Definition：
Carbon steel: mainly refers to the mechanical properties depends on the carbon content of the steel, generally does not add a large number of steel alloy elements, sometimes known as ordinary carbon steel or carbon steel. Carbon steel is also called carbon steel, and its carbon content is less than 2% WC carbon alloy. Carbon steel contains a small amount of silicon, manganese, sulfur, and phosphorus, which can be divided into carbon steel based on the use of carbon steel, carbon tool steel and easy cutting structural steel three carbon structural steel divided into structural steel and can be divided into low carbon steel (WC < 0.25%), medium carbon steel (WC 0.25%- 0.6%) and high carbon steel (WC> 0.6%). According to the content of phosphorus and sulfur, carbon steel can be divided into ordinary carbon steel (high phosphorus and sulfur content), high quality carbon steel (phosphorus and sulfur content is lower) high quality steel (phosphorus content, sulfur content is lower) carbon steel with higher carbon content, the higher the hardness, the higher the strength, but the lower the plasticity.
Alloy steel: Based on carbon steel, intentionally adding one or more alloying elements to improve the applicability and technological properties of iron-based alloys, called alloy steels. Alloy steel is a steel containing silicon and manganese as an alloy element or deoxidizing element. Other alloy elements such as chromium, nickel, molybdenum, vanadium, titanium, copper, tungsten, aluminum, cobalt, niobium, zirconium, and other elements have some nonmetallic elements (such as boron, nitrogen, etc.). According to the content of alloying elements in steel, it can be divided into low alloy steel, medium alloy and high alloy steel.
Chemical composition difference
(1) carbon steel: a. Low carbon steel (C less than 0.25%); medium carbon steel in the Bay (C less than 0.25 ~ 0.60%); C. High carbon steel (C < 0.60%).
(2) alloy steel: low alloy steel (total alloy element less than 5%) B. Alloy steel (alloy content > 5 ~ 10%) C. High alloy steel (total alloy element content > 10%.
Carbon steel pipe advantages:
Carbon steel has high strength, ductility and toughness, and low cost. It is used for heavy-duty components. The total amount of gold is less than 5%, and it has great impact toughness, and the better mechanical performance casting low alloy steel can be obtained by heat treatment. The quality of the parts and the service life can be reduced.
The advantages of alloy steel:
Except for iron containing steel, only containing carbon steel, carbon steel, other silicon, sulfur, phosphorus and other impurities, 45 steel can be made of ordinary structural steel and 65 steel can be used as ordinary spring steel and tool steel. Besides chromium, manganese, molybdenum, titanium, tungsten, vanadium, niobium, boron, silicon and nickel alloy steel, the required properties, such as high temperature, high elasticity and wear resistance, are achieved. High strength, high toughness and so on. The hardness, wear resistance, hardenability and corrosion resistance of alloy steel are better than those of carbon steel. In the mechanical parts that are widely used for carbon steel.
Comparison of carburizing speed
All the carbide forming elements (titanium, chromium, molybdenum, etc.) increase the carbon concentration on the surface of the carburized layer, while the non carbide forming elements (silicon, aluminum and nickel) will reduce the carbon concentration layer on the diffusion surface. However, the influence of these alloy elements is not always the same, and the content of the alloy elements and carbon elements in the same grade carbon steel or alloy steel is not necessarily the same.
