If you’ve ever wondered what goes into building everything around you, you’ll know that metal is the answer. You might even be able to guess which metal but what about the details of each of these metals? When it comes to the nitty-gritty of these metals and which kind of iron, steel or alloy goes into which product, most of the people are clueless.
While we are well-versed with the role of iron in the industrial sector, what’s often confusing is the different types of iron and iron alloys – cast iron, ductile iron, and wrought iron to begin with. It all begins with a metallurgist listing down his requirements – mostly mechanical, and then an alloy is suggested. Followed by the above comes the choice of finalising a certain type of cast iron in the nearest casting foundry.
‘Cast iron, the term is used for the iron alloys cast in any foundry, and ‘ductile-iron is one such alloy. Let’s find out what types of iron are cast in a foundry?
White Cast Iron: Known for its hardness and abrasion resistance, this alloy cools quicker than other cast irons. It’s often used in bearings and other high-friction applications.
Ductile Cast Iron: An alloy of iron developed in 1948, ductile cast iron is a very important alloy for ferrous foundries. Being much less brittle than other cast irons makes this one of the most preferred alloys in cast iron manufacturing.
Malleable Cast Iron: This alloy is the predecessor of ductile iron, famously used and produced in any cast iron foundry. It is a white cast iron that is heat-treated for a very long period. It is used for small, thin castings under controlled heat conditions as it is a lot less brittle.
Gray Cast Iron: The standard form of “cast iron” is the great cast iron. It has a graphitic microstructure giving it an excellent vibration damping capacity and great machinability. Things that are made from grey cast iron. White and grey cast irons are extremely similar castings. What sets them apart is their colouring, which is only evident when it fractures.
Mechanical Properties Of Cast Iron
Based on the mechanical properties, the applications of each type of iron are decided. Different types of iron are suitable for different applications. Some of the important mechanical properties of cast iron include hardness, ductility, elasticity, malleability, tensile strength, and fatigue strength.
Cast iron is very beneficial for its ability to be moulded into different shapes. The affordable cost can also be added to the list of advantages. To make the cast iron usable in a wide variety of applications, it is often altered by changing the composition depending on the requirements of the casting foundry.
Casting Process Of Cast Iron Foundry
The process of casting is not as simple as it sounds. It includes many steps like making the patterns, melting the metal, pouring the molten metal, cooling it, removing it, cleaning all the parts, and then the final process of examination. The unadulterated cast iron alloy is brought to the cast iron foundry. Silica sand is used for making the moulds because of their capacity to withstand very high heat.
The iron is cast into different patterns in these moulds. Then, it is extracted and sanded to achieve a precise shape. Nowadays, a large number of castings are sent to milling centres for better finishing. A casting foundry may specialise in manufacturing only a special part like an automotive part or produce multiple parts. Some foundries specialise in making parts for the aerospace industries, and others make smaller-scale cast iron pieces.
Govind Steel Company Limited is a 55-year-old company that has continually grown to become one of the largest and leading foundries for Grey Iron Castings and Ductile Iron Castings in India, with an installed capacity of 24, 000 MT. If you have any questions about what we offer for customers or businesses, email us directly at firstname.lastname@example.org or simply visit our website www.govindsteel.com.
On the surface, the process of casting may come off as a simple task. It is just about pouring the liquid metal into a mould and set it. But over the years, the casting process has evolved into various types and intricate processes.
The first process of casting dates back to the 4th century in China. Since then, it has rolled into many innovations and development. In India, casting foundries flourished, providing the best iron products for commercial use.
A casting foundry follows the casting’s essential processes and decides its type based on the requirement and the scale of production. And we will discuss all of it here.
The Iron Casting Process
The iron casting process is carried out in a factory called cast iron foundry. The casting process is carried out in the following steps-
In the cast iron foundry, the primary metal or iron, internal scrap, external scrap, and alloying metal are melted in a furnace. The primary metal or virgin material is the one that is used to form an alloy. The furnace is heated above the melting point of the primary metal.
If the hydrogen concentration is higher in the mixture, it can increase the final product’s porosity. Higher porosity degrades the value of the product. Reducing the amount of hydrogen is called Degassing.
Generally, this is done by passing argon or nitrogen over the melt.
Moulding is usually done with a single-piece pattern or split pattern. The molten metal is poured into the moulds to get the desired shape of the final product. The patterns in the mould are made of wood, plastic, metal, or wax.
The construction of moulds depends on the type of molten metal, type of foundry, the casting size, the required quality of the final product.
4. Pouring And Degating
The molten iron is carefully poured into the mould by automatic machines or giant ladles. Once the metal solidifies, the runners, gates, risers, and heads are removed from the mould using cutting torches, bandsaw, and ceramic cutoff blades. This process is called degating.
The blasting process removes the unwanted debris that is still attached to the solidified material. Usually, this involves propelling tiny grinding balls over the material’s surface to remove unwanted debris like sand.
The tiny grinding balls are made up of glass beads, walnut shells, iron, aluminium oxides, steel, baking powder, etc.
Finally, the material is formed into the perfect dimensions by sanding or machining to even the rough edges. The product is now ready after clearing all the processes in the cast iron foundry.
Casting isn’t just of one type. Other types include sand casting, die casting, low-pressure casting, gravity die casting, centrifugal casting, vacuum die casting, continual casting lost foam casting, etc.
The casting foundry employs the type of casting according to the requirement of the final product. The processing time also varies according to the type of casting used.
We will assist you to know more about the cast iron foundry on http://www.govindsteel.com/.