Austenitic stainless steels are characterized as:

Austenitic stainless steels are characterized as non-magnetic due to their face-centered cubic (FCC) crystal structure. This structure occurs in austenitic grades of stainless steel, such as those containing significant amounts of nickel and chromium. The arrangement of atoms in this structure does not allow for the alignment of magnetic domains, which results in non-magnetic properties.

While some stainless steels may exhibit magnetic properties, particularly when they undergo work hardening or when they are cold worked, austenitic stainless steels are generally considered non-magnetic in their annealed state. This characteristic is important in various applications, particularly in industries where magnetic properties could interfere with operations or where non-magnetic materials are preferred.

The other characteristics mentioned in the alternatives are either not applicable or do not define austenitic stainless steels specifically. For example, while some steels can be corrosive in certain environments, austenitic stainless steels are typically known for their excellent corrosion resistance. They are also not recognized for being brittle, as they usually possess good ductility and toughness. Lastly, the magnetic properties would lead some to conclude that there might be specific circumstances under which certain stainless alloys are magnetic, but this does not apply broadly to equally characterize austenitic stainless steels.