The main difference between iron and cast iron is that the iron is pure but the cast iron has the carbon content between 2% and 4%. Therefore, cast iron has relatively low melting point compared to that of the pure iron.
Furthermore, cast iron has lower tensile strength, higher ductility and malleability compared to that of the pure iron.
Let us discuss some more differences between iron and cast iron in terms of their properties, uses, etc.
1. What is Iron?
Iron is a metal that occurs naturally in the earth’s crust. It is one of the most abundant elements. Iron is a soft, ductile and ferromagnetic metal with the chemical symbol Fe. It is the second most abundant metal on the earth crust after aluminum.
Iron can be refined to produce steel, which is stronger than iron. Steel is obtained by removing carbon and other impurities from iron through a process called smelting. Iron has many industrial uses such as building construction, automobiles, and shipbuilding.
The pure form of iron is a silver-colored, tough metal that can be magnetized. Iron is an element which can be alloyed with other elements and metals to form a wide variety of steels.
The most common element used as an alloying agent with iron is carbon. The addition of carbon improves the hardness and strength of the resulting steel alloy.
2. What is Cast Iron?
Cast iron is an alloy of iron, carbon and silicon. The carbon content in cast iron ranges from 2-4%. Cast iron has a good fluidity and thus it can be easily molded into different shapes and sizes.
It is also easy to cast since it melts at a lower temperature than steel or wrought iron. Therefore, large structures can be easily formed using this material. It is also non-corrosive and highly resistant to wear and tear when compared to other materials such as aluminium or brass
Cast iron is a ferrous alloy that is made by re-melting pig iron in a capola furnace until it liquefies. The molten iron is poured into molds or casts to produce casting iron products of the required dimensions.
Cast iron has been used for centuries for many different purposes. For example, it was used during the Middle Ages to create cannons.
It was not until the 19th century that cast iron was used to create stoves and other household items.
3. Properties of Iron vs Cast Iron
• Cast iron has more carbon content than wrought iron (2-4% carbon). Wrought iron has less than 0.25% carbon content
• Wrought irons are made by heating an ingot till white hot state and then hammering it into desired shapes whereas cast irons are made by casting the molten metal into desired shapes
• Iron is an element and a metal. It is found in nature as an ore, and the estimate of its abundance in the earth’s crust is approximately 5%. Iron is used for many purposes such as in buildings, bridges, cars, airplanes and household items. Steel is an alloy of iron with carbon (about 0.1%-1%, depending on type) as the main alloying element.
• Cast iron contains 2-4% carbon and 1-3% silicon; it is brittle, strong in compression and has excellent casting qualities. Cast iron can be cast into intricate shapes because of its good fluidity and because it shrinks very little during solidification.
4. Uses of Iron and Cast Iron
• Iron is a common metal known for its strength and durability. You can find it in many everyday items, from pots and pans to railings and ladders.
In addition to its uses in cooking and construction, iron is used extensively in industry.
It’s used as a catalyst in chemical reactions, as a sheeting material for radiation shielding, and in the manufacture of some types of paints and rubber products.
• Iron compounds are used to purify water and to make dyes, pigments, wood preservatives, insecticides, mordants (substances that help dye fix to fabric) and other products.
• Cast iron is an alloy made by combining iron with carbon. The term “cast” refers to the process by which molten iron is poured into molds to produce parts or finished products.
•Cast iron has been used in bridges, building facades, ornamental street lamps and fences, stove grates, radiators and many other applications. Because it’s not as ductile as steel, cast iron may be the preferred material when compressive strength is the quality most needed in a project.
• Iron is a highly useful metal that finds its applications in various fields and hence it is a very important component of our mechanical industry. The most common uses of iron are discussed below:
Pipes: Iron pipes are used to transport water, steam and other fluids. They can be galvanized with zinc to increase the resistance to corrosion.
Structural work: Iron is extensively used as a construction material for making gates, grills, railings etc.
Kitchen utensils: Cast iron pans and pots have excellent heat retention property, which makes them ideal for cooking purposes. They are also cheap and easy to maintain. However cast iron is sensitive to acidic foods and may react with them leading to rusting. Cast iron pots and pans can be restored by re-seasoning them with oil or fat before each use.
5. Key Differences Between Iron and Cast Iron
Cast iron and wrought iron are both strong, durable materials that can be used for the same basic applications. They are frequently used in vases, sculptures, furniture, and architectural decorations due to their moldability by casting or beaten, respectively.
• Iron is a metal with atoms arranged in a crystal structure called body centered cubic (BCC), where adjacent atoms share electrons and form a close-packed structure.
• Cast iron has the same crystal structure as iron, but it also contains carbon and silicon.
Iron is an element, while cast iron is an alloy. Iron is hard and brittle unless heat treated, whereas cast iron is less brittle.
Cast iron typically contains 2–4% carbon, whereas iron typically contains 0.005–0.008% carbon.