Is Stainless Steel Magnetic?

If asked “is stainless steel magnetic?” we are likely to get a variety of responses. Some will say yes they are magnetic as it contains iron while some will say they believe it to be a non-magnetic material.

The right answer that most people fail to deliver is, stainless steels are of two kinds. One is magnetic and the other one non-magnetic. They are alloys that contain iron particles in them and are very well known as corrosion resistants’.

Here is the information about four types of magnetic stainless steels.

• Ferritic stainless steel

  

  Ferrite is an iron compound present in ferritic stainless steel’s chemical composition. These are high chromium magnetic stainless steels with low carbon content. The chromium content is higher than that of martensitic stainless steels (11 to 30 % chromium in solid solution). Defined by a BCC (body-centered cubic) grain structure, they are very ductile and can resist corrosion and stress cracking. They are highly popular in kitchenware and manufacturing industry equipment and are also utilized in the manufacture of street furniture, electrical cabinets, fridge cabinets, and water tanks, etc. These are typically required to create corrosion resistant or stress corrosion resistant non-structural forms. Ferritic steels are not hardenable and cannot be straightened by any heat treatments. They can only be melted by annealing. There are five types of ferritic stainless steel each having different chemical compositions. They are cost-friendly and weldable and have a zero-nickel content.

• Martensitic Stainless Steels:
  

  Martensitic Stainless Steel invented by Brearly and Krupp Stahl right after the First World War comes under magnetic steel and are the hardest structural component in steel. The martensitic stainless steel structures are body-centered tetragonal (BCT), and so they fall under the hard ferromagnetic group. The chemical compound consists of a unique crystal structure that can be ferromagnetic if iron is present. By heat treatments like quenching and tempering, they can be hardened. They contain no nickel and are straight chromium steels (12 to 17% chromium). Martensitic stainless steels are popularly used in tools such as kitchen knives, razors, and clamps. They have extreme strength, resistance, and hardness and are great thermal conductors.

• Duplex Stainless Steel
  
  
  Duplex stainless steel is magnetic steel comprising of a mixture of austenite and ferrite. The ferrite being plentiful makes the Duplex steels magnetic. The name Duplex is given because of the equal presence of these both- Austenite (face-centered cubic lattice) and ferrite (body-centered cubic lattice). If the duplex stainless steel is melted, it solidifies into a complete ferritic structure, and after attaining room temperature, almost half of the structure transforms into an austenitic structure. They are excellent corrosion resistant especially stress corrosion cracking and have great mechanical properties.

  If the duplex stainless steel is melted, it solidifies into a complete ferritic structure, and after attaining room temperature, almost half of the structure transforms into an austenitic structure. Some winning properties are –
  Strength: They are twice stronger than individual austenitic and ferritic steels.
  Ductility: Has better toughness and ductility than ferrite stainless steels.
  Cost: Having very less amount of nickel in the chemical composition makes them affordable than the other stainless steels.

Austenitic Stainless Steel

It is the type of stainless steel that is used most ordinarily in the industry for almost all the stainless steel creations as it can be cast and welded easily. Austenitic stainless steels comprise of austenite alone, making them non-magnetic. They are labeled under non-ferromagnetic. But through heat treatments or hardening, the crystal structure of austenitic steels may attain ferritic compounds partly – making them partially magnetic. Represented by face-centered cubic (FCC) crystal structure- having one atom at every corner of the cube and one in the middle of every face.
Austenitic steels have a low level of carbons and a sufficient quantity of nickel present in its composition, i.e., about 8 % in 18% chromium. Since they are mostly non-magnetic, austenitic stainless steels are not heat treatable. So to improve hardness strength and resistance, they have to be cold worked. Ductility can be developed by quenching or rapid cooling. Another advantage of using this steel is that it can resist high temperatures (-238 °F, -150 °C)
Austenitic stainless steels have a large-scale variety of applications.

• Automotive trim
• Kitchenware and utensils.
• Food and beverage materials
• Industrial tools
• Tanks
• Storage vessels
• Architecture and pharmaceutical equipment.

Why is it important?
Stainless steel industry has become an important industry over time. Our standard of living has developed due to the contributions of stainless steels in the market. They are an integral component of most solid structures we see in our daily life. The strength resistance and ductility have made them an ideal material for a huge range of applications. They are 100 % recyclable, and almost all other industries rely on the stainless steel market, be it construction, food, and beverage, cookware, automotive and much more. Stainless steel is the most powerful solution to a wide spectrum of industries. They are prepared in various forms like plates, coils, rods, foils for both industrial and domestic needs.

Magnetic Stainless steel’s durability, stability and ductility, and low maintenance make it the ideal material for a wide range of purposes. It is 100% recyclable, and a wide range of needs depend on them. Magnetic stainless steels have more applications than non-magnetic stainless steels. They are the most effective solutions as they improve and develop the performance of materials.