We all know that industrial processes can be tricky—but what if I told you there was a process that could ensure your parts and components work reliably, as expected? That’s where steel passivation comes in. Industrial companies have been turning to this fantastic method of protecting stainless steel against corrosion and oxidation for years.
But what exactly is this method all about, how does it work, and why should you consider implementing it into your industrial plant operations? Learning all about this process and how it can benefit your business will allow you to utilize it to the best of your abilities.
What is Passivation?
Simply put, the passivation process happens when materials like stainless steel are protected from rust and corrosion. Its primary goal is to reduce the deterioration and decay of material by protecting it from its environmental reaction. The result is an increase in the material’s lifespan because its corrosion-resistant properties have been improved significantly.
Metal passivation is the most common process that many industries use, especially in facilities where products are exposed to harsh environments. The process is mainly used on stainless steel but can also be applied to other metals such as aluminum and nickel or nickel alloys.
The Process of Passivation for Stainless Steel
As mentioned above, stainless steel is the most common metal that undergoes this post-fabrication process. Even though stainless steel is already resistant to rust and corrosion because it is an iron alloy, long-term exposure to moisture, heat, and other substances can cause the steel to oxidize. This process is implemented to restore the stainless steel’s surface while improving its corrosion resistance performance.
The passivation of stainless steel uses nitric acid or citric acid to remove free iron from its surface. This chemical treatment creates a protective layer or a film, which makes the metal less likely to react with air. Therefore, corrosion is also avoided. It’s worth noting that today’s industry standards, ASTM A967 and AMS 2700, represent the widely used standards for passivated stainless steel.
The Different Types of Passivation
According to the industry standards for passivation stainless steel, there are three types of this process to choose from. Each type will depend on the chemical that’s going to be used.
The three types are as follows:
- Citric acid
- Nitric acid
- Nitric acid with sodium dichromate
The type of stainless passivation used will depend on the specifications and requirements of the client. Since each has its benefits and drawbacks, it’s essential to know the purpose and application of the material before making a final decision.
Why Should You Passivate Stainless Steel?
This post-fabrication process is also used as cleaning passivation for the maintenance of stainless steel parts and components. But it’s also a post-fabrication method for newly-machined stainless steel equipment or surfaces.
Some benefits to take advantage of:
- Extend the life of the product
- Remove any contaminants from the metal’s surface
- It provides a chemical film barrier to protect against rust
- Reduces the need for future maintenance
Difference Between Derouging & Passivation
“Rouge” refers to the brownish stain in the pipes and tanks. It’s a corrosion product that can affect the various parts of a system. Cleaning the affected surfaces periodically can maintain good product quality. It’s also known for removing metal oxides and hydroxides from surfaces.
These two processes often go hand in hand since the standard practice is to passivate the surface, parts, or components to enhance its protection against corrosion. It’s why many industries prefer to use both processes together.
Protect Your Stainless Steel Equipment from Corrosion & Rust
Ensuring the protection of your equipment is a must in industries where corrosion and rust are predominant. If you’re looking for a reputable specialized cleaning service, Cleansol LLC offers derouging and stainless steel passivation for the pharmaceutical, biotechnology, and semiconductor industries. Contact us today to learn more about our other services as well!