Cast iron pans are able to withstand the test of time. This is because they have a composition of 2.5-4% carbon, 1-3% silicon and the remaining element is iron. Cast iron is much thicker than carbon steel or stainless steel, but cast iron can retain heat much better than the others.
Carbon is present in the following two forms
Free carbon or graphite
Combined carbon or cementite
The following are the important properties of cast iron that make it a valuable material for engineering purposes.
Low cost.
Good casting characteristics.
High resistance to compression.
Wear resistance.
Excellent machinability.
The compressive strength of cast iron is greater than the tensile strength.
The values of the ultimate resistance of cast iron are indicated below.
Tensile - 100 at 200 N/mm2
Compression - 400 at 100 N/mm2
Cut - 120 N/mm2
Cast iron pans are able to withstand the test of time. This is because they have a composition of 2.5-4% carbon, 1-3% silicon and the remaining element is iron. Cast iron is much thicker than carbon steel or stainless steel, but cast iron can retain heat much better than the others.
Types of cast iron
The following are the types of cast iron used for engineering purposes:
Gray fundition
white casting
cold casting
speckled casting
malleable cast iron
nodular cast iron
alloy cast iron
Properties
These are the properties of cast iron:
Cast iron has good corrosion resistance, so it can be used in water pipes, etc.
It is not attracted to a magnet.
The melting point is about 1250 ºC.
It has a specific weight of 7.5.
Cast iron has a tensile strength of about 150N/mm2 and a compressive strength of about 600N/mm2. Therefore, it is good at compression.
It softens when kept in salt water and shrinks when cooled.
Cast iron may not be useful for forging work due to lack of plasticity.
Advantages of casting
It has good machining and casting properties.
The cast iron has good wear resistance as well as good vibration damping.
It can withstand higher loads and has a good degree of corrosion resistance.
Cast iron has low tensile strength and elongation properties.
It can be given complicated shapes and sizes without the need for expensive machining operations.
Cast iron is available at low cost and has low durability.
Disadvantages of cast iron
Cast iron has low tensile strength.
Castings are section sensitive, due to the slow cooling of thick sections.
The failure of its parts is sudden and total, it does not reflect the elastic limit.
Compared to steel, it has poor machinability
Cast iron has a high fragility.
Cast iron applications
It is used in the manufacture of pipes and to transport suitable fluids.
Cast iron is used to make various machines.
It is used to make automobile parts.
Cast iron is used to build ship anchors.
Cast iron is also used to make kitchen appliances such as pots and pans and utensils.
