Thermo well -Caustic incinerator

[NirvaanB]

Good day,

My first post (of many).

The attached is a thermo well from our caustic incinerator that was sent for metallurgical investigation. The outcomes are that this is due to carburization.

Similar failures occurred in the past on other thermo wells in the same application in the caustic incinerator. This problem came over a period of time and worsens as time progresses. Numerous materials such as Hastelloy C, Inconel 600, and Inconel 825 etc. were tested in the environment and failed. The unit runs at 900'C.

My questions:
Is there a direct solution for this problem?
What materials can you recommend?

 

[Goahead]

Are you sure you need a metallic body? Would not "low-porosity refractory materials, [that]
minimize molten salt contact with refractory walls" be more suitable? (this is from a manufacturer leaflet of caustic incinerators).

http://www.welding-advisers.com/