By: Martina Celegato
Submitted: 2009-07-13 08:30:41 | Word Count: 494
Stainless steel is an alloy based on iron, which combines together the mechanical properties of steels and some specific features of corrosion resistance. These alloys are also liable to tarnish.
This means that they have the possibility to passivate, that means to get covered with an invisible layer of oxides that protects the underlying metal from corrosive attacks. Stainless steel is the name given to a type of steel with high chromium contents that thanks to this feature does not rust when exposed to water and air. They are a very important class of steels, used in countless applications. In fact, nowadays both stainless steel furniture and construction machinery are very popular.
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The discovery of this type of steel is due to Harry Brearly, who while was experimenting with various types of alloys for the reeds of guns, noticed that a type of steel with a certain percentage of chromium did not get rusted when exposed to the atmosphere. Later this property was explained by the passivation of chromium, which forms a very thin oxide film on the surface, continuous and stable. The following progresses in metallurgy between the forty and the sixty have extended their development and their applications. They are still refined and adapted to the demands of various industries such as oil/petrochemical, mining, energy, nuclear and food industries.
Over the years, new productive technologies have been developed that, using the processes of stainless steel welding to weld steel pipes, make possible to market a product of the highest quality. It is thanks to the technology of high-frequency welding that in the stainless steel pipe, the heat affected zone and known as the most sensitive to corrosion, has been reduced by section and then, for the same alloy, it provides a lower propensity to oxidation on the surface.
Stainless steel is still refined and adapted to the demands of various industries like petroleum, petrochemical, mining, energy, nuclear, food and obviously building. A lot of machines are built with parts made of steel, from pipes to sheet to steel trolleys.
For over 70 years stainless steel is used for external cladding of buildings.
Thanks to the advances in processing and finishing technologies of stainless steel, the architects now have a wide range of high quality and high resistance stainless steel. This is also thanks to the characteristics of steel, a highly ductile, flexible and easily adaptable material. And that can be recycled and reused an infinite number of times, making it an important material for the future and for a sustainable economy.
While abroad, the use of stainless steel in cladding facades of the buildings is quite common, in Italy the use of stainless steel is more limited.
