Difference between grade 304 and grade 202 stainless steel

1, different specifications

Commonly used stainless steel plate is divided into 201 and 304 stainless steel plate two models, the actual composition is different, 304 quality is better but more expensive, 201 is worse. 304 is imported stainless steel plate, 201 is domestic stainless steel plate.

2, the composition is different

201 is composed of 17Cr-4.5Ni-6Mn-N, which is an alternative to 301 steel. It is magnetic after cold working and is used for railway vehicles.

304 consists of 18Cr-9Ni and is the most widely used stainless and heat-resistant steel. It is used in food processing equipment, Weston chemical equipment and nuclear energy. Molybdenum also promotes the precipitation of intermetallic phases in austenitic stainless steels, such as σ phase, κ phase and Raffles phase, which adversely affect corrosion resistance and mechanical properties. In particular, the properties of steel are reduced in plasticity and toughness. In order to maintain the single austenite organisation of austenitic stainless steels, as the molybdenum content of the steel increases, the content of austenite-forming elements (nickel, nitrogen and manganese, etc.) should be increased accordingly to maintain a balance between ferrite and organisation. Austenitic elements in steel.

3, the elements are different

201 is high in manganese, the surface is very bright with dark light, high manganese content is easy to rust.

304 contains more chromium, the surface is dull and does not rust. The two are put together for comparison. The most important thing is that the corrosion resistance is not the same, 201 has very poor corrosion resistance, so the price will be much lower. And because 201 has a low nickel content, the corrosion resistance is not as good as 304.

4.201 and 304 is nickel content

And now 304 is more expensive, usually close to 50,000 tonnes, but 304 can at least guarantee that it will not rust during use. (Experiments with agents)

5 stainless steel is not easy to rust, because the formation of chromium-rich oxides on the surface of the steel body can protect the steel body, 201 material belongs to high manganese stainless steel, hardness is higher than 304, carbon low nickel. Inherent intergranular corrosion This material does not contain titanium and niobium and has a tendency to intergranular corrosion. Intergranular corrosion can be reduced by adding titanium and niobium for stabilisation. In the air or chemical corrosive media can resist corrosion of a high-alloy steel, stainless steel has a beautiful surface and good corrosion resistance, do not have to go through electroplating and other surface treatments, but to play the inherent surface properties of stainless steel, used in many aspects of the steel, usually called stainless steel.