Surface chemistry of cooking
Stainless steel is considered stainless because it has at least 11% chromium by mass. Chromium is a relatively inert metal and does not rust or react as easily as plain carbon steel. This is what makes it an exceptional material for cooking. It is also fairly inexpensive, but does not have a very high thermal conductivity. From a surface standpoint, this is because of the thin layer of chromium oxide that is formed on the surface. This thin layer protects the metal from rusting or corroding. While it is protective, the oxide layer is not very conductive, which makes cooking food less efficient than it could be. For most cooking applications, high thermal conductivity is desirable to create an evenly heated surface on which to cook. In this way, stainless steel is usually not considered high-grade cookware.
Orthodontic archwire
In 1929, stainless steel was introduced for the use of making appliances. This was the first material that truly replaced the usage of noble alloys in Orthodontics. Steel wire alloys, in comparison to the noble metals, were relatively cheaper. They also had better formability and can be readily used to be soldered and welded for fabrication of complex orthodontic appliances. The stainless steel alloys are of "18-8" austenitic type which contain Chromium (17-25%) and Nickel (8-25%) and Carbon (1-2%). Chromium in this stainless steel alloy forms a thin oxide layer which blocks the diffusion of oxygen into the alloy and allow for the corrosion resistance of this alloy. Angle used stainless steel in his last year practicing orthodontics. He used it as a ligature wire in his patient's mouth. At that time, Emil Herbst was the main opponent of the Stainless steel based alloys. According to him, he preferred using Noble alloys over stainless steel. By 1950, 300 series stainless steel alloy was used by the majority of orthodontists in United States, as European Orthodontists believed in using functional appliances such as Activator appliance with patient's malocclusions.