Method for determination and control of the amounts of nitrogen dissolved in metallic liquid phases and device for its realization
AssigneeCentro Sviluppo Materiali S.p.A.
InventorsCarlo Borgianni, Antonello Di Donato, Maria Ilaria Pistelli
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Abstract
The present invention refers to a method for determination and control of the amount of nitrogen dissolved in metallic liquid phases and to a device permitting, when placed in the steel producing plant and for instance in the tundish or in the continuous casting mold, the determination of nitrogen content directly from the liquid phase. Such a device can point out possible nitrogen pick-up in real-time, thus permitting to immediately intervene.
Claims15
Method of measuring and controlling the nitrogen content in a liquid metal bath, in which an inert carrier gas is bubbled through said liquid metal bath to promote a nitrogen transfer from said bath to said carrier gas, thus forming a first gaseous mixture comprising said carrier gas and nitrogen, said mixture being collected and withdrawn from said metal bath, characterized in that (i) a known quantity of oxygen is added with a known flow rate to said first gaseous mixture to form a second gaseous mixture comprising carrier gas, nitrogen and oxygen;
- (ii) the nitrogen contained in said second gaseous mixture is oxidized to nitrogen oxides, comprising NO2;
- (iii) the NO2 amount thus formed is measured and correlated to the nitrogen content in said liquid metal bath;
- (iv) the thus obtained NO2 amount and correlated nitrogen content in said liquid metal bath are then loaded in a computer which compares them with a desired nitrogen content in the metal bath, and displays necessary measures to bring the measured nitrogen content in said metal bath to the said desired nitrogen content.
Dependencies are inferred from the claim text.