Stainless but Why?
In 1913, the British metallurgist Harry Brearly discovered that, while working on the project to improve the rifles’ pipes, they added low carbon chromium to the steel and gave it a stainless feature. The addition of carbon and chromium to iron has been the beginning of modern stainless steel.
In metallurgy; Stainless steel is described as an iron-carbon alloy containing a minimum of 12% chromium element. The chrome element is the basic component that protects the steel from corrosion. The fact that these steels are not stained like other steels is due to corrosion and non-corroding. Modern stainless steels may contain nickel, niobium, molybdenum and other elements such as titanium. Nickel, molybdenum, niobium and chromium increase the resistance to corrosion.
The addition of a minimum of 12% chrome to the steel adds to the strength of the stainless steel or provides corrosion resistance to other types. When combined with oxygen in combination with chromium steel, a thin layer in the atmosphere occurs. This invisible layer is a chromium mixed oxide layer. This is called passive film. The dimensions of these chromium atoms, their measurements, and their oxidation are similar to each other. They form a stable layer on the surface of the metal with only a few atomic masses. If the metal is cut or drawn, the passive film on the layer is affected and more oxide will soon form. It closes over the surface of the open air and is preserved from oxide corrosion. Passive filming requires oxygen for self-renewal, so stainless steel is less corrosive.