking into account the total gas pressure, the concentration of the inert gas, the concentration of the gaseous alloying constituent, and the mean gas temperature; determining a theoretical mass loss of the gaseous alloying constituent in the atmosphere from the initial concentration ratio, said theoretical mass loss resulting from the lack of tightness of the vessel; determining the mass fraction of the gaseous alloying constituent transferred into the metal alloy by comparing the theoretical mass loss with the actual mass loss of the gaseous alloying constituent, the actual mass loss of the gaseous alloying constituent being determined from the actual concentration of the gaseous alloying constituent in the vessel; and introducing the gaseous alloying constituent into the atmosphere of the vessel in such quantities and for such a period of time that the metal alloy has a desired content of the gaseous alloying constituent.