Heat resistant material

[Salvatio]

Hi, currently the diesel fired burner tubes inside our furnace seem to have deformed, and looked as if it has degraded away. The tube end looks like a flower, with its edge sharpened. The material is stainless steel 310, as provided by the supplier.

Is 310ss a suitable material? Could the deformation due to creep? What would the alternative materials be, if cost would be a factor?

 

[metengr]

Salvatio;
What type of furnace? What are the service conditions for the 310 ss tube material - meaning what flows on the inside of the tubes what environment is on the OD surface of the tubes?

From what you described it could be high temperature corrosion damage. How long have the tubes been in service? What type of diesel fuel do you burn?

 

[Salvatio]

it's from batch annealing furnace's heating hood burners. All of the burners are affected. It's been in service for about more than a year. I'll try to find out the type of diesel. The burner tube basically directs the fire inwards. I'm not sure the exact temperature at the burner itself, but the temperature within the heating hood is approximately 850 degC.

I've talked to some suppliers, and I was told that 314ss could replace the 310. Is that true?

 

[metengr]

The description you provided sounds like high temperature corrosion. You might want to contact rolled alloys. I have dealt with these folks and they have an elevated temperature alloy just for this type of application. I would make sure that you have information on the fuel composition, this will be necessary;

http://www.rolledalloys.com

 

[arunmrao]

Unburnt carbon during combustion of diesel leads to deposition of soot and other products on the tube. This deposition becomes the active source for carbon pickup,in the 310 material,eventually leading to brittle failure. In my opinion,310 is suitable at 850C if this problem of carbon pickup can be avoided.There is no point in going for higher alloys, a switch over to some proprietary alloy or a lower grade will suffice.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

 

[Salvatio]

arunmrao,
yes, we do find large bulk of carbon deposition at the nozzle surrounding. We've tried to install filters for the diesel, but yet to see any improvements. Proprietary alloy..such as 310L?