Stainless steel is one of the most non corrosive products on the market today. However, it’s not perfect and it is subject to corrosion. Thankfully, a process known as stainless steel passivation helps to protect the metal and make it far more resistant to corrosion.
What is Passivation?
To passivate something means to make it passive. However, it is not the same as a person or animal which is timid. When one speaks of passive metal, it means it’s unreactive to oxygen in the air, and oxygen is what causes steel to rust or oxidize.
Stainless steel is naturally passive and resistant to the effects of oxygen and moisture. This is caused by the addition of chromium to the alloy metal. However, during the manufacturing process, tiny bits of iron can be left behind on the surface of the metal. If left untreated, these tiny iron bits will eventually attract moisture and oxygen and begin to rust. This can cause pitting or even corrosion to develop in time, and will affect the natural passive layer of the metal.
To remove the free iron on the metal surface, nitric acid is often utilized. However, some processes use citric acid. This is the most effective method, as manual removal could result in damage to the material.
The Process
It is vital to know which alloys are in the metal before the stainless steel passivation process can begin. This will determine the type of chemical cleaner to use. The metal is then placed in a special chemical bath to remove foreign materials, oils, and other compounds which may be present. Plus, the steel goes through a de-scaling process.
The amount of time the materials are submersed is vital to the entire process. Temperature is also very important. If these factors are not monitored closely, problems like discoloration may develop.
Reasons to Passivate
There are many possible reasons to passivate your stainless steel. For example:
* When repairs have been made
* Caustic environments
* Installation of new equipment
* Discoloration or darkening of surfaces
Unless your stainless steel parts have undergone proper passivation, they will not truly be stainless and resistant to corrosion for many years. The process of passivating metals is an exact science and the slightest miscalculations can end up in disaster. It is very important to choose a professional service which understands the entire stainless steel passivation process and has years of experience in the business. This insures you receive the best possible results.
Electro Polish offers high quality stainless steel passivation services for business. You can depend on receiving the right coating for your materials and we offer documented certification upon request.
