Technical Information on Stainless Steel

Columbus Stainless produces three classes of stainless steel, namely austenitic, duplex and ferritic.

Austenitics


The austenitics are comprised of three subclasses:

Cr-Ni-(Mn) austenitics - e.g. 304/1.4301, 321/1.4541, 202. Read more


The Cr-(Mn)-Ni austenitics are the most versatile and widely used of all the stainless steels. Their chemical composition, mechanical properties, weldability and corrosion/oxidation resistance provide the best all-round performance stainless steels at relatively low cost. They have excellent low temperature properties and respond well to hardening by cold working. The carefully controlled chemical composition of the Cr-(Mn)-Ni austenitics enables them to be deep drawn without intermediate annealing. This has made them dominant in the manufacture of drawn stainless steel parts such as sinks and saucepans. They are readily press-braked or roll formed into a variety of shapes for applications in the industrial, architectural and transportation fields.

Select an option below for more information:

Click here to download the full Cr-Ni-(Mn) austenitics technical brochure (PDF - 600kb)

Cr-Ni-Mo austenitics - e.g. 316L/1.4404, 316Ti/1.4571, 1.4436. Read more



The Cr-Ni-Mo austenitics are molybdenum bearing austenitic stainless steels having very good corrosion resistance in many aggressive environments.

The molybdenum addition ensures more resistance to pitting and crevice corrosion in chloride containing media, sea water and chemical environments such as sulphuric acid compounds, phosphoric and acetic acids.

The lower rate of general corrosion in mildly corrosive environments gives the steel good atmospheric corrosion resistance in polluted marine atmospheres. As they are austenitic, they have excellent ductility, formability and toughness even at sub-zero temperatures.

Click here to download the full Cr-Ni-Mo austenitics technical brochure (PDF - 600kb)

Heat resisting austenitics - e.g. 309S/1.4833, 310S/1.4845. Read more

The heat resisting austenitics are highly alloyed stainless steel used for their excellent oxidation resistance, high temperature strength and creep resistance in high temperature applications. They are tough and ductile and can be readily fabricated and machined.

U-309S-1.4833 has very good oxidation resistance and this is improved even further with U-309S Si- 1.4828, which has a higher silicon content.

Click here to download the full Heat Resisting austenitics technical brochure (PDF - 500kb)

Ferritics

The ferritics are comprised of three subclasses:

Utility ferritics - e.g. 3CR12, S41003/1.4003, 410S. Read more


3CR12 is recognised as the original and now the world’s most specified 12% chromium utility ferritic stainless steel.

The main advantage of these utility ferritics over other ferritic stainless steels is that they are tough, even when welded, in thicknesses of up to 30mm and retain their toughness at temperatures below freezing point.

The corrosion resistance of the utility ferritics is largely determined by their chromium content and is thus similar to other 12% chromium ferritic stainless steels.

Click here to download the full Utility Ferritics technical brochure (PDF - 630kb)

Standard ferritics - e.g. 409/1.4512, 430/1.4016, 439/1.4510. Read more


Standard ferritic stainless steels are plain chromium stainless steels, and can be stabilised with niobium and/or titanium. Annealed standard ferritics are ductile and can be formed using a wide variety of roll forming or mild stretch bending operations as well as the more common drawing and bending operations. They do not harden excessively during cold working.

Being ferritic, they are not susceptible to stress corrosion cracking. The steels have limited weldability and should not be used in the as-welded condition for dynamic or impact loaded structures.

Click here to download the full Standard Ferritics technical brochure (PDF - 460kb)

Moly ferritics - 434/1.4113, 436/1.4526, 444/1.4521. Read more


Moly ferritic stainless steels are chromium stainless steels alloyed with Molybdenum, and can be stabilised with niobium and/or titanium.

Annealed moly ferritics are ductile and can be formed using a large variety of roll forming or mild stretch bending operations as well as the more common drawing and bending operations. They do not harden excessively during cold working.

Being ferritic, they are not susceptible to stress corrosion cracking.

Click here to download the full Moly Ferritics technical brochure (PDF - 340kb)

Duplex

The duplexes are comprised of two subclasses:

Lean duplexes - e.g. 2001/1.4482, 2304/1.4362. Read more


The duplex stainless steels have a microstructure, when heat treated properly, of nearly equal proportions of austenite and ferrite. This microstructure ensures that the duplexes are much more resistant to stress corrosion cracking (SCC) than austenitic stainless steels.

The specification 0.2% Proof Stress of the duplexes is more than double that of austenitic stainless steels such as the U-304 types and U-316L types. This often allows down gauging in the design, depending on Young’s Modulus and buckling limitations.

Click here to download the full Duplex technical brochure (PDF - 470kb)

Standard duplexes - e.g. 2205/1.4462. Read more


The duplex stainless steels have a microstructure, when heat treated properly, of nearly equal proportions of austenite and ferrite. This microstructure ensures that the duplexes are much more resistant to stress corrosion cracking (SCC) than austenitic stainless steels.

The specification 0.2% Proof Stress of the duplexes is more than double that of austenitic stainless steels such as the U-304 types and U-316L types. This often allows down gauging in the design, depending on Young’s Modulus and buckling limitations.

Click here to download the full Duplex technical brochure (PDF - 470kb)

Other Technical Literature

Columbus also provide the following literature, that is available for download: