corrosion of stainless steel - Damstahl

INTRODUCTION
Stainless steel is
ideal for critical
applications.
Stainless steel represents a large group of passive alloys, which, together,
contain a common main element, iron (Fe), and all of which contain at least
10.5% (Cr) and a maximum of 1.2% carbon (C). The role of Cr is to passivate.
Even though Cr is generally a less noble metal than iron, this passivation
converts the steel from being a 'normal', active alloy that fits within the
electrochemical series, to a passive alloy with a vastly improved corrosion
resistance.
And this passivity is exactly what makes stainless steel such an excellent
material! The combination of high corrosion resistance, reasonable prices,
an attractive appearance and a high degree of workability has made stainless
steel by far the most commonly used alloy within the full range of 'critical'
applications. Stainless steel is indeed a global 'hit', and it is most certainly
not a coincidence that it is extremely popular in dairies, slaughterhouses,
the pharmaceutical and chemical industries, households, refineries,
construction and design. In short, stainless steel is used anywhere one
might desire an attractive, polished look combined with a material that is
highly resistant to corrosion and easy to clean. Stainless steel may be the
closest one comes to a corrosion-resistant, universal alloy that can be used
for everything from mail boxes to skyscrapers.
Figure 0.1:
Atomium is a Brussels landmark which displays the iron atom's cubic,
space-centred structure (BCC). The sculpture is 105 metres high and
was originally made in aluminium for the 1958 World Expo. In 2005 the
coating was changed to acid-resistant 4404 (1.2 mm plates) supplied by
Aperam. Photo: Thomas Pauly, Euro-Inox [11].
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