Types of Stainless Steel

The four types of stainless steel:

Martensitic
• Consist of carbon (0.2-1.0%), chromium (10.5-18%) and iron.
• Subject to specific heat treatments during production.
• Very hard and strong.
• They are ferromagnetic and possess poor formability.
• Use: turbine blades, cutlery and razor blades.

Ferritic
• Consist of chromium (most common 12.5% and 17%) and iron.
• Essentially nickel-free and contain very little carbon.
• Non-heat treatable.
• Ferromagnetic and possess adequate formability.
• Exhibit superior corrosion resistance to martensitic stainless steels.
• Use: vehicle exhaust systems, cooking utensils, washing machines and indoor architecture.

Austenitic• Consist of chromium (16-26%), nickel (6-12%) and iron.
• Other alloying elements (e.g. molybdenum) may be added or modified according to the desired properties
• Good formability and ductility (and makes them non-magnetic).
• Highly durable and corrosion resistant.
• Have high ductility, low yield stress, relatively high tensile strength and good weldability.
• Use: most common with wide range of uses.

Austenitic-Ferritic (Duplex)
• Consist of chromium (18-26%) nickel (4-7%), molybdenum (0-4%), copper and iron.
• Have a microstructure consisting of austenite and ferrite.
• High corrosion resistance with greater strength.
• Ferromagnetic and reasonable formability.
• Use: process industry and seawater applications.