304 stainless steel is often used as the inner layer (i.e. directly in contact with water) due to its excellent corrosion resistance. 201 stainless steel cannot be used as the inner layer due to its poor corrosion resistance, and is often used as the outer layer of the insulation water tank. However, 201 is cheaper than 304, and is often used by some unscrupulous merchants as 304. The service life of stainless steel water tanks made of 201 stainless steel is extremely short, and it can often be corroded by water in 1-2 years, leaving safety hazards for users.
Here is a simple way to identify these two materials:
1. Specifications: Commonly used stainless steel plates are divided into two types: 201 and 304. In fact, the composition is different. 304 is of better quality, but the price is expensive, and 201 is worse. 304 is an imported stainless steel plate, and 201 is a domestic stainless steel plate.
2. 201 is composed of 17Cr-4.5Ni-6Mn-N, which is a Ni-saving steel and an alternative to 301 steel. It is magnetic after cold processing and is used in railway vehicles.
3. 304 is composed of 18Cr-9Ni, which is the most widely used stainless steel and heat-resistant steel. It is used in food production equipment, chemical equipment, nuclear energy, etc.
4. 201 has a high manganese content, and the surface is very bright with a dark luster. It is easy to rust because of the high manganese content. 304 contains more chromium, and the surface is matte and does not rust. The two are compared together. The most important thing is the difference in corrosion resistance. The corrosion resistance of 201 is very poor, so the price is much cheaper. Because 201 contains less nickel, the price is lower than that of 304, so the corrosion resistance is not as good as that of 304.
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5. The difference between 201 and 304 is the nickel content. And the price of 304 is relatively expensive now, but 304 can at least guarantee that it will not rust during use. (Stainless steel 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 is a high-manganese stainless steel with greater hardness than 304, high carbon and low nickel.
7. Different ingredients (201 and 304 stainless steel are mainly distinguished by carbon, manganese, nickel and chromium content)
Steel No. Carbon (C) Silicon (Si) Manganese (Mn) Phosphorus (P) Sulfur (S) Chromium (Cr) Nickel (Ni) Molybdenum (Mo) Copper (Cu)
AISI (304) ≤0.08 ≤1.00 ≤2.00 ≤0.045 ≤0.03 18-20 8-10
AISI (201) ≤0.15 ≤1.00 5.5-7.5 ≤0.05 ≤0.03 16-18 3.5-5.5
Post time: Jan-06-2025
