That is, the crystal structure has an atom on each corner of the cube, and an atom in the middle of each face. and ferrite stainless steel is the opposite, it is characterized by the body heart cube structure.
Nickel is one of the most commonly used elements in the production of this crystalline structure, but because of the lack of nickel after World War II, efforts have been made to reduce the use of metals. This led to the replacement of nickel, which is used to produce some corrosion-resistant austenitic stainless steel, by other elements, resulting in the emergence of 200-series stainless steel.
Nitrogen alloys in 200-series stainless steel will also form a facial heart cube structure, leading to harmful chromium nitride and increasing gas porosity. Adding manganese allows more nitrogen to be added safely, but nickel cannot be completely removed from 200-series stainless steel. Therefore, 200 series stainless steel is characterized by its nitrogen and manganese content.
In the 80 's, the production and demand of low nickel stainless steel surged, the price of nickel continued to rise, but also to promote the development of 200 series stainless steel. Asia is now the main source and place of consumption for 200 series of steel. The corrosion resistance of 200 series stainless steel is lower than that of 300 series stainless steel, which prevents point corrosion in environments with high moisture and chlorine content and gap corrosion, causing the liquid and acidic environment to stagnate. This is because in order to reduce the nickel content, it will also reduce chromium content and corrosion resistance.
The 200-series stainless steel has excellent impact resistance and toughness, even at low (or even low temperature) temperatures. They are usually harder and stronger than 300 series steels, mainly due to their higher nitrogen content, which is the role of nitrogen reinforcement. Because they are austenite, stainless steel in the 200 and 300 series is not magnetic. Although austenitic stainless steel is more expensive than its ferrite steel, 200-series stainless steel is still cheaper than 300-series stainless steel due to its lower nickel content. However, the molding (ductility) of 200 series stainless steel is lower than that of 300 series stainless steel (although this can be improved by adding copper).
In terms of application, the application range of 200 series stainless steel is narrower than that of 300 series stainless steel because of the low corrosion resistance of the material. It is not recommended to be used in a chemical environment, but has entered many household items. Some applications of the 200 series Stainless steel include: Dishwashers and washing machines, cutlery and cooking utensils, internal water tanks, indoor and non-critical outdoor buildings, food and beverage equipment, cars (structures and decorations).