Definition & Source of Primary & Secondary Corrosion Inhibitors

[fcesar]

I'm looking for the definition of "Primary Corrosion inhibitor" and the source.
Common sense tells me that primary corrosion inhibitor is the product you use to treat your primary corrosion problem. Secondary corrosion inhibitor, as the word say, is the product used as “safety” to prevent other types of corrosion other then your primary. "Let you sleep at night" type
The chemist (a contractor) treating our industrial water system is trying to tell me that primary corrosion inhibitor is a "list of products" such as PO4, poly phosphate, silicates, etc...
From what I understand, those products are commonly used as primary corrosion inhibitors, but that does not make them ALWAYS the primary, it depends on the use you are making, not the product itself.
I'm not a chemist and I'm being tagged as "I don't know what I'm talking about".
Can someone help me find the definition of primary and secondary corrosion inhibitors and most important, the source or reference that I can bring to a meeting with this chemist.
Please correct me if I'm wrong.
Thank you

 

[Astronuc]

This paper mentions primary and supplemental (or secondary) agents.

http://www.nace.org/nacestore/assets/ConferencePapers/2000/00659.pdf

The primary inhibitors directly affect the galvanic or reduction/oxidation reactions - e.g. reducing/oxidizing agents or film formers.

The supplemental or secondary inhibitors affect intermediate or indirect steps. e.g. pH/buffer, conductivity of the solution, . . .

Here is a nice tutorial on corrosion -
http://www.gc3.com/techdb/manual/corrfs.htm

 

[ravenprp]

A primary corrosion inhibitor is a substance or product that is specifically designed and used to prevent or slow down the corrosion process in a particular system or environment. These inhibitors are often applied directly to the metal surfaces to form a protective layer or barrier, preventing the corrosive agents from reaching the metal.

Primary corrosion inhibitors can be sourced from various materials, such as organic compounds, inorganic compounds, or even coatings. Some common examples of primary corrosion inhibitors include phosphates, silicates, amines, and nitrites.

On the other hand, secondary corrosion inhibitors are substances that are not specifically designed for corrosion inhibition but can still provide some level of protection against corrosion. These inhibitors are often used as a backup or additional protection in case the primary inhibitor fails or is not effective enough. Examples of secondary corrosion inhibitors include oxygen scavengers, pH adjusters, and biocides.

The source of information on primary and secondary corrosion inhibitors can be found in various references and standards, such as the NACE International's "Standard Recommended Practice - Control of Corrosion on Offshore Production Platforms and Pipelines" or the ASTM International's "Standard Guide for Corrosion Inhibitors in Oil and Gas Production". These resources provide comprehensive information on the types, functions, and applications of corrosion inhibitors. Additionally, consulting with a corrosion expert or a reputable chemical supplier can also provide valuable insights and information on the topic.