Corrosion in daily life - Steel frames Looking at LinkedIn, corrosion may feel like an extremely intricate issue seen in large industries. However, looking around, we can see corrosion everywhere! Where was this photo taken? The photo above is of a steel frame attached to a balcony.  The part shown here is the bottom part of the frame. The coatings for such steel parts usually serve the purpose of moderate corrosion protection and more of aesthetics. If you observe, the thickness of the coatings also does not seem to be a lot. Why did the coating degrade? When it rains, the rainwater collects on the bottom of the frames.  This degrades the coating. At the places where it is not perfect anyway, the underlying steel is free to corrode. Most importantly, corrosion is more severe at the edges. It is severe enough to chip off the material entirely. That point is a prime site for crack formation and breaking of the frame. Have you seen such corrosion in your balcony fram...

Need for 'CORROSION PLANNING'  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 componen...

Corrosion is a complex subject. It is difficult to pick and choose the starting point. It is very easy to spiral into a confused state of mind if the right resources are not available. Hence, I write this blog post to list out a few books which are great if you are a corrosion enthusiast. Here goes - 1. Corrosion Engineering by Mars. G Fontana          I love this book and I always refer to it for my work. 2. Peabody's control of pipeline corrosion -  3. Corrosion engineering - Principles and practice - Pierre Roberge The website www.corrosion-doctors.org has a more extensive list of corrosion articles. Other than that, there are online corrosion magazines which you can access - 1. Materials performance -  www.materialsperformance.com 2. corrosionpedia.com 3. CORROSION journal  meridian.allenpress.com/corrosion -  it has a few open access articles. Check out these resources as a starting point!

Corrosion is a serious issue. However, corrosion engineers are rarely asked about it during the designing of components. It is only when the components fail that people remember there are people who have studied corrosion for their whole life and would provide a solution. The design problems are really quite simple, and the loss of money could have been avoided had the company bothered to involve a corrosion engineer in the first place. Let me illustrate this with an example of a factory near the sea. Suppose a mild steel pipe is fitted inside the factory to transport 1 wt. % hydrochloric acid. The engineer has a choice between selecting pipes of 5 mm and 10 mm thickness. To save money, they go for the pipe with the 5 mm thickness because it has been 'successfully used by the other customers'. Over the course of a year, it is seen that the pipe has started leaking at certain places. Further investigation reveals that those sections have thinned to half of their thickn...

I recently moved to a new house. As expected, there was a lot of cleaning up to do. One of the tasks was the cleaning of the washbasin. Usually, the drain is a circular part with  5 to 6 holes for the water to flow out. What I saw was this - I have not had a chance to analyse the material of the drain. However, a quick search tells me that this is most probably stainless steel. The water that this drain is exposed to is the bore water. Thus, the drain has encountered a lot of chlorides. There is general as well as localized corrosion. The damage started off as a simple process of pitting. Pitting due to chlorides is one of the most common headaches for poor stainless steel. They break the passive oxide film, and reach the underlying fresh iron. This iron then reacts with the usual suspects (ions, oxygen, water) and forms what we see as the rust. As can be seen in the picture, the thin sections of the drain between the holes have disappeared in three places. This may have h...

Corrosion is the journey of an element from its most active form to its most stable form.  The birth At the place of its birth, inside the earth, an element such as iron comes into contact with atmospheric oxygen, chlorides, sulphate, and moisture. and is quite happy to remain in peace with them in the form of Fe 2 O 3 , Fe 3 O 4 , FeCl 3 and such. The growth It is then extracted and made to go through a number of processes which separate it from the ions and bring it to its elemental form. It is then put into use to make steel, where it coexists with carbon, manganese, chromium, and other alloying elements. The interaction However, iron has three electrons that it desperately need to give away. That is exactly what it does the moment the steel is brought out from the factory and put outside in the shed. Iron is more than happy to reunite with its old buddies - oxygen and moisture. It gladly gives away its electrons to them and returns to its peaceful state of Fe 2 O 3...