How is grey cast iron manufactured?
A high cooling rate and a low carbon equivalent favours the formation of white cast iron whereas a low cooling rate or a high carbon equivalent promotes grey cast iron. During solidification, the major proportion of the carbon precipitates in the form of graphite or cementite.
Can grey cast iron be machined?
The machinability of gray cast iron is generally quite good because of the presence of near continuous graphite flakes in the microstruc- ture. The flakes’ presence promote chip formation,1 as well as lubrication during the machining operation.
How do you cast a grey iron?
To make castings, molten grey iron is poured into the mold, taking its shape. To create a mold using the skin-dried molding method, also known as air-dried molding, operators mix water, sand, a binder like clay and bonding additives and then dry it with a torch or heating lamp.
What is the composition of grey cast iron?
Grey Cast Iron (Gray iron) is so called because of the colour of the fracture face. It contains 1.5-4.3% carbon and 0.3-5% silicon plus manganese, sulphur and phosphorus. It is brittle with low tensile strength, but is easy to cast.
How is cast iron made?
It is made by reducing iron ore in a blast furnace. The liquid iron is cast, or poured and hardened, into crude ingots called pigs, and the pigs are subsequently remelted along with scrap and alloying elements in cupola furnaces and recast into molds for producing a variety of products.
Is cast iron easy to machine?
Cast iron is typically much easier to machine than steel. The graphite structure in cast iron breaks away more easily, and in a more uniform manner. Harder irons, such as white iron, are much more difficult to machine due to their brittleness.
Why is grey cast iron highly machinable?
The graphite in gray cast iron has a flake-like structure which is largely responsible for the high machinability of this metal. The flake-like graphite structure gives rise to discontinuities in the metal matrix and subsequent reduced cutting forces.
How many flakes are in grey cast iron?
Gray iron is so named because its fracture has a gray appearance. It contains carbon in the form of flake graphite in a matrix that consists of ferrite, pearlite, or a mixture of the two.
How is cast iron manufactured?
Is grey cast iron magnetic?
The magnetic properties of gray cast iron vary widely, from low permeability and high coercive force to high permeability and low coercive force. These changes mainly depend on the mictrostructure of gray cast iron.
What is iron manufacturing?
Manufacture of iron. Iron is produced by reduction of iron ore, which is often a mixture of oxides, using carbon, carbon monoxide, and hydrogen. While the blast furnace is the dominant reduction process other technologies are emerging which operate on a smaller scale.
Where is cast iron manufactured?
Most cast iron sold by Lodge is produced in its foundry in South Pittsburg, Tennessee, which has been in operation since the company was founded.
What type of welding rod is used for cast iron?
Ferro-Nickel
There are two common types of Cast iron Welding Rod, Ferro-Nickel and Pure Nickel. Ferro-Nickel are typically 53% Steel and 47% Nickel. Ferro-Nickel Rods are cheaper than pure Nickel and are ideal for welding Cast Iron to Steel.