How to identify trivalent chromium and hexavalent chromium in electroplating
Author: Robby
Electroplated trivalent chromium and hexavalent chromium can be identified by surface luster, color depth, corrosion resistance and environmental protection.
Surface luster and color shades: trivalent chromium galvanized surface luster is mostly semi-glossy or glossy, with the growth of the use of time, the surface luster will gradually become darker, but generally softer. The surface luster of hexavalent chromium zinc plating is mostly bright, vivid and eye-catching, but it is easy for the coating to fall off. The color of trivalent chromium zinc plating is mostly silver-white, showing silver-gray; although hexavalent chromium plating solution is also white or silver-white, the color is lighter and the silver is brighter.
Anti-corrosion performance: The anti-corrosion performance of trivalent chromium is more superior than that of hexavalent chromium. The corrosion resistance of trivalent chromium under the same conditions is 1.5 times of that of hexavalent chromium, so trivalent chromium has better anti-corrosion performance.
Environmental protection: Trivalent chromium plating process has lower pollution and toxicity compared with hexavalent chromium plating process. Trivalent chromium plating solution is less polluted, its toxicity is only 1% of hexavalent chromium, plating does not produce harmful chromic acid mist, and the concentration of plating solution is low, and sewage treatment is simple. While hexavalent chromium is not environmentally friendly, toxic, and is listed as a class of controlled pollutants by the state.
In summary, the difference between electroplated trivalent chromium and hexavalent chromium can be identified by observing the surface luster, color depth, anti-corrosion properties and considering environmental friendliness.