Internal Structure

Primary Alloying Elements




Cr, Ni , Mo 


Cr, C veya Ni 


Cr, Ni , Mo 


Austenitic-Ferritic (Duplex) :

This kind of stainless steels which are called as duplex in industry, include 18-28% Cr and 4.5 Ni in general. Nickel content is insufficent for making structure fully austenitic that’s why they contain also ferritic structure. This combined structure provides both strength and ductility.

Duplex steels are mainly used in petrochemicals, paper and ship building industry.


Martensitic :

Martensitic stainless steels contain 0.1% carbon and chromium. They have average corrosion resistance. The hardness of martensitic steels can be increased if heat treatment applied.

Turbine blades, knives and surgical operation instruments are the major use areas of martensitic steels.

The most important alloying elements in the structure of stainless steels are chromium-nickel-moybdenum and manganese in order of importance. Nickel and chromium specify structure of stainless steel if it is ferritic or austenitic.

 Austenitic :

Austenitic stainless steels are the most commonly used group in industry. This group includes 304, 316 qualities and also high alloy steels such as 310S.

Min.%/7 Ni content is enough to make internal structure austenitic in stainless steels. Nickel improves ductility properties, heat resistance and welding properties to stainless steel.

Housewares, containers, industrial piping and vessels, architectural facades and building structures are some of the austenitic stainless steel industrial applications.


Ferritic :

Ferritic stainless steels include 12-18% Cr and 0.025-0.08% C.430 Quality is the most commonly used ferritic steel in industry. The structure of ferritic stainless steels are similar with steels but their corrosion resistance is extremely high.

The major use areas of ferritic steels are kitchen utensils, washing machines, indoor decorative applications, automobile chassis parts, exhaust components, hot water tanks.