Stainless steels families

A complete range

We offer a complete range of solutions with 5 categories of Stainless Steel differentiated by the alloying elements added to iron, carbon and chromium.

> Austenitics or 300 series 

 0.015 to 0.10% carbon, 16 to 21% chromium, 6 to 26% nickel, 0 to 7% molybdenum. The presence of nickel improves corrosion resistance and makes stainless steel more ductile. The presence of molybdenum further enhances the resistance to corrosion in an acid medium. The most  common grades are 304/304L et 316/316L. 

> Ferritics or 400 series: the KARA ferritic offer

0.02 to 0.06% carbon, 10.5 to 30% chromium, 0 to 4% molybdenum. These grades commonly used internally are now being developed for envelope and structural products. 

KARA is the Aperam brand for ferritic stianless steels.
Unlike other stainless steels, the KARA range doesn't contain nickel and is thus immune from the erratic price fluctuations of this alloying elements.
Prices are more stable over time: a strong argument in the construction sector where projects costing and economic design are key elements.  
 
> Austeno-ferritics or duplex

0.02% carbon, 0 to 4% molybdenum, 1 to 7% nickel and 21 to 26% chromium. They offer excellent qualities for a cost price that is contained because of their low nickel content, material that suffers from highly speculative prices.

> Martensitics

 0.1% carbon, 10.5 to 17% chromium. Mainly used for tooling, cutting tools and springs. 

> Austenitics with manganese or 200 series

 these are chromium manganese steels, with a low nickel content (always below 5%).

 

The stainless steels that are traditionally used for Building & Construction can be grouped into three major categories:

  

  Austenitic S300
 Ferritic S400
 Solutions KARA 
Duplex
       

 

Each of these families has specific mechanical properties:

hardness,  yield stress, breaking strength, elongation, etc. For example, austenitic and austenoferritic stainless steels have expansion coefficients higher than the other steels. Their thermal conductivity is less than ferritic stainless steel and traditional steels. The austenitics have a very high level of resilience – the ability of a material to resist brittle fracture – at any temperature. Due to their very high yield strengths, superior to other steels and better than other stainless steels families, Duplex are commonly used for structures, bridges and footbridges.

More information, consult our selection guide