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.
Safety razor
Until the 1960s, razor blades were made of carbon steel. These were extremely prone to rusting and forced users to change blades frequently. In 1965, the British company Wilkinson Sword began to sell blades made of stainless steel, which did not corrode nearly so quickly and could be used far longer. Wilkinson quickly captured U.S., British and European markets. As a result, American Safety Razor, Gillette and Schick were driven to produce stainless steel blades to compete. Today, almost all razor blades are stainless steel although carbon steel blades remain in limited production for lower income markets. Because Gillette held a patent on stainless blades but had not acted on it, the company was accused of exploiting customers by forcing them to buy the rust-prone blade.