What makes austenitic stainless steel non-magnetic?

What makes austenitic stainless steel non-magnetic?

• A. Addition of nickel over 6%
• B. Addition of chromium over 12%
• C. Addition of vanadium over 1%
• D. Addition of carbon over 0.5%

Answer: (A)

Magnetism in stainless steels depends on the crystal structure that is stable at room temperature. Austenitic steels have a face-centered cubic structure, which is non-magnetic, while ferritic or martensitic structures are magnetic. Nickel acts as an austenite stabilizer: when its content is around 6% or more, the austenitic phase becomes stable at room temperature, so the material behaves non-magnetically. Chromium on its own supports corrosion resistance and can promote ferritic (magnetic) structures if nickel isn’t present, but it doesn’t by itself eliminate magnetism. Vanadium and carbon influence strength and carbide formation, not the fundamental phase that governs magnetic behavior. Keep in mind that heavy cold-working can introduce some magnetic response by forming martensite locally, but the overall non-magnetic nature of austenitic stainless steel primarily comes from nickel-stabilized austenite.

Magnetism in stainless steels depends on the crystal structure that is stable at room temperature. Austenitic steels have a face-centered cubic structure, which is non-magnetic, while ferritic or martensitic structures are magnetic. Nickel acts as an austenite stabilizer: when its content is around 6% or more, the austenitic phase becomes stable at room temperature, so the material behaves non-magnetically. Chromium on its own supports corrosion resistance and can promote ferritic (magnetic) structures if nickel isn’t present, but it doesn’t by itself eliminate magnetism. Vanadium and carbon influence strength and carbide formation, not the fundamental phase that governs magnetic behavior. Keep in mind that heavy cold-working can introduce some magnetic response by forming martensite locally, but the overall non-magnetic nature of austenitic stainless steel primarily comes from nickel-stabilized austenite.