Steel is an alloy of iron and other elements, including carbon. The following elements are always present in steel: carbon, manganese, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen and aluminum.
Stainless steels and surgical stainless steels contain a minimum of 11% chromium, often combined with nickel, to resist corrosion (rust). Some stainless steels, such as the ferritic stainless steels are magnetic, while others, such as the austenitic, are nonmagnetic. Corrosion-resistant steels are abbreviated as CRES.
process – “coating”
Chromium (Cr) (BBC podcast 34:00) – Chromium is the metal of modernity – the key ingredient in stainless steel. But this chemical element also has a dark side – one brought to public attention by Erin Brockovich.
- Chrysler Building – Completed in 1930, New York City, standing 1,046 feet (319 m) high on the east side of Manhattan. Originally built for the Chrysler Corporation. November, 1929, the Chrysler Building not only the world’s tallest building, but also the world’s tallest structure. The Chrysler Building is an example of Art Deco architecture, and the distinctive ornamentation of the tower is based on the hubcaps that were then being used on Chrysler automobiles. The dome and spire are covered in stainless steel – not as single sheet of the stainless steel has been replaced since they were installed in 1930. Detail of the ornamentation on the upper tower of the Chrysler Building, New York City.
Challenges for you to work on…
- find interesting and unusual uses of stainless steel. Why is stainless steel a good choice for this? What happens if some other material is used?