- Mar 19, 2018 -
Chromium is a slightly bluish, silver-white metal that is easily passivated in the air and forms a very thin passivation film on the surface, showing the properties of the precious metal.
The chrome plated layer has a high hardness, and its hardness can vary within a wide range of 400 to 1200 HV depending on the composition of the plating solution and the process conditions. The chrome plated layer has good heat resistance. After heating at 500° C. or less, its gloss and hardness have no obvious change. When the temperature is greater than 500° C., the oxidized discoloration begins, and the hardness greater than 700° C. begins to decrease. The chrome plated layer has a low coefficient of friction, especially a dry friction coefficient, and is the lowest among all metals. So the chrome layer has good wear resistance.
The chrome plated layer has good chemical stability and does not work in alkalis, sulfides, nitric acid, and most organic acids, but it can dissolve in hydrochloric acid (such as hydrochloric acid) and hot sulfuric acid. In the visible light range, chromium has a reflectance of about 65%, between silver (88%) and nickel (55%), and because chromium does not change color, it can maintain its reflective ability over time and superior to silver and nickel. .