Stainless Steel and YouPages : 1 - 23 - 4 - 5 - 6  


Stainless steel :

 Martensitic and precipitation hardening stainless steels
These steels generally contain 12 to 19% chromium, and their carbon content varies from 0.08 to 1.2%.
They may contain nickel and molybdenum as well as certain alloy additions such as copper, titanium or vanadium.
These steels combine good corrosion resistance with mechanical properties equivalent to those of top-of-the-range non-stainless steel alloys. These properties are obtained following the appropriate heat treatment: quenching and tempering for martensitic steels, quenching and ageing and/or thermomechanical treatment for precipitation hardening steels.
Ex :
- Martensitic steels: 1.4021 (or X20Cr13) ; 1.4034 (or X46Cr13) ; 1.4029 (or X29CrS13)
- Precipitation hardening steels : 1.4542 (or X5CrNiCuNb16-4) ; 1.4568 (or X7CrNiAl17-7)

 Ferritic stainless steels
These are Iron-Chromium or Iron-Chromium- Molybdenum alloys whose chromium content varies from 10.5 to 28% and whose carbon content does not exceed 0.08%.
These steels generally contain no nickel.
They are ferromagnetic, and contrary to popular belief, the fact that this steel family is ferromagnetic by no means implies poor corrosion resistance! Certain ferritic grades have corrosion-resistant properties that are comparable or even superior to those of the most common austenitic steels.
Ex : 1.4016 (or X6Cr17) - 1.4113 (or X6CrMo17- 1) - 1.4510 (or X3CrTi17)

 Austenitic stainless steels
These stainless steels are by far the most wellknown and widely used: in addition to a minimum chromium content of roughly 17%, they contain nickel (usually 7% and more) and possibly additions of molybdenum, titanium, niobium, etc.
Their tensile Mechanical properties are usually average, but for certain grades can be considerably improved through cold hardening.
On the other hand they are highly recommended for cryogenic applications, due to their lack of fragility at low temperatures.
Ex : 1.4307 (or X2CrNi18-9) - 1.4404 (or X2CrNiMo17-12-2)

 Austeno-ferritic stainless steels
These steels are characterised by high chromium contents (22% and more) and relatively low nickel contents (3.5 to 8%). A special feature of these steels is their dualphase structure (austenite + ferrite) at ambient temperature, and their austenite content ranges from 40 to 60% depending on the grade. They are also called "duplex" steels.
Their tensile Mechanical properties are higher than those of the austenitic steels (approximately 1.2 times for tensile strength and 2 times for yield strength). They can also be cold hardened.
Their corrosion resistance is generally higher than that of austenitic steels, especially in respect of generalised corrosion and stress corrosion.
Ex : 1.4462 (or X2CrNiMoN22-5-3)

 Heat-resisting stainless steels
Although all stainless steels can cover a certain range of high temperatures, depending on their composition, the term "refractory" is often used for highly alloyed grades suitable for working temperatures between 900 and 1150°C (Standard EN 10095).
Ex : 1.4841 (or X18 CrNiSi 25-21) - 1.4845 (or X8 CrNi 25-21)