Erosion-corrosion issues in boiler applications

[sivakumar]

Dear Forum members:

I wish to know the latest developments in terms of materials for combating erosion-corrosion issues in boiler applications. As i understood from discussions with experts from a leading powder manufacturer that Cr3C2-Inconel is the latest material, having a potential to replace fine grained Cr3C2-25NiCr and i wish to know your field experience on the above materials. And your thoughts on potential materials for such applications will be of immense help to my research..

With advance thanks...

Sivakumar

[MichiganMan]

Corrosion-erosion of boiler tubes cannot be reduced to a simple "best material". There are a wide variety of factors that play into best selection including, but not limited to:

1) What is the fuel in this boiler? Most likely you are referring to coal, but other fuels introduce different issues.
2) What is the composition of the atmosphere inside the boiler? Inconels are often good selections, but there are pitfalls that you don't want to fall into.
3) Where in the boiler are you talking about? Corrosion-erosion behaviors and solutions may be very different for instance in sootblower lanes as opposed to at the bull nose.
4) Presumably this is for a research paper and not application specific, therefore I would suggest that in general you are on the right track. One thing that cannot be stressed enough is that in most environments the material selection is less important than making sure that the application is executed with a sound quality control plan.
5) **Caution, rumor and speculation**While I have no direct knowledge of them I have heard rumors of some studies being conducted on gradient type coating systems. This requires special equipment and is mostly R&D technology to the best of my knowledge. I haven't looked for any specific papers on it, but if you are trying to assemble a paper on "best technologies" then you may find value here.