When we look at the Fe-C diagram of cast irons, they are shown in the range from 2% to 6.67%. However, since their high carbon content causes brittleness, in practice they are known as a Fe-C-Si alloy containing up to 4.4% carbon and 3.5% silicon.

Although cast irons are brittle and have lower strength properties than steels, they are inexpensive. They are easier to pour. In addition, it is possible to change the properties of any type of cast iron over a wide range with appropriate alloying, good casting control and appropriate heat treatments.


 

What are the uses of cast iron?

• In the automotive industry (crankshafts, differential boxes, steering gearbox, etc.)
• In agricultural machinery (transmission boxes, front wheel forks, etc.)
• In the machinery industry (hydraulic presses, forging press heads and cylinders, gears, axles, machine tools, etc.)
• In the chemical industry (refinery valves, plastic extrusion cylinders, natural gas pipes, etc.)
• In the construction industry (crane parts, concrete mixer parts, etc.)
• In Mining and Metallurgical industry (slag crucibles, molding grades, hot rolling rolls, etc.)
• In the transportation industry (flywheels, marine vehicles, fasteners in trains, train wheels and brake shoes, etc.)

General properties of cast irons

• It has high compressive strength. They show good strength-to-weight ratio.
• It has a lower cost per strength compared to other materials.
• It has a wide range of mechanical/physical properties, for example, strength varies between 10 kg/mm2 and 160 kg/mm2. While the hardness varies between 120-300 Brinell, it is 600 Brinell in special wear-resistant cast irons.
• They show excellent processability at high speeds and production capacities.
• Especially gray cast irons show excellent damping capacity. Their good vibration damping capacity makes them unalterable in engine block production.
• When compared at the same strength levels, they show lower density and higher thermal conductivity than steels.
• It has high resistance to abrasion and corrosion. Chemical analysis can be modified to improve various properties such as corrosion resistance, oxidation resistance, wear, etc.
• The transition from design to final product is rapid. Production steps are quick and easy.
• Since they are close to the eutectic composition, they show good castability properties. They have low melting temperatures. (1150 -1300°C), and it is cheap due to its low melting temperature.
• It has a wide variety to meet engineering and production needs.

Source: https://malzemebilimi.net/dokme-demir-nedir-nerelerde-yılilir-ozelliği-nedir.html