Chrome plating is a technique that consists of depositing chromium on a metal part by electrolysis to prevent its corrosion.
What is steel chrome for?
The steel in its natural state, rusts on contact with air in a short time, so we must protect it. One of the techniques is electrolytic chrome plating, although there are many more such as zinc plating or copper plating.
Due to its characteristic finish with a mirror effect, it is widely used in the automotive industry as decoration for visible parts, but also in parts that can wear out over time due to friction.
Chrome plating types
We can classify them into 2 types, according to their hardness and the finish we need.
Mainly we can differentiate 3 types of finishes, matte, satin and shiny. Each one is normally used for a type of part, for example, it is not normal to see a door knob with a shiny finish, it is usually used satin or even a matte finish.
With a few microns of thickness for the decoration of pieces. It is very durable over time, so it hardly needs maintenance treatments.
Hard chrome plating
It is used in the industry for all those parts that are going to suffer friction due to their high hardness, or very high temperatures. That is why it is perfect for the automotive industry since it extends the life of many of its components. It has the characteristic that it can correct the dimensions of a part that has suffered wear without having to manufacture a new one.
There are certain steel pretreatments that are not compatible with hard chrome, such as cemented or nitrided. That is why it is better that you consult the specialized company before carrying out any step since you can take a little surprise and have to do another different surface treatment.
Depending on the hardness we need, we will use one form or another. Even depending on the shape of the piece, we may need another treatment such as nickel plating.
As chrome plating alone has little anticorrosive power, we must first apply a copper or nickel plating to help protect the metal.
This is when the parts connected to the negative pole (anode), and lead connected to the positive pole (cathode), are immersed in a solution of chromic acid with sulfuric acid. This causes the lead particles to stick to the metal to be treated. This process is not like the others we are talking about here since it is normally the cathode that provides the material to coat the metal.
Once finished, they are washed to remove impurities and chemical residues so that when handling them they do not affect our skin.