What exactly is stainless steel? Stainless steel is a steel alloy with chromium in it. It has a minimum of eleven percent chromium. It is different from carbon steel because it has the chromium present it helps to stop the corrosion of the metal. With carbon steel it rusts quickly when it is exposed to the air or moisture. There are over one hundred and fifty. Out of the hundred and fifty only fifteen are more commonly used.
It is used in many things because it has a resistance to corrosion and staining. But also is low maintenance, relatively low cost, and has a familiar luster. It is used in sculpture, building facades and building structures.
It is also used in everyday items. For example the knifes that you use for your kitchen are made of stainless steel so that they last longer. If it were made out of carbon steel it would show signs of corrosion quickly. Also the band on your watch is made from stainless steel.
For each of the different types of metal there are different coatings. The reason for that is because it depends on how much exposure the metal is going to get. On carbon steel the rust is called iron oxide and when the rust is present it speeds up the process. It continues to spread thru the metal and to the metals internal structure. Making the steel unusable. Eventually if the metal is still exposed to the environment it will develop holes and crumble when you try to pick it up.
With stainless steel, which is also known as corrosion resistant steel, have high amounts of chromium in it so that it can protect the metal from its environment. The chromium oxide actually helps to stop the rust from spreading.
This type of corrosion protection was first recognized in 1812. His name was Pierre Berthier. He was a French metallurgist. He noticed the reaction of the metal when it was exposed to certain acids. He actually then suggested that it start to be used when making cutlery. Unfortunately at that time it was hard for them to make a metal that was low in carbon and high in chromium. And the metals that they were able to make that had high chromium were way to brittle to use.
It wasn't until 1912 that is was up to be patented. It was in the US by a man named Elwood Haynes. The patent was not approved until 1919.