DESC:Field of Invention:
This invention relates to application of mild steel (MS) strip for manufacturing of cored wire using either single strip or multiple strip (Refer Patent application no. 201931045265, dt.07/11/2019, 201931046105, dt.13/11/2019 and 201931047516 dt.21/11/2019. This invention also relates to usage of MS alone or in combination with other low carbon steel grades like deep drawing grade (DD) and extra deep drawing grade (EDD) for manufacturing of cored wire.
The cored wire consists of filler material encased in a tube made up of single steel strip or multiple steel strips

Background Information:
? Steel making is essentially an oxidation process where the impurities of molten metal 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, pure calcium cored wire etc. have enabled steel plant operators to introduce calcium efficiently in steel bath
? A cored wire is a continuous steel tube filled with either a calcium bearing material or a ferroalloy material
? The steel tube is usually made of a single strip with DD/EDD grade of steel
? Conventionally DD/ EDD grade steel strip is used for its high ductility/formability
? Patented (Refer Patent application no. Kolkata/ 201931045265, dt.07/11/2019, Kolkata/201931046105, dt.13/11/2019 and Kolkata/ 201931047516 dt.21/11/2019) studies have enabled use of multiple steel strip of same thickness, same width or of different thickness or different width

Objective:
? The first object is to reduce carbon emission by reducing of consumption of higher-grade steel in cored wire.
? The second object of such cored wire containing MS strip alone or along with DD/EDD is to reduce the total cost of cored wire
? The third object is to provide strength to the cored wire thereby enabling the deeper penetration of the cored wire in the molten metal bath before its own melting and dispersion.
? The fourth object is to maintain the strength during manufacturing of cored wire even though there is a reduction in thickness when using multiple strip
? The fifth object is to maintain the strength during feeding operation even though there is a reduction in thickness when using multiple strip
Specification:

? Finished Cored wire diameter: 4-18mm,
? Grade of steel: Mild steel (carbon content more than 0.03%), DD/EDD
Summary of the invention:
? Based on patented (Refer Patent application no. Kolkata/ 201931045265, dt.07/11/2019, Kolkata/201931046105, dt.13/11/2019 and Kolkata/ 201931047516 dt.21/11/2019) studies which enabled use of multiple steel strips of same thickness, same width or of different thickness, different width, the current study has been taken up to use MS grade for manufacturing cored wire
? Substantial reduction in thickness of the strip has enabled use of MS without compromising formability significantly
? MS will also give substantial strength during forming and application of cored wire even though there is a reduction of thickness
? MS grade steel strip increases the strength of cored wire which enables deeper penetration in the melt
? This invention enables usage of cheaper substitute of DD/EDD grade steel, either fully or partly, without compromising or the efficiency

,CLAIMS:1. A cored wire injection process for introducing fluxes and alloying additives in liquid steel bath after adjusting bath temperature and the chemistry of liquid steel in a secondary treatment unit according to requirements: characterized in that said additives are released close to the bottom of the ladle by injecting at a predetermined speed a prefabricated cored wire of appropriate dimensions, depending on the grade of liquid steel, treatment temperature and ladle size / liquid column height
2. The process as claimed in claim 1, wherein Mild Steel strip alone is used for manufacturing cored wire
3. The process as claimed in claim 2, wherein usage of Mild Steel strip reduces the overall cost of cored wire
4. The process as claimed in claim 2, wherein a cored wire containing Mild Steel strip should have carbon content more than 0.03%
5. The process as claimed in claim 2, wherein a cored wire containing Mild Steel strip should give substantial strength during manufacturing even though there is a reduction in thickness when using multiple strip or even single strip
6. The process as claimed in claim 2, wherein a cored wire containing Mild Steel strip increases the strength thereby enabling the deeper penetration of the cored wire in the molten metal bath before its own melting and dispersion
7. The process as claimed in claim 2, wherein a cored wire containing Mild Steel strip improves the recovery in high carbon grade