What metal materials include and what.

Metal materials include ferrous metals and non-ferrous metals.

According to colors and properties, metals are divided into ferrous metals and nonferrous metals. Ferrous metals mainly refer to iron, manganese, chromium and their alloys, such as steel, pig iron, ferroalloy and cast iron.

Ferrous metal materials are the general name of iron, chromium and manganese in industry. It also includes ferroalloys of these three metals, especially black steel and steel. Compared with ferrous metals, non-ferrous metals are actually silver-white in pure iron and chromium, and silver-gray in manganese.

Because the surface of steel is usually covered with a layer of black ferroferric oxide, manganese and chromium are mainly used to smelt black alloy steel. Therefore, it will be "wrongly classified" as a ferrous metal. Non-ferrous metals, also known as non-ferrous metals in a narrow sense, are the general names of all metals except iron, manganese and chromium.

Nonferrous metals can be divided into four categories:

1. Heavy metals: Generally, the density is above 4.5g/cm3, such as copper, lead and zinc.

2. Light metals: low density (0.53 ~ 4.5g/cm3) and active chemical properties, such as aluminum and magnesium.

3. Precious metals: the content in the earth's crust is small, difficult to extract, high in price, high in density and stable in chemical properties, such as gold, silver and platinum.

4. Rare metals: such as tungsten, molybdenum, germanium, lithium, lanthanum and uranium.