1. Different specifications
The commonly used stainless steel plates are divided into two types: 201 and 304. There are two types of stainless steel plates, which are actually different in composition. 304 is of better quality but more expensive, while 201 is of poorer quality. 304 is an imported stainless steel plate, while 201 is a domestic one.

2. Different ingredients
Steel grade 201 is 17Cr-4.5Ni-6Mn-N, which belongs to Ni steel and is a substitute for 301 steel. It has magnetic properties after cold working and is used in railway vehicles.
The composition of 304 steel is 18Cr-9Ni. It is the most widely used stainless steel and heat-resistant steel, and is applied in fields such as food production equipment, chemical equipment, and nuclear energy. Molybdenum can also promote the precipitation of intermetallic compounds such as σ phase, κ phase and Laves phase in austenitic stainless steel, which has an adverse effect on the corrosion resistance and mechanical properties of the steel, especially leading to a decrease in plasticity and toughness. In order to maintain a single austenitic structure in austenitic stainless steel, as the molybdenum content in the steel increases, the content of austenite-forming elements (such as nickel, nitrogen and manganese) must also increase accordingly to maintain the balance between ferrite and austenite-forming elements in the steel.

3. Different elements
201 has a relatively high manganese content, a very bright surface, and a dark to bright color. A high manganese content makes it prone to rust.
304 has a relatively high chromium content, a matte surface and will not rust. When comparing the two together, the most significant difference lies in their corrosion resistance. The corrosion resistance of 201 is very poor, so its price is much lower. Moreover, due to the lower nickel content of 201, its corrosion resistance is not as good as that of 304.

The difference between 4.201 and 304 lies in the nickel content
Moreover, the price of 304 is currently quite high, generally approaching 50,000 yuan per ton. However, 304 can at least ensure that it will not rust during use. Experiments can be conducted with medicinal water.

5. Stainless steel is not prone to rust because chromium-rich oxides form on the surface of the steel body, protecting it. Material 201 is a high-manganese stainless steel with a higher hardness than 304, featuring high carbon and low nickel content. Materials without titanium and niobium have a tendency to undergo intergranular corrosion. Adding titanium and niobium, combined with stabilization treatment, can alleviate intergranular corrosion. A kind of high-alloy steel that can resist corrosion in air or chemical corrosive media. Stainless steel has an attractive surface and excellent corrosion resistance. It does not require surface treatments such as electroplating and can fully utilize its inherent surface properties. It is a widely used type of steel and is usually referred to as stainless steel.