Types of Steel


There are so many types of steel in the world. Different types of steel would be used in different places. That depends on what it really is for the types and what properties are it. The types of steel and its introduction as below.

Carbon Steel

Carbon steel is an iron-carbon alloy. Its carbon content is less than 2%. It also has a small quantity of silicon, manganese, sulfur and phosphorus besides carbon. People always classify it for carbon structural steel, carbon tool steel and free-cutting structural steel by applications. And the carbon structural steel has two branches. They are building structural steel and structural steel for machine production. And also be divided into low carbon steel (ωc ≤ 0.25%), medium carbon steel (ωc = 0.25% – 0.6%) and high carbon steel (ωc > 0.6%). Usually, if the carbon content is bigger, then the hardness and strength also become higher. But the plasticity would get lower.

Carbon Structural Steel

Usually, It does not through heat treatment. Just use it directly at the original factory status. And the Q195 steel, Q215 steel, Q235 steel have great welding performance, plastic nature and toughness. It always is used to make thin plates, steel bars, welded steel pipes. And the fittings of mechanical bolts, inside screws and etc. The Q255 steel and Q275 steel also have high strength, high plasticity, high toughness and can be welded very well. They are good material for gears, connecting bar and etc.

Free Cutting Structural Steel

It is made by adding some elements which could make steel become brittle. Then the steel is easy to be cut during the processing. It is good for the efficiency of steel cutting and raises cutting tools useful time. And the main element is sulfur. However, people usually adding the lead, antimony and bismuth to the ordinary low-alloy free cutting structural steel. It’s sulfur content is about 0.08%-0.30%. And the manganese element is 0.60%-1.55%. The sulfur and manganese are involved as the form of manganous sulfide. It has great lubricating efficiency to make the steel become easier to be processed.

The steel must have the chemical element of iron, carbon, silicon, manganese, phosphorus, sulfur. But it also has some alloy elements. Such as silicon, manganese, molybdenum, nickel, chromium, vanadium, titanium, niobium, boron, lead and etc. Alloy steel is made by adding some alloy elements base on the common steel. And alloy steel can be divided into 8 groups: Alloy structural steel, Spring steel, Bearing steel, Alloy tool steel, High speed tool steel, Stainless steel, Silicon steel for electricians.

Engineering Structural Alloy Steel

It means the main fields are engineering and building structures for this steel. Its alloy element content is low. But the production and demand for it are large in the world.

Machine Structural Alloy Steel

It is usually used for the manufacture of machines and the fittings of the machine. It is made by adding one and several alloy elements to high-quality carbon steel. And the action will make the strength, toughness and hardenability of steel get better. It needs to heat treatment process before the use.

Alloy Structural Steel

The carbon content of alloy structural steel is lower than carbon steel. It’s content usually at the range of 0.15%-0.50%. It is not easy to deform or cracked. And it is widely used in the manufacture of automobile, ship and etc.

Alloy Tool Steel

Alloy tool steel has multiple alloy elements. Such as silicon, chromium, tungsten, molybdenum, vanadium and etc. It is easy to become harder after quenching. And it is not easy to get deformation and cracking. It also can be used to manufacture cutting tools. And the carbon content of it would be different because of different application. The carbon content of common alloy tool steel is at the range of 0.5%-1.5%. But the content of hot work tool steel is lower and the range is 0.3%-0.6%.

High Speed Tool Steel

It is a tool steel with high elements of carbon and alloy. The carbon content is 0.7%-1.4%. And it has great red hardness. At the condition of high speed cutting, the temperature would keep at the range of 500-600℃ to make sure the machinability as well.

Spring Steel

It needs to sustain impacts, vibration and etc during the work. So it is required to have great intensity of tension, elastic limit, fatigue strength and etc. The carbon content of alloy spring steel is lower. Because it depends on the silicon element to raise the properties.

Bearing Steel

It is good material for ball bearing, bearing ring and etc. The bearing sustains huge pressure and friction. So it must have the great hardness, wear resistance and elastic limit. The requirement for bearing steel is very strict for the parts of chemical distribution, the contents of metal elements and etc.

Electrical Silicon Steel

It is used to make the electrical steel silicon steel sheet. Silicon steel sheet is the most popular product at the production of electric machinery and transformer. There are two types of it. Including low silicon steel and high silicon steel. And the content of silicon of low silicon steel is 1.0%-2.5%. It is usually used to make electric machinery. But the high silicon steel is 3.0%-4.5%. And it is good material for the transformer. Their carbon content usually at the range of 0.06%-0.08%.

Hull Steel

It is used to make the ship. It is required to has good welding performance because of the structure of the ship. And also the strength, toughness and decay resistance need to be excellent. In the past, people usually use low carbon steel as material to make it. But in recent times, people use common low alloy steel to instead it.

Bridge Steel

It is the material of the bridge of railway and highway. It needs to handle the impulse load from the car. So it must have great strength, toughness. And it’s surface quality must be great.

Boiler Steel

It is the best material to manufacture the superheater, vapor pipe and etc. The boiler steel must have good welding properties, scale resistance and etc. Making the high-pressure boiler need to use austenitic heat-resistance steel as the material.

Stainless Steel

It is alloy steel. The atmospheric corrosion resistance of it is very well. Usually, the steel which has the chromium content is bigger than 12%, then it will have the same properties as stainless steel. If you have another information of types of steel, please add a comment or contact us.