What is carbon steel?
Mainly refers to the carbon content of less than 1.3% by mass and does not contain specially added alloying elements. Sometimes called plain carbon steel or carbon steel.
According to the C content of steel, it can be divided into low carbon steel, medium carbon steel and high carbon steel.
1, low carbon steel
Also known as mild steel, carbon content from 0.10% to 0.30% low carbon steel is easy to accept all kinds of processing such as forging, welding and cutting, often used in the manufacture of chains, rivets, bolts, shafts and so on. Low carbon steel is generally rolled into Angle steel, channel steel, I-steel, steel pipe, steel belt, steel plate, used for the production of various building components, containers, boxes, furnace and agricultural machinery and tools. High quality low carbon steel rolled into thin sheet, the production of automobile cab, hair I machine cover and other deep drawing products; Also rolled into bars, used to make strength requirements of mechanical parts.
2, medium carbon steel
Carbon content (C: 0.25% < C ≤ 0.6%) In addition to carbon can also contain a small amount of manganese (0.70% ~ 1.20%). Its hot working and cutting performance is good, but its welding performance is poor. The strength and hardness are higher than low carbon steel, while the plasticity and toughness are lower than low carbon steel. So in a variety of uses of moderate strength level, medium carbon steel is the most widely used, in addition to as a building material, but also a large number of used in the manufacture of various mechanical parts. Medium carbon steel is mainly used to manufacture high strength moving parts, such as air compressor, pump piston, steam turbine impeller, heavy machinery shaft, worm, gear and so on, surface wear resistant parts, crankshaft, machine tool spindle, roller, locksmith tools and so on.
3, high carbon steel
Carbon content (C: 0.6% ~ 1.3%) is often called tool steel, with carbon content from more than 0.60% to 1.70%, which can be hardened and tempered. Hammers, crowbars, etc. are made of 0.75% carbon steel; Cutting tools such as drills, taps, reamers, etc. are made from 0.90% to 1.00% carbon steel. The higher the carbon content, the higher the hardness and strength, but the plasticity decreases.
4. Classification of common steel use
Carbon structural steel for boiler: Q245R
Carbon steel for welding gas cylinders: HP235, HP265, HP295
Carbon structural steel for Bridges: Q235q
Steel for Boilers and pressure vessels: 20R, 20g, 20HR (nuclear grade)
Carbon steel for pipeline: L245, L175, L290
Rail steel: U71, U71Mn
Automotive steel: 370L, 420L