DESC:Field of Invention:
This invention relates to CaSi cored wire with increased Calcium (Ca) content and reduced Si content compared to conventional CaSi cored wire to suit the requirement of a particular batch of some steel grades having Si restriction
The said Cored Wire consists of a powder, the main constituents of which being Si and Ca and one or more steel strips for encasing the filler material

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
? CaSi powder is generally a eutectic compound in which CaSi is a pre-fused mixture in which Calcium (Ca) is around 30% and Silicon (Si) is around 65% (conventional CaSi).
? Due to dynamic situations prevailing in steel making shops, in some of the liquid steel batches the Si content becomes so high that the amount of CaSi wire to be injected for achieving Ca requirement becomes limited.
? In such cases it becomes imperative that the reduced amount of CaSi is used and the balance Ca requirement is made up with some other type of Ca addition like pure Ca wire or Calcium iron (CaFe) wire
? The steel plant operators need an easier solution in such situations
? In search of such easier solution the current study of developing a special CaSi cored wire had become necessary

Objective:
? The first object of this invention is to provide operational flexibility and sustainable solution of steel making units
? The second object is thus to provide breakthrough solution in industry to reduce their total cost by enabling them to eliminate any additional requirement of other type of Ca wire
? The third object is to increase the efficiency of Ca addition in the form of CaSi wire to make it more sustainable as per first object; the efficiency of CaSi wire is always better than other type of Ca wires
? The fourth object of such innovative cored wire containing CaSi with higher Ca content as filler material is to make a standard product for liquid steel batches which has limitation of conventional CaSi addition
? The fifth object is to eliminate necessity to use second type of Ca wire in such batches of steel

Specification:

? CaSi Cored Wire Specification: Ca: 28-80%, Si: 20-65%
? Pure Calcium: >90% Purity
Summary of the invention:
? Cored wire consists of a powder, the main constituents of which being Si and Ca
? The uniqueness of such powder is that the Ca content is more than the conventional CaSi powder
? The filler material is covered with one or more steel strips
? To increase the efficiency of Ca and minimize the effect of Si in Si restricted batch of steel this new product simplifies the operation by eliminating the need of an additional cored wire for achieving Ca requirement
? This product will reduce the cost and inventory at customer end

,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 a cored wire consisting of a powder with the main constituents as CaSi and pure calcium
3. The process as claimed in claim 2, wherein a cored wire consisting of a CaSi powder with increased Ca content and reduced Si content compared to conventional CaSi cored wire
4. The process as claimed in claim 2, wherein a cored wire consisting of CaSi with Ca% in between 28-80% and Si% in between 20-65%
5. The process as claimed in claim 2, wherein the said cored wire consists of one or more steel strips (Reference Patent Application No 201931045265)
6. The process as claimed in claim 2, wherein the said cored wire will suit the requirement of a particular batch of steel grades having Si restriction
7. The process as claimed in claim 2, wherein the said cored wire reduces the inventory cost by enabling steel plants to eliminate any additional requirement of other type of Ca wire
8. The process as claimed in claim 4, wherein the said cored increases the efficiency of CaSi cored wire
9. The process as claimed in claim 7 and claim 8, wherein due to reduction of cost and improvement in efficiency of CaSi cored wire at customer end will minimize carbon emission and contribute towards our efforts in achieving sustainability goals.