Chrome plating is the process of applying a layer of chromium onto a material, most commonly metal. Although it’s sometimes used for the purpose of decoration, chrome plating can be used for a number of purposes, including the protection of material layers. It’s a fantastic combatant of metal corrosion too.
The process of chrome plating includes five (somewhat basic) stages. First of all, a high amount of attention is paid to the object that is going to receive chrome plating. This could be a number of things, so it isn’t really particular what this might be. A number of chemicals are used in order to completely degrease the metals, ensuring that the surface is completely free of any components that may cause the chrome plating process to fail.
For the next major stage of the chrome plating process, the treated metal with undergo a number of further treatments in order to smooth the surface. Ensuring that the metal surface is as smooth as can be, the chrome plating outcome will result in a much higher degree of integrity over a longer time period. After being completely sure that the surface is smooth, the metal is carefully placed into a vat filled with treatment solution, which allows the metal to be gradually warmed up to the perfect temperature in order to apply optimal chrome plating.
In the final stage of the chrome plating process, the actual plating can begin. A vat is filled with chrome (chromium) components, allowing the compounds to find their way into the metal surface. The amount of time in which the metal remains inside the vat will always depend on the degree of thickness that’s desired for chrome plating.
Chrome plating is a fantastic technology, as it allows metal items to deal with exposure for a number of years. The metal bumpers on the front of vehicles is a fantastic example of chrome plating that holds itself up for decades, only needing general maintenance to keep in top condition.
There are a number of corrosion protection methods, but what exactly are they?
Active corrosion protection
The end goal of active corrosion protection is mostly to influence the reactions which often happens during corrosion, with the result being able to control not only the package contents, but also the reaction itself. This is done in such a manner that corrosion is avoided. Examples of this can be found in the development of corrosion-resistant alloys, along with inhibitors.
Passive corrosion protection
In passive corrosion protection, damage is ultimately prevented by isolating the contents from the aggressive corrosive agents by using various protective layers or films. However, though this is a form of protection, using this type of corrosion protection will not change the ability of the packaging contents corrosion chances, nor will it change the aggressive levels of the corrosive agent. This approach is known as ‘passive corrosion’ protection.
Permanent corrosion protection
The purpose of permanent corrosion protection is to provide any protection at the place of use. The stresses presented by biotic, climatic and chemical factors are often slight in this situation. Machines are located in factory sheds and are therefore protected from the extreme variations in temperature that can happen, which is the common cause of condensation.
Temporary corrosion protection
The stresses that can occur during transport and storage are often greater than those that occur at the place of use. Stresses can be manifested, for example, from extreme variations in temperature, which often result in a risk of condensation.
Have you ever wondered what’s the difference between decorative chrome or hard chrome plating?
Chromium is about the same hardness in both decorative chrome and hard chrome plating, about 800 to 1000 VHN (which is incredibly heavy). The main difference is found in the thickness of the deposit.
For the decorative purpose of chrome, it is seated best on nickel, which adheres incredibly well to copper – the combination of all three offers possibly the best corrosion protection resistance available. Decorative chrome thickness can vary from anywhere between a few hundredths of a mil to one mil. The mirror finish will effectively only be as good as the finish that is on the surface before the chrome, so it’s all a very difficult process at times.
For the purpose of being functional, or take either take advantage of the extremely low friction that chrome holds or for building surfaces and pistons, hard chrome will be plated with a thickness anywhere between 1 to 50 mills.
When used as a bearing surface, chrome simply must be micro-finished, something which will then provide a level of friction much lower than any other metal when used against the likes of steel, iron, brass, bronze or aluminium alloys. There’s something that you mustn’t do; Do not use chrome against chrome. Chrome is much harder than casehardened steel, so we are then left with a perfect set-up for longwearing working surfaces. Chrome will resist pretty much all organic and inorganic compounds and acids, except hydrochloric acid.