Chromium is a silvery-white metal with a slight bluish tinge. Metallic chromium passivates very easily in air, forming a very thin passivation film on the surface, thus displaying the properties of a precious metal.
Author: Anna
Chromium is a silvery-white metal with a slight bluish tinge. Metallic chromium passivates very easily in air, forming a very thin passivation film on the surface, thus displaying the properties of a precious metal.
The chromium plating layer has high hardness, which can be varied within a wide range of 400 to 1200 HV depending on the composition of the plating solution and process conditions. Chromium plating layer has good heat resistance, in 500 ℃ below the heating, its gloss, hardness are not obvious changes, the temperature is greater than 500 ℃ began to oxidize and discoloration, greater than 700 ℃ hardness began to decrease. The friction coefficient of chrome 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 act in alkalis, sulfides, nitric acid and most organic acids, but is soluble in hydrochloric acid (e.g. hydrochloric acid) and hot sulfuric acid. In the visible range, the reflective ability of chromium is about 65%, between silver (88%) and nickel (55%), and because the chromium does not change color, the use of its reflective ability can be maintained for a long time and better than silver and nickel.