Recovery of metal parts affected by corrosion

Recovery of metal parts affected by corrosion

Is it possible to recover metal parts affected by corrosion? Frequently our clients ask us whether it is possible to recover any of their metal parts affected by corrosion. In order to answer this question, we must first understand the effects of corrosion on metals. Corrosion involves the deterioration of a substance, in this case the metal, converting the iron within the steel into another substance that does not have the desired characteristics, such as resistance or hardness.

The product we are most familiar with when corrosion occurs is iron oxide (ferric oxide), which consumes and degrades metal. In addition, we can distinguish two types of corrosion based on:

• if the loss of material occurs in defined places on the surface (localized corrosion)
• the effect is uniform over the entire surface (widespread corrosion).

How to differentiate generalized corrosion from localized corrosion?

The images shown belong to enclosure parts from one of our clients severely affected by corrosion. In them we can see a clear example of the two types of corrosion mentioned and get an idea of ​​the effects caused. On the one hand, the image 1 shows how the widespread corrosion, where you can see the appearance of ferric oxide over the entire surface. The old coating has completely disappeared and the metal looks slightly deteriorated.

On the other hand, the image 2 shows the devastating effects of localized corrosion. Although the image shows the same part as the image 1 once it has been shot blasted, a total perforation of the metal can be observed in a specific area of ​​it. It is because the anodes and cathodes have remained in that area of ​​the metal for a longer period of time, causing the corrosion to attack in the form of pits until it completely pierces the steel.

Therefore; Can a rusty metal part be reused?

It will depend on two variables fundamental:

• The degree of oxidation / level of deterioration of the piece, which is a clear indicator of the degradation that the material has suffered and determines the possibility of its reuse or not.
• The procedure for the recovery of said metal parts affected by corrosion, It must be meticulous and professional. In this way, the metal surface is completely free of rust, all kinds of contaminants and sharp edges for subsequent abrasive cleaning. (If you want to know more about the importance of abrasive cleaning, click here)

Finally, and to ensure a long useful life of the materials, the coating has to be carried out with first class materials. In this case, it was decided to carry out the corrosion protection with the thermoplastic Plascoat PPA 571 from Axalta, creating a protective layer or membrane that isolates the entire metal surface from the environment to extend the useful life of the bars even more than 20 years. The final result has been the following:

Result of the recovery of metal parts affected by corrosion

If you want to know more about corrosion, we invite you to read the following article:

What is corrosion?