It is estimated that on an average corrosion eats into about 5% of a country’s GDP – having a negative effect on the economy’s exchequer, affecting growth and sustainability. Corrosion also has an implication on environment and leads to wastage of resources, lost production & injury of personnel. Today companies are aware of the impact of corrosion on their bottom-line and hence are open to adopt corrosion control methods. However, according to Prof A S Khanna, Department of Metallurgical Engineering and Materials Science, IIT Bombay, the effort is still considered as extra expenditure. In this interaction, Prof Khanna highlights the importance of corrosion protection and deliberates on various methods to mitigate corrosion.
As an expertise on corrosion control & prevent, could you please explain the important of corrosion protection for industries?
All industries using steel and other corrosion prone metals and alloys such as aluminum, etc. need to protect their asset from corrosion. The corrosion process itself has to be identified first. Whether it is due to atmosphere around it or due to process taking place? Whether toxic chemicals or acids or high temperature is involved in the process? Usually there are different approaches are to combat corrosion: Protection by coatings, cathodic protection or use of inhibitors chemicals. The first two methods protect the corroding metal as a barrier while use of inhibitors modifies the environment and hence protects the overall corrosion. At high temperatures usually special high temperature coatings are employed.
Which industries are the most susceptible to corrosion?
Oil and gas producing companies right from offshore platforms, refineries and petrochemical plants are the most corrosion prone industries. Chemical industries dealing with the manufacture of toxic acids or use of such things as intermediates are severely affected by corrosion. Power plants especially coal based are prone to corrosion both from waterside as well as from fireside.
What are the main causes of corrosion in industries?
There can be several causes of corrosion in industries. But the main causes can be listed as:
1. Poor material selection
2. Either not employing corrosion protection measures during design or poor corrosion control strategy
3. No online monitoring or periodic maintenance, which is one of the prime requirements today, even if a good corrosion mitigation methodology has been employed
In general, it can be said that many industries are lacking to employ corrosion management in their plants.
What are the commonly used products/procedures for detection, protection and prevention of corrosion?
There are many methods to control corrosion. Various kinds of organic paint coatings are used to take care of external corrosion of steel structures in highly aggressive plant environment. Specialised internal organic coatings are used as linings for storage tanks, pipelines etc.
Several inhibitors are used to curb the corrosion in aqueous environment and power plants, water pipelines and crude and gas transportation pipelines.
Cathodic protection is a technique used to control the corrosion of underground pipelines
Are these corrosion protection methods same across the industries or they differ from industry to industry?
In general, corrosion methods are same across the industries but definitely methodology and strategy varies with the environment to which metals are exposed.
Are you seeing an increase in awareness about corrosion protection in industries?
Yes, there is increase in the awareness about corrosion protection measures. However, the effort is still considered as extra expenditure. People do not think about this right from design, go with cheap methods of corrosion mitigation.