In 1913, English metallurgist Harry Brearly was working on a project to develop new steels alloys to improve gun barrels when he accidentally discovered that adding chromium to low carbon steel gives it stain resistance. This amazing discovery leads to the birth of ‘Stainless Steel’ which is now one of the most common used materials in our modern progressive world.
The rise in the popularity of ‘Stainless Steel’ is due to its ability to resist corrosion. The chromium property in the steel react with oxygen in the atmosphere to form a thin, invisible layer of chromium (III) oxide, called the passive film. This layer is impervious to water and air and when the metal surface is scratched, more oxide will quickly form to recover the exposed surface (self-healing), hence protecting the material from corrosion.
Stainless steel also contains varying amounts of Carbon, Silicon and Manganese. Other elements such as Nickel and Molybdenum may be added to impart other useful properties such as enhanced formability and increased corrosion resistance.
Stainless Steel can be categorized into 5 classes: Austenitic, Ferritic, Martensitic, Duplex and Precipitation Hardened. The distinction between each class is based primarily on the predominant phase present in the stainless steel as determined by the major alloying elements.
The Birth of “Stainless Steel’ has certainly improve our standard of living, creating a stainless surrounding by using a wide range of stainless steel applications that are beneficial to our modern world.