Grades of Stainless Steel
Grades of Stainless Steel
Stainless steel grades are typically categorised based on their chemical composition, with different grades containing varying amounts of elements such as chromium, nickel, and molybdenum. Here are some of the common grades of stainless steel:
Source: The Southern Africa Stainless Steel Development Association (Sassda)
Austenitic stainless steel
This is the most commonly used type of stainless steel, accounting for more than 70% of stainless steel production. It contains high levels of chromium and nickel, is non-magnetic, highly corrosion-resistant, and has good formability and weldability.
Common grades of Austenitic stainless steel include 304, 316, and 321.
Ferritic stainless steel
Ferritic stainless steel contains high levels of chromium but lower levels of nickel. It is magnetic, highly corrosion-resistant, and has good formability and weldability. It is commonly used in automotive applications and household appliances.
Common grades of Ferritic stainless steel include 409 and 430.
Martensitic stainless steel
Martensitic stainless steel contains high levels of carbon and lower levels of chromium and nickel. It is magnetic, has good strength and hardness, and is commonly used in knife blades, turbine blades and dental instruments.
Common grades of Martensitic stainless steel include 410 and 420.
Duplex stainless steel
Duplex stainless steel contains a balanced mixture of austenitic and ferritic stainless steel, making it strong, corrosion-resistant and highly durable. It is commonly used in chemical and petrochemical industries, marine applications, and oil and gas pipelines.
Common grades of Duplex stainless steel include 2205 and 2507.
There are also many other specialised grades of stainless steel, each designed for specific applications, such as heat-resistant stainless steel, precipitation-hardening stainless steel, and super-austenitic stainless steel.
