DESC:FIELD OF INVENTION

? The present invention relates to increasing efficiency of pure calcium cored wire by delaying its melting
? The cored wire consists of an extruded calcium bar/rod and an intermediate layer between extruded bar and the outer sheath which comprises of a material which will act as an thermal insulator
BACKGROUND INFORMATION

? Steel making is essentially an oxidation process where the impurities of molten metal (pig iron & melted scrap) are preferentially oxidized to join the slag along with fluxes
? The major challenge to steel makers is to reduce oxygen and inclusions, which are formed due to subsequent de-oxidation as they remain intact after casting process & are detrimental to the product quality
? The use of calcium is beneficial but its introduction in liquid steel bath is very difficult due to its low density and high vapour pressure
? The advent of cored wire injection technology and development of calcium bearing material like calcium-silicide, calcium-iron and pure calcium cored wire have enabled steel plant operators to introduce calcium in steel bath
? A cored wire is a continuous steel tube filled with either a calcium bearing material or a ferroalloy material
? Pure calcium cored wire consists of an extruded calcium bar/rod with an outer sheath preferably of steel

OBJECTIVE

? The first object of such cored wire containing insulating material in between extruded Calcium rod and outer steel sheath is to increase the efficiency of cored wire and also delay the melting of cored wire thereby enabling the deeper penetration of the cored wire in the molten metal bath before its own melting and dispersion
? The second object of such cored wire is to increase the recovery of calcium by increasing the depth of immersion as per object 1

SPECIFICATION

? Finish Cored wire outer diameter: 7-18mm,
? purity of calcium: >90%,
? outer steel sheath thickness:0.2-2mm and
? thickness of intermediate insulating material: 0.1-1mm

SUMMARY OF THE INVENTION

? Pure calcium cored wire consists of an extruded calcium bar/rod with an outer sheath preferably of steel
? The injection of this pure calcium cored wire suffers from the drawbacks like low efficiency due to its low melting and boiling temperature and high vapour pressure
? It is well established that efficiency can be increased by delaying the melting and ensuring release of molten calcium near the bottom of ladle
? The main object of the present invention is to delay melting of pure calcium by inserting a layer of insulating material between the outer sheath and the extruded bar thereby increasing the efficiency of cored wire and recovery of calcium in the melt

,CLAIMS:We Claim
1) Cored wire containing material in between extruded calcium rod and outer steel sheath will provide thermal insulation.
2) This thermal insulation will slow down the heating which will result in delay in melting of cored wire.
3) Delay in melting will enable deeper penetration of cored wire in molten metal bath before its own melting and dispersion.
4) This will increase the recovery of calcium by increasing the depth of immersion in molten metal bath.