Stainless Steel: Grades, Properties, and Applications

The beginning of stainless steel came in as a lucky accident. In 1913, in Sheffield, England, Harry Brearley was experimenting to create newer steel alloys for making stronger and better cannon barrels. During his work, some of the samples were resistant to rust and corrosion. Thus, making stainless steel known to the world. They were first used to make cutlery, which popularized Sheffield across the world. As more and more alloys were being created, stainless steel began to be used for various purposes like manufacturing equipment, tools, machinery, and even construction.

Now, Stainless steel is being used almost everywhere. Being a 100% recyclable product with such durability, its demand is booming at a rate of 5 percent every year. Last year, India itself produced over 3.13 million tonnes of stainless steel. This demand makes businesses find new and quicker ways to get their raw materials. Many such companies are now opting for steel online procurement. It helps get their quotation faster, better, and more efficiently. But before getting your procurement done, you can always double-check the details of your requirements. For that, we have gathered all the information about stainless steel you will need to be sure about your purchases.

Classification And Grades Of Stainless Steel

Stainless steel classifies a family of over 200 steel alloys that are predominantly made up of the elements iron and chromium. These are known to be highly resistant to corrosion and heat. It is because these alloys contain a minimum 10.5% of chromium. Depending on the needs of the final product, manufacturers alloy these steel into different grades with other elements such as nickel, carbon, silicon, manganese, and molybdenum, to improve its formability, heat resistance, and durability.

Austenitic Stainless Steel

Austenitic steel is the most prevalent type of stainless steel. Its fundamental microstructure is made of austenite, which is an alloy of iron and carbon that forms when the temperature rises above 723°C. This type holds high levels of chromium and is also mixed with nickel, manganese, nitrogen, and carbon. This stainless steel family is known for its hardness and tolerance to high temperatures.

Austenitic steels are further divided into the 300 series and 200 series based on the alloys being utilized. The 300 series of austenitic stainless steel mainly consists of at least 16% chromium and 6% nickel. Grade 304 is the most commonly known type of stainless steel. The 200 series involves manganese-containing austenitic steel alloys. The nickel percentage of these grades of steel is lower than 5%.

Ferritic stainless steel

In ferritic steels, mostly chromium is the only alloying element. Its concentration varies between 10.5 and 18%. The corrosion resistance of this type is quite moderate, and the manufacturing properties are low. However, they have certain characteristics such as being magnetic, good ductility, tensile-property stability, thermal fatigue, and stress-corrosion cracking resistance. This makes them more suitable for engineering purposes than austenitic grades. Ferritic stainless steel comes in the 400 series with grades such as 430, 434, 444, and many more.

Martensitic Stainless Steel

Martensitic stainless steel ranges in carbon content from low to high and holds 12 to 15% chromium and up to  1% molybdenum. Similar to ferritic grades, it has magnetic properties. Martensitic stainless steel will have inferior corrosion resistance compared to austenitic and ferritic grades of stainless steel. Furthermore, it also has lower weldability than other grades. However, the hardening abilities of this grade are better and can be heated to improve its qualities. They also belong to the 400 series with grades such as 410, 416, 440, and more.

Duplex Stainless Steel

Duplex stainless steel is made up of a mix of austenitic and ferritic stainless steel. As a result, it possesses the properties of both of its constituents. The compositions it contains are 23% chromium, 4% nickel, or  22% chromium, 5% nickel. Duplex stainless steels have unique properties such as high tensile strength, weldability, good stress corrosion resistance. Their durability ranges between ferritic grades and austenitic grades. Some of them are 2207 and 2507.

Properties Of Stainless Steel

Heat Resistant

Most stainless steel types have heat resistance. They work comparatively better than other steels at high temperatures. As they get a higher strength retention factor at increased temperatures, these alloys show resistance to heat. Especially, the alloys that contain high chromium resist scaling at high temperatures.

Ductility of Stainless Steel

Ductility is measured by the percent of elongation occurring during a tensile test. For austenitic stainless steel, the percentage is quite high. Thus, they can be formed using drastic methods like deep drawing.

Work Hardening Ability

A metal can strengthen through cold working processes. With the help of such working processes, stainless steel can increase its strength to a great extent. Thus, making the same grade of stainless steel useful for different purposes.

Stainless Steels Are Magnetic

Many stainless steel grades have magnetic responses. It refers to the attraction of steel to a magnet. Generally, austenitic grades are the only ones with no magnetic response. However, low austenitic grades can be stimulated to the magnet by cold working. On the contrary, grades like 316 and 310 cannot be stimulated even with cold working.

Applications Of Stainless Steel

Stainless steel is used in almost every industry. Distinctive properties like resistance to corrosion, heat resistance, work hardening, make stainless steel a very useful raw material for all types of business for various purposes.

1.    Architecture and Construction

● Buildings

● Bridges

● Airports

● Railway Stations

● Monuments

● Sculptures

2.    Medical Tools and Equipment

● Surgery Tools and Equipment

● Dental tools

● MRI Scanners

● Operating Tables and more

3.    Food and Catering

● Kitchen sinks

● Cutlery

● Heavy Duty Utensils

● Kitchen appliances

● Interiors Finishes

● Preserved Food Packaging

4.    Transportation

● Automobiles

● Rail cars

● Aircraft

● Ship Containers

● Road Tankers and more

5.    Heavy Duty Storage

● Chemical Barrels

● Valves and Pipes

● Oil rigs and more

● Machinery

● Industrial Tools and Equipment

Now that you know all about stainless steel. You are ready to go for your steel online procurement. OfBusiness is one of the leading procurement service agencies online. We procure all types and grades of stainless steel based on your demands. Get your quotations faster, better, and more efficient.

Go get your steel online procurement now!