YungPlantEng
Chemical
- Jan 19, 2022
- 91
I am looking to evaluate the potential for pack cementation coatings, specifically aluminizing, of C276 to form nickel-aluminides that might be more resistant to the erosion-corrosion and sulfidation/hot corrosion that a spray nozzle experiences while in service.
This spray nozzle sprays sulfurous water (water with high concentrations of chlorides, sulfates) at ~125 F onto a gas stream coming in around 2400 F. From my side it's difficult to confirm the "dominant" mode of corrosion, if any, between hot corrosion or sulfidation from particulates as opposed to dew point corrosion from start-up/shutdown. Also not sure since direct cooling is taking place if the outer metal temperature is actually closer to the dew point of the various acids that can form or if it's well outside that range. Pressures are a few psig above atmospheric
That's just some background in case anyone has direct experience. My initial question is would aluminizing a high-nickel alloy be pointless due to dew point corrosion from startup/shutdown immediately dissolving it? There's not too much literature on nickel-aluminides but my understanding is it's akin to nickel in corrosion resistance against sulfuric.
Thanks for any help! Here's a picture of the nozzle in case anyone's seen something like that before.
This spray nozzle sprays sulfurous water (water with high concentrations of chlorides, sulfates) at ~125 F onto a gas stream coming in around 2400 F. From my side it's difficult to confirm the "dominant" mode of corrosion, if any, between hot corrosion or sulfidation from particulates as opposed to dew point corrosion from start-up/shutdown. Also not sure since direct cooling is taking place if the outer metal temperature is actually closer to the dew point of the various acids that can form or if it's well outside that range. Pressures are a few psig above atmospheric
That's just some background in case anyone has direct experience. My initial question is would aluminizing a high-nickel alloy be pointless due to dew point corrosion from startup/shutdown immediately dissolving it? There's not too much literature on nickel-aluminides but my understanding is it's akin to nickel in corrosion resistance against sulfuric.
Thanks for any help! Here's a picture of the nozzle in case anyone's seen something like that before.