Automotive steel refers to a special type of steel used in automobile manufacturing. The classification of automotive steel is mainly based on its chemical composition, mechanical properties and uses. According to different requirements, automotive steel can be divided into the following categories.

1. Structural steel: Structural steel is one of the main categories of automotive steel, which is mainly used in the manufacture of automobile bodies and chassis. Structural steel needs to have high strength and toughness to ensure that the body can effectively absorb energy in the event of a collision and protect the safety of the occupants of the car. Common structural steels include low carbon steel, medium carbon steel and high carbon steel.

2. Strengthened steel: Strengthened steel is a kind of steel that is strengthened by heat treatment or cold deformation and other processes for ordinary structural steel. It has high strength and hardness, which can improve the tensile strength and fatigue resistance of automobiles. Common reinforced steels include low-alloy reinforced steels, high-strength low-alloy steels and austenitic reinforced steels.

3. Stainless steel: Stainless steel has good corrosion resistance and aesthetics, and is widely used in automotive manufacturing, such as exterior trim parts, exhaust pipes and parts. Stainless steel can be divided into several categories such as austenitic stainless steel, ferritic stainless steel and duplex stainless steel, each category has different characteristics and application range.

4. High-strength steel: With the increasing demand for lightweight in the automotive industry, high-strength steel has gradually become an important part of automotive steel. High-strength steel has higher strength and lower density, which can reduce the weight of the vehicle and improve fuel economy and driving performance. Common high-strength steels include high-strength low-alloy steels, dual-phase steels and multiphase steels

5. Cold formed steel: Cold formed steel is a special steel specially used for cold stamping of automobiles. It has good plasticity and machinability, and can meet the manufacturing needs of complex auto parts. Cold formed steel can be divided into low carbon cold formed steel, medium carbon cold formed steel and high carbon cold formed steel, etc.

6. High temperature alloy steel: High temperature alloy steel is mainly used in the manufacture of high temperature parts such as engine cylinder block, crankshaft and turbine. It has good high temperature resistance and oxidation resistance, and can maintain stable mechanical properties in high temperature environment. Common high temperature alloy steels include aluminum alloys, nickel-based alloys and titanium alloys.

7. Other special steel: In addition to the above common types of automotive steel, there are some other special purpose automotive steel. For example, wear resistant steel is mainly used in automotive engine cylinder liner and piston ring and other damaged parts: conductive and thermal steel is mainly used in automotive batteries and radiators and other parts: bulletproof steel is mainly used in the manufacture of military vehicles, etc.

All in all, automotive steel can be divided into several categories according to its chemical composition, mechanical properties and uses. Each category of automotive steel has different characteristics and applications, but all play a key role in ensuring the safety, reliability and economy of the vehicle. With the continuous development of automotive technology, the demand for new automotive steel materials is also increasing, which will promote the further development and innovation of the automotive steel industry.