Processing Temperatures & Mass Loss of Vapor Corrosion Inhibitors

Vapor corrosion inhibitors can be more volatile during elevated processing temperatures. It is critical that amount of VCI mass loss is engineered into the final product design. This paper focuses on a study where different vapor corrosion inhibitors are tested for mass-loss at different temperatures by use of TGA; and how this may affect corrosion inhibition level of the end-product. The paper also provides some critical considerations for manufacturing steps to improve application processes and final product quality.

Engineering metals are all unstable on the earth in the environment of oxygen, water, and warm temperatures, because they tend to form more stable compounds to lower their energy by spontaneously reacting with the surrounding environmental species.¹ The damage or deterioration of metal due to this reaction is called corrosion. Additional accelerating factors to this process may include rain, snow, wind, dirt, UV, heat, etc.² According to the 2016 NACE IMPACT study, the global cost of corrosion is ~ US$2.5 trillion in 2013. However, 15%~30% of the corrosion cost could be saved by utilizing nowadays available corrosion control technologies, which means US$375 ~ US$875 billion could be saved globally.³

One of the traditional corrosion protection methods for metals during transport and storage is to use coating or oils. But it has its disadvantages and limitations. The oily coating on metal surfaces needs to be removed before painting or welding, which is an extra step for end-users, rather time-consuming, and raising the cost. There are also some hard to reach spaces such as crevices and surfaces of complex-shaped articles that are difficult to apply coatings.⁴ Additionally, coating systems could fail from prolonged environmental exposure and deterioration through UV radiation, moisture, chemical or biological agents, abrasion, water freezing and thaw cycle, etc.⁵ New technologies that involve volatile corrosion inhibitors (VCIs) packaging materials keep evolving over the past decades to meet these challenges.