At present, the stainless steel commonly used in kitchen equipment mainly includes 201 and 304. 201 stainless steel is cost-effective, cheap, but easy to rust; 304 stainless steel is the most widely used stainless steel material, not easy to rust, good quality, the price is also higher than 204.
There is almost no difference between 201 stainless steel plate and 304 stainless steel plate, which can hardly be distinguished by naked eyes. Here are some methods to distinguish them.
1. Specification: commonly used stainless steel plate is divided into 201 and 304 two models, the actual composition is different, 304 good quality, but the price is expensive, 201 poor. 304 is imported stainless steel plate, 201 is domestic stainless-steel plate.
2. The composition of 201 is 17cr-4.5ni-6mn-n, which is the substitute of 301 steel. It has magnetism after cold working and is used in railway vehicles.
3. The composition of 304 is 18cr-9ni, which is the most widely used stainless steel and heat-resistant steel. For food production equipment, chemical equipment, nuclear power, etc.
4. 201 stainless steel plate has high manganese content, bright surface with dark brightness, high manganese content is easy to rust, manganese is also harmful to human nervous system, so 201 stainless steel plate is not suitable for food grade equipment. 304 contains more chromium, the surface is matte, not rusty. 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. Because 201 has low nickel content, the price is lower than 304, so the corrosion resistance is not as good as 304. And 304 stainless steel safety belongs to the edible grade material, at present, the edible grade stainless steel is 304 stainless steel plate and above.
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 in the process of use. (stainless steel solution can be used for experiment)
6. The reason why stainless steel is not easy to rust is that chromium rich oxide formed on the surface of steel body can protect the steel body
7. Different composition (mainly from carbon, manganese, nickel, chromium to distinguish 201 and 304 stainless steel)
Steel grade 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
Therefore, 304 stainless steel is the best material for the production of kitchen equipment. However, many unscrupulous businesses in the market now use 201 stainless steel to fill 304 stainless steel, which is difficult to distinguish when accepting. Therefore, when purchasing stainless steel kitchenware and kitchen equipment, first of all, do not choose brands lower than the industry price.