The main differences between cast iron and gray cast iron are their chemical composition, microstructure, mechanical properties and application areas.
Chemical composition and microstructure
Gray cast iron: Carbon mainly exists in the form of free graphite, and the silicon content is relatively high (1.8%-2.4%), which helps to promote the graphitization process and improve the machinability and wear resistance of the material.
Cast iron: Usually refers to an iron-carbon alloy with a carbon content greater than 2.1%, including various types, such as white cast iron and ductile cast iron. All carbon in white cast iron exists in the form of cementite, while ductile cast iron is spheroidized and the graphite is spherical.
Mechanical properties
Gray cast iron: It has certain strength, plasticity and toughness, but relatively low. Its tensile strength is ≥225 MPa, and its compressive strength can reach 3-4 times the tensile strength (about 675-900 MPa), which is suitable for pressure-resistant scenarios.
Cast iron: The mechanical properties of different types of cast iron vary greatly. For example, white cast iron has high hardness but poor toughness, is brittle, and cannot withstand cold and hot working. Ductile cast iron has high strength and good toughness, and is suitable for applications that require high strength and good toughness.
Application areas
Gray cast iron: widely used in the manufacture of various complex castings, such as parts in machine tools, automobiles, ships and other industries, and also used to manufacture parts that withstand pressure or vibration, such as papermaking dryers, pump bodies and more.
Cast iron: includes many types and has a wide range of applications. For example, white cast iron is mainly used to manufacture parts that require high hardness and wear resistance, such as plows and grinding discs. Ductile cast iron is used to manufacture internal combustion engines, automotive parts and agricultural machinery and more, because of its high strength and good toughness.
Generally speaking, foundries will have complete casting suggestions and give the right metal material casting options according to customer needs. For example, Mulan Metal. If you need large-scale casting services, you can choose Mulan Metal, which has 12 years of OEM casting experience and customers in more than 30 countries. Complete certificates can meet the needs of customers in different countries.
Here is our OEM cast iron parts Display：
