Stainless Steel
Stainless Steel
Stainless steel has been around for more than a hundred years. It is an alloy made up of low-carbon steel with the addition of chromium. The properties that make steel stainless steel are owing to the presence of chromium in the alloy. The chromium content helps form a corrosion-resistant protective layer around steel that is self-healing when in contact with oxygen. This helps prevent corrosion and wear and tear on the metal. Further, these properties of stainless steel can be enhanced if other metals such as nickel, molybdenum, or nitrogen are added to the alloy.
Types of Stainless Steel
Depending on the quantities and types of different metals added to the alloy, there are several thousand types of steel. These types are roughly grouped into 60 grades, while these can further be grouped into three categories of stainless steel.
1. Austenitic stainless steel: One of the most commonly used types of steel, these have a high chromium content in their alloy base, making this type of steel more resistant to corrosion. This type of steel also does not display any magnetic properties, although the alloy might turn magnetic after cold work.
2. Ferritic stainless steel: These have a lesser nickel amount in the alloy. Further, even as the name denotes, this type of stainless steel is magnetic in nature. Although not as hard as austenitic stainless steel, ferritic stainless steel can be made stronger by coldworking. This is the second most commonly used type of stainless steel. It is also cheaper compared to other types.
3. Martensitic Stainless Steel: This is the least used type of stainless steel. One of the main reasons is probably its low corrosion resistance. However, they have high hardness, and hence, they are often used in places where high tensile strength and impact resistance are required. These types of alloys can balance their low corrosive power if a coating of protective polymer is done prior to their usage.
Why use Stainless Steel?
Stainless steel was accidentally discovered by an English metallurgist when he added chromium to low-carbon steel by mistake. He realized that this made the steel stain-resistant. Furthermore, elements may be added to steel alloys such as nickel, niobium, molybdenum, and chromium to increase its corrosion resistance. The chromium atoms, when in contact with oxygen, oxidize and form a thin protective layer around the steel surface. Since the size of the particles is almost similar, they stack neatly and create an even layer. This layer is also self-healing, even if a dent or damage is done to it. This process is called passivation, where a thin layer of oxide is formed over the surface of the stainless steel to protect it from water and air corrosion.
In iron, since the size of the iron atoms and the atoms of the oxide formed are different, the oxide is not stable enough to protect the iron from wear and tear or corrosion over time.
Benefits of Stainless Steel
1. In iron, since the size of the iron atoms and the atoms of the oxide formed are different in size, the oxide is not stable enough to protect the iron from wear and tear or corrosion over time.
2. Corrosion resistance: As also mentioned earlier, stainless steel is highly corrosion resistant due to its nickel and chromium content. While low-alloyed grades are able to resist atmospheric and water-based corrosion, high-alloyed grades are able to resist corrosion owing to alkaline, acidic, chlorine, and other such environments.
3. Appearance: The surface of stainless steel is easy to maintain while also providing a smooth and bright appearance.
4. Hygiene: Owing to its smoothness and ease of use, stainless steel is easy to clean and thus one of the most popular metals for use in kitchens and hospitals.
5. Easily Fabricated: Stainless steel is easily welded, bent, cut, molded, assembled, machined, and fabricated.
6. Impact resistance: Stainless steel showcases increased toughness at high temperatures, even below freezing points. Thus, it makes for an ideal metal for use in cryogenic applications.
7. Strength-to-weight advantage: Stainless steel is solid when cold working is employed. For this reason, reduced material thickness provides better strength.
8. Recyclable: Stainless steel, like other types of steel, is 100 percent recyclable. In fact, most steel produced worldwide is made from recycled steel or steel scrap.
9. Cost-effective: Since stainless steel is corrosion-resistant, it provides long-term value for the money. The life cycle of the end product is longer than that of products made from other metals.
We at MACA Casting and Machine develop all grades of stainless steel and provide you with comprehensive knowledge and technical support with respect to your requirements.