What is the relative permeability of steel?

The relative permeability of steel can vary significantly depending on the type of steel and its specific composition.

Ferritic and Martensitic Stainless Steels

These types of steels are ferromagnetic and have relatively high permeability. For example:

• Ferritic stainless steel (annealed): Relative permeability ranges from 1000 to 1800124.
• Martensitic stainless steel (annealed): Relative permeability ranges from 750 to 95012.

Austenitic Stainless Steels

Austenitic stainless steels are generally non-magnetic and have a relative permeability close to 1, similar to that of free space.

• Relative permeability is around 1.02 to 1.05, and it can slightly increase with cold work hardening but remains low45.

Electrical Steel

Electrical steel, often used in transformers and other electrical applications, has a high relative permeability.

• Relative permeability ranges from 2000 to 38,00012.

Carbon Steel

Carbon steel also exhibits ferromagnetic properties.

• Relative permeability can be around 1002.

In summary, the relative permeability of steel is highly dependent on its specific type and composition, ranging from near 1 for austenitic stainless steels to several thousand for ferritic, martensitic, and electrical steels.