Stainless steel is not a single material but a vast family of alloys designed to withstand aggressive environments. In architecture, its history begins in the 1930s with the Chrysler Building in New York.
Unlike ordinary steels, which oxidise to form rust (porous and destructive), stainless steel contains chromium that reacts with oxygen to form a very thin layer of oxides and hydroxides. This passive film is impermeable and blocks the diffusion of oxygen towards the underlying metal. If scratched, the film regenerates instantly, provided the environment is not devoid of oxygen.
The grade AISI 304 (1.4301) is the standard for interiors and exteriors in rural or non-saturated urban atmospheres. However, in coastal areas or where de-icing salts are present, the use of AISI 316 (1.4401) becomes necessary; it contains molybdenum (2-3%), an element that dramatically increases resistance to pitting corrosion caused by chlorides.
Standards
European and international references applicable.
Physical properties
Usage environment
From 2B (cold-rolled) to BA (mirror-polished), through satin, brushed or mechanically decorated finishes. In coastal or saline areas AISI 316 is mandatory.