The difference between austenitic and ferritic stainless steel

The main distinction between austenitic stainless steel and ferritic stainless steel lies in their respective structures and properties.

Austenitic stainless steel is an organization that remains stable only at temperatures higher than 727°C. It exhibits good plasticity and is the preferred structure for most steels undergoing pressure processing at elevated temperatures. Additionally, austenitic steel is non-magnetic.

Ferrite is a solid solution of carbon dissolved in α-iron, often symbolized as F. In stainless steel, "ferrite" refers to the solid solution of carbon in α-iron, characterized by its limited carbon solubility. At room temperature, it can only dissolve up to 0.0008% carbon, reaching a maximum carbon solubility of 0.02% at 727°C, while maintaining a body-centered cubic lattice. It is commonly represented by the symbol F.

The difference between austenitic and ferritic stainless steel

On the other hand, ferritic stainless steel refers to stainless steel predominantly composed of a ferritic structure during use. It contains chromium in the range of 11% to 30%, featuring a body-centered cubic crystal structure. The iron content of stainless steel is unrelated to whether it is classified as ferritic stainless steel.

Due to its low carbon content, ferritic stainless steel exhibits properties similar to pure iron, including excellent plasticity and toughness with an elongation rate (δ) of 45% to 50%. However, its strength and hardness are relatively low, with a tensile strength (σb) of approximately 250 MPa and a Brinell hardness (HBS) of 80.


Post time: Dec-25-2023