In the past ten years, stainless steel has been widely used in public transportation vehicles such as buses, subways, and high-speed railway vehicles in our country. The lightweight and demanding development of rail vehicles will be the main development direction of rail vehicles in the future.Stainless steel not only has corrosion resistance, but also good physical properties and surface quality. It has been widely used in automobile manufacturing. At present, the main application components are the following categories：

1. Stainless steel for exhaust systems: Most of them are ferritic stainless steel, which is the main component of automotive stainless steel applications.409L, 436L, etc. are commonly used stainless steel grades.From the point of view of economy and practicality, some European and American automobile exhaust systems often use 0Cr11Ti ferritic stainless steel, and Japan basically uses 13Cr~17Cr ferritic stainless steel and its improved type.

2. Stainless steel for automobile fuel tanks: In addition to the risk of fuel leakage, the fuel tanks made of stainless steel have good corrosion resistance and good forming properties. In addition, the coating process can be omitted or simplified, and it is easy to recycle.304L, JFE-SX1, etc. are commonly used stainless steel grades.

3. Stainless steel for automobile frames: The combination of the combined automobile frame design and the excellent performance of stainless steel materials can make the manufactured automobile have good impact resistance, light weight, high safety and reliability, and long life. In addition, such a frame can be completely recycled.409L, 3Cr12, 304L, etc. are all commonly used stainless steel grades.

4. Automotive stainless steel parts: there are mainly stainless steel sealing rings and heat exchangers. The sealing rings are generally made of 301 stainless steel. The heat exchangers generally use stainless steel materials such as SUS304, SUS430 and SUS409L. Cr-Ni austenitic stainless steel is also used in some parts; 0Cr17, 0Cr18 Ni9 are used for oil cooler plate heat exchangers, and 0Cr17 can generally be used for headlight guards, large bus handrails, safety railings, etc.

5. Stainless steel for automobile decoration: stainless steel inserts, antennas, wheel covers, etc. are used on small cars, and stainless steel is also used on the handrails, safety railings, and handrails of large buses and vehicles.In order to reduce costs, the rearview mirrors are mainly made of SUS430J1L stainless steel. The rearview mirrors of some expensive cars are made of SUS436J1L stainless steel. The wipers of automobiles are mostly made of SUS430, SUS304, SUS301, etc., and the headlight guards are made of SUS430 and other steel grades.Stainless steel is also often used for safety devices on cars.For example, the seat belt tensioner adopts SUS301 stainless steel, the airbag sensor and booster pump mainly use SUS304 and SUS304L stainless steel, and the ABS sensor ring adopts SUS434, SUS444 and other steel grades.

6. Car frame or overall car shell: Car frame or overall car shell made of stainless steel containing 11% to 12% Cr, commonly used grades are 00Cr11Ti, 0Cr11Ni4Ti, 00Cr12NiTi and so on.Some countries have successively used stainless steel in large buses, coal transports, urban subway vehicles, etc.