Is Stainless Steel Magnetic?
To answer the question, we need to know what stainless steel consists of and how many types of stainless still are there. It is important to know this since we want to know whether stainless steel is magnetic or not.
First of all, stainless steel is steel alloy contains chromium, carbon, and additional elements depending on what it’s rolled into. The percentage of chromium content influences the stainless steel corrosion resistance. The higher the percentage is, the more resistant it gets. Moreover, the additions of molybdenum also increase the level of corrosion resistance.
Due to its corrosion resistance, stainless steel is usually made into cookware, cutlery, surgical tools, construction materials, and so on. It’s easy to be cleaned and sterilized, thus, it’s also used in commercial kitchens and food processing plants.
The Characteristics of Stainless Steel
Stainless steel has certain characteristics, including:
- Resistant to corrosion
Chromium is the most used element that makes stainless steel resistant to corrosion. The percentage of chromium is around 10.5% minimum, which is the main protector of stainless steel. With the addition of carbon on the surface, stainless steel is resistant to O2. Additionally, the carbon element has the self-healing characteristic which makes it undamaged once it’s cut or broken.
- Resistant to hot temperature
Stainless steel, especially the austenitic one, is resistant to hot temperature. The resistance to high temperature is due to the high amount of chromium. The higher chromium is, the more resistant it is to elevated temperature.
- Resistant to low temperature
The austenitic stainless steel is not only resistant to hot temperature, but also is to the low temperature. In other words, the austenitic stainless steel has higher cryogenic resistance than at the ambient temperatures. Meanwhile, the other steels, such as ferritic, martensitic, and precipitation hardening steels are not cryogenic resistant since their toughness will drop significantly at low temperature.
- Magnetic and Non-magnetic
Stainless steel has types of grades which some of them are magnetic while the others aren’t. The response to magnetic and non-magnetic is depending on the content and with the help of cold working. However, cold working does not really work on some stainless steel grades, like nickel grades 310 and 316.
Types of Stainless Steel
Generally, stainless steel has five types or grades, such as:
- Austenitic Stainless Steel is stainless steel grade type 200 or 300 series. The main characteristics of austenitic stainless steel grades are highly resistant to corrosion (due to the higher chromium content), non-magnetic, has three subtypes (straight, L, and H), formable, and can only be hardened by cold working.
- Ferritic stainless steel is stainless steel grade type 400 series. Its main characteristics are low resistant to corrosion but highly resistant to corrosion cracking, magnetic, and hardened by cold working.
- Martensitic stainless steel is stainless steel grade type 400 and 500 series. Its main characteristics are magnetic, strong, resistant to heat, and has a medium resistant to corrosion. Martensitic stainless steel grades are often used as hardware, cutlery, machinery, screws, etc.
- Precipitation Hardening Grade is stainless steel grade type PH. Its main characteristics are highly resistant to corrosion (equal to austenitic grades), magnetic, solid, and high resistant to heat. PH grades are usually used as aerospace components.
- Duplex is a stainless steel grade with a mixture of austenitic and ferritic. Its characteristics are high corrosion resistance, high stress corrosion cracking resistance, and solid. Duplex stainless steel grades are often used in water treatment plants as well as heat exchanger elements.
Generally, there are five stainless steel grades, including Austenitic Stainless Steel, Ferritic Stainless Steel, Martensitic Stainless Steel, Precipitation Hardening Grade Stainless Steel, and Duplex Stainless Steel. Most of them are magnetic, except the Austenitic Stainless Steel Grade.