Pig iron is an output obtained as a result of the process of manufacturing iron. Fuel coke with high carbon is utilized in order to heat the iron ore. This results in the production of pig iron which is high in carbon content. The cold pig iron is known as merchant pig iron, which is cast into blocks or ingots. These are then sold to the ferrous as well as steel casting industries in the form of feedstock. There are three types of merchant pig iron, which are as follows:
- Basic pig iron– This is used in electric arc furnace for the purpose of steelmaking.
- Foundry pig iron– This type of pig iron is also known as haematite pig iron and is used in cupola furnaces for grey iron castings.
- High purity pig iron– This is synonymous to nodular pig iron and is used for producing ductile iron castings, which is also known as SG or Spheroidal Graphite. This is used by the manhole covers manufacturers.
Attributes and Application of Foundry Pig Iron for the Grey Iron Casting
This type of pig iron is produced from the specific sources of iron ore. Due to the stable physical as well as chemical analysis it enables the variability of melting and a robust control over the composition of final casting. This eradicates the need for the high-priced casting requirements like heat treatment. This category of pig iron is used in the genres like machine tools, general engineering, and automotive parts manufacturing. Creation of pearlite in the final casting is promoted because of the high iron content on the pig iron.
The application of the foundry pig iron seamlessly promotes the formation of graphite, depletes the primary chill, and enhances machinability. This is highly beneficial for the thin-walled castings. The bulk density of this pig iron is also on the higher side in comparison to the scrap, which needs a lesser space for the storage, and reduced time for charging. In fact, the energy consumption is also reduced remarkably due to higher carbon content. Hence, this type of pig iron is highly beneficial for the manufacturing industries specifically for the casting needs.
Attributes and Application of High Purity Pig Iron for the Ductile Iron Casting
This type of pig iron is also known as HPPI and is characterized by its lower contents of sulfur, phosphorus, and manganese. The presence of the other metal impurities is also negligible that makes the iron highly desirable in various sectors. The application on HPPI can be mainly found in the casting components of the automotive, energy, and engineering industries. There are various advantages associated with HPPI that contributes to the successful ductile iron casting, which are as follows:
- The undesirable elements in the melt are diluted that aids in the depleted cost of scrap.
- The predictable and stable composition of the iron helps achieve better control over the final composition of casting, which leads to an enhanced mechanical output of the casting.
- It demands lower storage space and lesser charge buckets.
- Lower formation of rust leads to the depleted volume of slag.
- Due to the chemical combination of carbon content, the casting is achieved easily with lower consumption of energy.
- The reduced consumption of power and rapid melting leads to the lesser power consumption in the induction furnace.
Hence, the implementation of HPPI in diversified casting needs help reduce the net investment.