First of all, let's talk about what stainless steel is. It refers to steel that is resistant to corrosion in the atmosphere and weakly corrosive media. If the corrosion rate is less than 0.01mm/year, it is considered to be "completely resistant to corrosion"; if the corrosion rate is less than 0.1mm/year, it is considered to be "corrosion resistant".
Stainless steel models in China are represented by element symbols plus numbers, such as: 1Cr18Ni9, 0Cr18Ni9, 00Cr18Ni9, 1Cr17, 3Cr13, 1Cr17Mn6Ni5N, etc. The numbers represent the corresponding element content.
Common stainless steel models are commonly represented by digital symbols, including 200 series, 300 series, and 400 series, which are the representation methods of the United States, such as 201, 202, 302, 303, 304, 316, 410, 420, 430, etc. The American Iron and Steel Institute is Use three digits to designate various standard grades of malleable stainless steel. in:
①Austenitic stainless steel is marked with numbers of 200 and 300 series.
② Ferritic and martensitic stainless steels are represented by numbers in the 400 series. For example, some of the more common austenitic stainless steels are designated 201, 304, 316 and 310.
③The ferritic stainless steel is marked with 430 and 446, and the martensitic stainless steel is marked with 410, 420 and 440C, duplex (austenite-ferrite).
④Stainless steel, precipitation hardening stainless steel and high alloys with iron content less than 50% are usually named by patent names or trademarks.
Functional difference:
304 is a versatile and widely used stainless steel material, which is widely used to make equipment and parts that require good comprehensive properties (corrosion resistance and formability). Withstands general rust in construction, resists attack by food processing media (but may corrode at elevated temperatures containing concentrated acids and chlorides), and resists organic compounds, dyes, and a wide variety of inorganic compounds. 304L type (low carbon), good resistance to nitric acid, and durable to medium temperature and concentration of sulfuric acid, widely used as liquid gas storage tank, used as low temperature equipment (304N), appliances and other consumer products, kitchen equipment, hospital equipment, transportation Tools, waste water treatment plants.
Type 430 has a lower alloy content than Type 304 and is used for high polishing decorative purposes in mild atmospheres, as well as for nitric acid and food processing equipment.
The difference between stainless steel 201 and 304:
1. Specifications: Commonly used stainless steel is divided into two types: 201 and 304. The actual composition is different. 304 is better in quality, but expensive, and 201 is worse.
2. The composition of 201 is 17Cr-4.5Ni-6Mn-N, which is a Ni steel grade and an alternative to 301 steel. It is magnetic after cold working and is used in railway vehicles.
3. The composition of 304 is 18Cr-8Ni, which is the most widely used stainless steel and heat-resistant steel. Used in food production equipment, Xitong chemical equipment, nuclear energy, etc.
4. 201 is high in manganese, the surface is very bright with dark and bright, and high in manganese is easy to rust. 304 contains more chromium, and the surface is matte and does not rust. The two are compared together. The most important thing is that the corrosion resistance is different. The corrosion resistance of 201 is very poor, so the price is much cheaper. And because 201 contains low nickel, the price is lower than that of 304, so the corrosion resistance is not as good as that of 304.
5. The difference between 201 and 304 is the nickel content. And the price of 304 is more expensive now, but 304 can at least guarantee that it will not rust during use. (Potion can be used for experiments)
6. Stainless steel is not easy to rust because chromium-rich oxides are formed on the surface of the steel body to protect the steel body. 201 material belongs to high manganese stainless steel, which is higher in hardness, higher in carbon and lower in nickel than 304.
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