Stainless Steel Types and Properties

Stainless steel is an alloy of steel with a minimum of 11% chromium and more than 50% iron content in it. It is corrosion resistant, as well as highly stain and rust resistant and requires minimum maintenance. Some of these properties can be altered by adding metals like molybdenum, titanium, nickel, etc. in the content of stainless steel that gives rise to changes in its mechanical and physical properties. Due to their changes there are hundreds of stainless steel grades which can be produced and used for various purposes. With this basic information about stainless steel types and properties, let's take a look at the stainless steel types and properties from the paragraphs mentioned below.

Types and Properties of Stainless Steel

As mentioned above, there are hundreds of grades depending upon their standards that are formed due to the addition of various metals in the stainless steel. But all these grades are summed up together into four main groups or families depending on the chemical and physical properties of stainless steel. These four types of stainless steel are very important with respect to their components as they are used in large-scale industries all over the world. In the coming up paragraphs, we will be reading more about these stainless steel types and properties, so take a close look.

Ferritic Stainless Steel
This type of stainless steel lacks other alloying elements and is known as plain chromium steel. The chromium content in this type is about 18% with a very low carbon content.

Properties

• Corrosion resistance is moderate
• Magnetic in nature
• No stress corrosion
• Used in annealed condition
• No hardening with heat
• Weldability is poor

Martensitic Stainless Steel
The martensitic stainless steel is defined as the one which is also plain chromium like the ferritic steel. It was the first to be developed for commercial usage and has a composition of 12 to 18% chromium because of its adaptable physical properties of steel. It has a high carbon content and is widely used in engineering applications.

Properties

• Corrosion resistance is moderate
• Magnetic in nature
• Treated with heat
• Poor weldability
• Hardest and most resistant to abrasion

Austenitic Stainless Steel
There is an addition of the metal nickel in this stainless steel type. This addition changes its microstructure giving rise to varied stainless steel properties, thus making it the most used (70%) stainless steel commercially. The composition is 18% chromium and 8 % nickel.

Properties

• Corrosion resistance is excellent
• Non-magnetic in annealed form
• No hardening with heat
• Ductile
• Hygienic and clean
• Good performance at any temperature
• Good weldability

Duplex Stainless Steel
Another very important family in the stainless steel types is the duplex, where the alloy contains both austenitic and ferritic microstructures. Because it is stainless steel, the basic chromium is quite high, 18 to 28% and nickel is moderate with 5 to 8% composition. Another addition to this microstructure is 2.5 to 4% of molybdenum which gives it the duplex property derived from both metals found in the composition of this type of stainless steel.

Properties

• Corrosion resistance is excellent
• No stress corrosion
• Excellent weldability
• Tensile and higher strength yield
• Easy to mold and extend

With this information about stainless steel types and properties, we have the basic knowledge about how stainless steel gets its unique and useful nature. Stainless steel is used for various purposes and is a popular material for kitchen appliances in almost every household, thus being a truly useful gift to mankind.