The name ferrous metal and non-ferrous metal
The name ferrous metal and non-ferrous metal often misu […]
The name ferrous metal and non-ferrous metal often misunderstands that black metal must be black, but it is not. There are only five types of ferrous metals: iron, manganese, chromium, vanadium, and titanium. And none of them are black. Pure iron is silvery white; chromium is silvery white; manganese is grayish white. Because the surface of the iron is often rusted, covered with a mixture of black ferroferric oxide and brown iron oxide, it looks black. So people call it "black metal." Often referred to as "black metallurgical industry", mainly refers to the steel industry. Because the most common alloy steels are manganese steel and chrome steel, manganese and chromium are also considered "black metals".
Except for iron, manganese, chromium, vanadium, and titanium, all other metals are considered non-ferrous metals.
Among non-ferrous metals, there are various classification methods. For example, according to the specific gravity, the specific gravity of aluminum, magnesium, lithium, sodium, potassium, etc. is less than 4.5, called "light metal", and the specific gravity of copper, zinc, nickel, mercury, tin, lead, etc. is greater than 4.5, called "heavy metal". Like gold, silver, platinum, rhodium, ruthenium, etc., it is called "precious metal". Radium, uranium, thorium, thorium, thorium and so on are radioactive, called "radioactive metal", and there are also like yttrium, yttrium, zirconium, yttrium and gold. , radium, radon, uranium, etc. because of the small content in the earth's crust, or relatively scattered, people call it "rare metal."