Types of Stainless Steel

steel corrosion

Stainless steel is a type of steel alloy containing at least 10.5% chromium content by mass and a maximum of 1.2% carbon by mass. Stainless steel is most notable for its corrosion resistance, and this increases with raised chromium content. Additions of molybdenum can also enhance corrosion resistance.

Stainless steel is commonly seen around in the form of tubing, wire, bars, plates, and sheets used in tankers and storage tanks for chemicals and food products, industrial equipment, construction materials, major appliances, surgical instruments, cutlery, cookware, and much more.

But what people know as stainless steel is divided into the following types:


This type is based on Chromium with small amounts of carbon around 0.10% or less. They also have a similar microstructure to carbon and low alloy steels. They are limited in use to relatively thin sections due to lack of toughness when welded. Even if welding is not required, they offer a wide variety of applications. They cannot be hardened by heat treatment.


The most common type of stainless steel. Its microstructure is derived from the addition of Nickel, Manganese and Nitrogen, giving Austenitic their unique combination of weldability and flexibility. It cannot be hardened using heat treatment but has useful property so it can be work hardened to high strength levels while retaining the right level of ductility and durability. Standard austenitic steel is vulnerable to stress steel corrosion cracking.


This stainless steel is similar to ferritic in being based on Chromium but with higher Carbon levels up to 1%, allowing the metal to be heat tempered and hardened, similar to low alloy steel and carbon. They are required for high strength and moderate corrosion resistance.


This steel has a microstructure that is approximately 50% ferritic and 50% austenitic. This gives it higher strength than either ferritic or austenitic steels. They are resistant to stress corrosion cracking. It has comparable corrosion resistance to standard austenitic steels but with enhanced strength and resistance to stress corrosion cracking.

Precipitation hardening (PH)

This steel can develop very high strength by adding elements such as Copper, Niobium and Aluminium. They can be machined to complex and intricate shapes before the final aging treatment as there is minimal distortion from the final treatment.

No matter what type of stainless steel is used and how corrosion resistant, steel corrosion will eventually rear its ugly head. To stem this tide, a special polyvinyl chloride copolymer solution coating can be externally applied to give added rust protection. Specially formulated for stainless steel, Unituff OGS is easily applied and is non-seepage and non-rust creep.

To get the most information about Unituff OGS, formerly known as Seal n Peel, visit the Unituff website, https://unituffglobal.com/, or give them a call or message.