Chrome plating

Chrome plating
Chromium is a kind of silver white metal with slight blue. Modern scientific research found that its relative atomic mass is 51.99, density is 6.98~7.21g/cm3, melting point is 1875~1920 ℃, standard electrode potential is Yush/c, -0.74V, old "/c," -0.41V and P very+/Cr shake -1.33V. Metal chromium is easy to passivate in the air, and a very thin passivation film is formed on the surface, which shows the properties of precious metals.
The chromium plating layer has high hardness, which can vary in a large range of 400-1200HV depending on the composition of the plating solution and process conditions. The chromium plating layer has good heat resistance. When heated below 500 ℃, there is no significant change in its gloss and hardness. When the temperature exceeds 500 ℃, it begins to oxidize and change color, and when the temperature exceeds 700 ℃, the hardness begins to decrease. The friction coefficient of the chromium plating layer is small, especially the dry friction coefficient, which is the lowest among all metals. So the chromium plating layer has good wear resistance.
The chromium plating layer has good chemical stability and does not work in alkali, sulfide, nitric acid and most organic acids, but can be dissolved in hydrochloric acid (such as hydrochloric acid) and hot sulfuric acid.
In the visible light range, the reflection ability of chromium is about 65%, which is between silver (88%) and nickel (55%). Due to its non discoloration, chromium can maintain its reflection ability for a long time and is superior to silver and nickel

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