What kind of stainless steel is good for automobile exhaust pipes
The materials used to make automobile exhaust pipes are diverse and dazzling. The exhaust pipe is installed between the engine exhaust manifold and the muffler to make the entire exhaust system flexibly connected, thereby reducing vibration and noise, facilitating installation, and prolonging the life of the exhaust muffler system.
The materials used for the exhaust pipes also changed from the original iron and galvanized ones to the stainless steel materials used today. Most exhaust pipes currently on the market are made of stainless steel. Among them are 2 series, 3 series and 4 series stainless steel. The point is here, they are all made of stainless steel. How to distinguish 2 series, 3 series and 4 series stainless steel? Which stainless steel exhaust pipe is of better quality?
1. Comparison of steel properties:
2 series stainless steel: Take 201 stainless steel as an example.
201 stainless steel has certain acid and alkali resistance and is a high-quality material for the production of various watch cases and watchband bottom covers. Mainly used to make decorative tubes, industrial tubes and some shallow stretched products.
The biggest advantage of this kind of stainless steel is its good punch ability. The disadvantage is that it is not resistant to high temperatures, and the acid and alkali resistance is relatively poor.
3 series stainless steel: Take 301 and 304 stainless steel as examples.
301 and 304 stainless steel are a kind of universal stainless steel. The main difference between them is the nickel content.
The nickel content of 301 is about 6.0; the nickel content of 304: about 8.0; the difference in nickel content directly causes the acid corrosion resistance of 304 stainless steel to be better than that of 301 stainless steel. Of course, the cost is also higher than that of 301.
301 stainless steel is mainly used for standard parts, trains, aircraft, conveyor belts, and other weak corrosion-resistant products;
The use of 304 stainless steel is much larger than that of 301. When the 301 stainless steel use can be satisfied. 304 stainless steel is also used in medical appliances, building materials, food industry, ship parts and other products that require acid, alkali, salt, and high corrosion resistance. By the way, 304 stainless steel is a nationally recognized food-grade stainless steel.
4 series stainless steel: Take 409 stainless steel as an example.
409 stainless steel, the cheapest model (British and American), is usually used as a car exhaust pipe, it is ferritic stainless steel.
409 stainless steel has the advantage of low cost. The disadvantage is that the nickel content is extremely low, only ≤0.50. Therefore, the acid and alkali corrosion resistance is low, and because it belongs to the ferrite series, it is easy to be attracted by the magnet. It is called stainless iron in the industry.
二: How to distinguish.
It is actually very simple to distinguish. Only two tools are used. One is a magnet; the other is a stainless steel detection fluid.
As mentioned above. Because the 4 series belong to the ferrite series, it is easy to be attracted by the magnet, so it is the easiest to identify; 2 series and 3 series can only use stainless steel detection liquid. Drop the stainless steel detection liquid on the two stainless steel materials within 5 seconds. It is the 2 series stainless steel that quickly turns red, and the 3 series stainless steel does not undergo any changes.
Summary: Different stainless steel models have different performances. From the comparison of corrosion resistance, high-temperature resistance, oxidation resistance, weldability, and comprehensive performance, it is concluded that 304 stainless steel has the most superior performance, followed by 301, 409, and 201 stainless steel.