The importance of material selection cannot be stressed enough.

With the equipment comes the material of the equipment, and every material is prone to corrosion in some way.
For most fields such as defence, oil and gas, automotive, and marine, the qualification tests for the material selection begin and stop with the mechanical properties and composition.
There is not even a mention of the possible corrosion phenomena for that particular material.
This results in ‘surprises’ when there is a serious failure. Only after that are the corrosion investigations carried out and modifications done.
However, by that time, it may be too late for some.
Hence, it is necessary that the concerned personnel in the industries do not cut costs where corrosion is known to be an issue.

What is Corrosion Planning?

It is critical to begin a “CORROSION PLANNING” to ensure that the corrosion risks of every material that is qualified, and every component that is bought are noted BEFOREHAND.

The possible areas of corrosion, environment of exposure, critical mechanisms, past studies, and required non-destructive corrosion testing should be identified. There are terms such as critical reliability variable (CRV) and integrity operating window (IOW), as given in API 584 and 970.
There must be a step where the corrosion risks are listed out for each component, no matter how small. The risks include not just the individual corrosion properties, but also the interaction between the various components.
The possible crevice locations should be mentioned in the print. The issues that may result during exposure to operating medium should be listed.
The types of corrosion seen previously should be mentioned and the risks must be labelled from high to low in the entire component.
A simple example is the corrosion planning for a lead acid battery and aboveground storage tanks.

Further requirements of the planning

Just the plain label of ‘This material has a high corrosion resistance’ is not enough. 

What does it mean? What are its corrosion potential and corrosion current density in the operating medium? What is its mpy in that operating medium?
It is essential to integrate the research aspects with the industrial requirements to arrive at the complete picture, as discussed in this free webinar.
If such aspects are included in the initial stages of material selection and product planning, the industries will be ready for any untoward incident that may happen. 
In most cases, they may even be prevented.
An example of this is API 970 which talks about a corrosion control document for every facility. This includes concepts such as corrosion loops.

Would you like to test your corrosion knowledge now?

Click here for the list of quizzes!

😀Happy learning!😀

Leave a Reply

Your email address will not be published. Required fields are marked *