Stainless steel refers to a group of iron-based alloys that are resistant to corrosion and heat. However, one of the most distinguishing features of stainless steel is its minimal chromium content of 10.5%, which confers improved corrosion resistance over other steels.
Stainless steel, like other steels, is largely made up of iron and carbon, but it also contains several other alloying elements, the most important of which is chromium. Stainless steel alloys with nickel, magnesium, molybdenum, and nitrogen are also common.
Stainless steel has a variety of corrosion qualities, including non-corrosive, rust-resistant steel, and simply stainless steel. Stainless steel is nearly three times the weight of aluminum.
Properties of stainless steel
Stainless steel has several attractive qualities that lead to its extensive use in the manufacturing of parts and components in a variety of industries. Most of all, because of its high chromium content, it is extremely corrosion resistant.
Steel that contains at least 10.5 percent chromium is 200 times more highly resistant to corrosion than steel that does not. Consumers will like its high strength and durability.
As well as its high and low-temperature resistance, better formability and ease of fabrication, minimal maintenance, highly durable, appealing look, environmental friendliness and recyclable nature. Stainless steel does not need to require much treatment, coating, or painting once it is in operation.
- Corrosion protection
- Exceptional tensile strength
- Very long-lasting
- Withstands extreme temperatures
- Formability and fabrication are simple.
- Low-cost to maintain (long-lasting)
- Appearance appealing
- Friendly to the environment (recyclable)
Stainless steel grading methods
Based on its structure, physical properties, and uses, stainless steel is classified using a number of numerical grading methods. There is allocation of a numerical grade for each type of stainless steel after they divide by its series number.
200, 300, 400, 600, and 2000 are the most prominent series numbers. The most prevalent grades are austenitic chromium-nickel alloys of types 304 and 316. The 400 Series, which comprises ferritic and martensitic chromium alloys, contains cutlery-grade stainless steel. Surgical steel is type 420, and razor blade steel is type 440.
Classifications for Stainless Steel
Stainless steels can divide into four types based on their crystal structure.
Ferritic
The stainless steel sheets of the 400 Grade are ferritic steels with a high chromium content ranging from 10.5% to 27%. They’re also magnetic, with good ductility, tensile-property stability, corrosion, temperature fatigue, and stress-corrosion cracking resistance.
Applications of ferritic stainless steel
Ferritic stainless steel is used in a variety of applications, including automotive components and parts, the petrochemical industry, heat pumps, furnaces, and consumer durables such as refrigerators and food equipment.
Austenitic
The most common variety of stainless steel is austenitic, which is high in chromium and contains varying amounts of nickel, manganese, nitrogen, and carbon. The subclasses of austenitic steels are the 300 series and 200 series, which are defined by the alloys utilized.
The inclusion of nickel distinguishes the austenitic composition of the 300 series. Manganese and nitrogen are commonly used in the 200 series. 304 is the most common stainless steel grade.
Applications of austenitic stainless steel
It is common in kitchen appliances, cutlery, food processing facilities, and structural components in the automotive and aerospace industries, and is sometimes known as 18/8 since it contains 18% chromium and 8% nickel. Another prevalent stainless steel is 316.
It’s used to make food preparation equipment, laboratory benches, medicinal and surgical equipment, yacht fittings, pharmacological, textile, and chemical processing equipment, among other things.
Martensitic
Stainless steels in the 400 Grade range include martensitic stainless steels. Moreover, they range in carbon content from low to high, with 12 percent to 15% chromium and up to 1% molybdenum.
It’s useful when corrosion and/or oxidation resistance, as well as high strength at low temperatures or creep resistance at high temperatures, are necessary. Magnetic martensitic steels have a high level of strength and ductility, making them easier to deal with.
Applications of martensitic stainless steel
Compressor blades and generator parts, kitchen utensils, fixtures, nuts and screws, pump and nozzle parts, surgical and dental instruments, electric motors, pumps, control valve, machine parts, sharp surgical instruments, cutlery, cutting blades, and other cutting hand tools are all examples of applications for martensitic stainless steels.
Duplex
Duplex stainless steels have a combination of the microstructure of ferrite and austenite, as the name suggests. The chromium and molybdenum content is significant, with 22 % to 25 % chromium and up to 5% molybdenum, accordingly, and a very low nickel percentage.
According to its duplex structure, stainless steel possesses a number of desirable characteristics. To begin with, it is twice as strong as traditional austenitic or ferritic stainless steels, with higher corrosion resistance and toughness.
Applications for duplex stainless steel
Duplex stainless steel is used in chemical, oil, and gas processing and equipment, marine, high chloride environments, pulp, and paper industry, cargo tanks for ships and trucks, bio-fuels plants, fluoride containment or compressed gases, transportation, heat exchanger tubes, construction, the food industry, desalination plants, and components for FGD systems.
Other applications
Transportation and automobiles
It plays an important part to make several vehicle parts, including exhaust systems, screens, and trims. Therefore, manufacturers are favoring stainless steel for structural components as technology advances.
Technology in the medical field
Stainless steel is sound in sterile and clean surroundings because it is easy to clean and does not corrode easily.
Building trade
Stainless steel application has become a crucial aspect of the building profession due to its strength, resilience, and flexibility.
Conclusion
To conclude, stainless steel demand is growing at a pace of roughly 5% per year around the world. Annual consumption has surpassed 20 million tons, and it is increasing in sectors such as construction and household appliances.
Stainless steel’s appealing look, corrosion resistance, low maintenance, and strength continue to find new applications. Stainless steel is more expensive than normal steel grades, but it has better corrosion resistance, requires less maintenance, and doesn’t require painting or other protective coatings.
When you consider service life and life-cycle expenses, stainless steel becomes more economically viable. For instance, stainless steel spring manufacturers and suppliers are in great demand due to the endless properties of stainless steel and its benefits.
