【1】Differences in physical and chemical properties
Chromium (Cr) and nickel (Ni) are both transition metal elements and have many similarities in physical and chemical properties. For example, they both have a silvery-white metallic luster, good ductility and plasticity. However, there are still great differences in some properties, as follows:
1. Different density: The density of chromium is 7.19 g/cm3, while the density of nickel is 8.9 g/cm3.
2. Different melting points and boiling points: The melting point of chromium is 1907 degrees Celsius and the boiling point is 2672 degrees Celsius; while the melting point of nickel is 1453 degrees Celsius and the boiling point is 2732 degrees Celsius.
3. Different chemical properties: Chromium has high corrosion resistance and hardness, so it is often used in the manufacture of stainless steel, steel chrome parts, wheels and aircraft launchers. Nickel has good heat resistance and toughness, so it is often used in the manufacture of high-temperature alloy materials, casting molds, metal batteries, etc.
4. Different applications in stainless steel: Chromium is mainly used to form a chromium oxide layer that is not easily oxidized; nickel helps to improve the strength, ductility and corrosion resistance of the material.
5. Different magnetism: Chromium has stronger magnetism, and those that can be attracted by magnets usually contain more chromium.
6. Different appearance colors: Nickel-plated appearance is silvery white with a yellowish tint; chromium-plated appearance is bright white with a bluish tint.
[2] Different uses
The uses of chromium and nickel are also very different, mainly in the following aspects:
1. The main use of chromium: making stainless steel, steel chromium parts, wheels and aircraft launchers, etc.
2. The main use of nickel: making high-temperature alloy materials, casting molds, metal batteries, alloy materials in the power field, etc.
3. Different application scope: The application scope of chromium is mainly concentrated in metallurgy, chemical industry, machinery and aviation, while the application scope of nickel is wider, including medical, aviation, shipbuilding, chemical industry and power, etc.
In summary, although chromium and nickel have similarities in some physical and chemical properties, they have great differences in their uses and application scope. Different eras and different industrial fields require different types of metal elements. Chromium and nickel are both very important metal elements, and they play an important role in human production, life and technological progress.
