Steel in moist air or water will form reddish-brown rust on its surface, which is commonly known as rust. If chromium is added to the steel to turn it into chromium steel, the steel will not rust. Because, in the periodic table of the elements, the arrangement of iron and chromium are very close. They have a similar electronic layer structure and the same lattice type, and their atoms can be replaced at any position in the lattice.
It is the structural change that leads to the change in the properties of steel. Specifically, after ordinary steel interacts with water, the iron element in it will form hydrated iron oxide with water, that is, reddish brown rust. But after adding chromium, because chromium can replace iron in steel, it will not produce rust of hydrated iron oxide, so it will become corrosion-resistant stainless steel.
Chromium stainless steel can be manufactured by adding chromium to steel. Similarly, if nickel, manganese, titanium, copper, molybdenum, aluminum, silicon and some rare earth elements are added in a little further away, different types of stainless steel can also be manufactured, which creates favorable conditions for the development of a variety of stainless steels and the expansion of their application range.
