nozzle clogging with ladle shroud
nozzle clogging with ladle shroud
(OP)
hi,
we are casting plain carbon grades in our continuous cating machine with 0,17-0,20 % C; 0,70-0,80 % Mn; 0,15-0,20 % Si; 0,030 % S; 0,010 % P. No Aluminium and Calcium wire addition is applied in ladle furnaces. Only 30 kg of Aluminium is added during EAF tapping.
During open casting, we do not have any probem of castability in tundish zirconia nozzles. However, when we apply ladle shroud between ladle and tundsh, clogging starts in our 18 mm zirconia nozzles. Even, we have very low Aluminium and Calcium content in our steel (0,003 % Al; 0,0005), analyze of clogging matrix shows alumina. We are searching the reason.
we are casting plain carbon grades in our continuous cating machine with 0,17-0,20 % C; 0,70-0,80 % Mn; 0,15-0,20 % Si; 0,030 % S; 0,010 % P. No Aluminium and Calcium wire addition is applied in ladle furnaces. Only 30 kg of Aluminium is added during EAF tapping.
During open casting, we do not have any probem of castability in tundish zirconia nozzles. However, when we apply ladle shroud between ladle and tundsh, clogging starts in our 18 mm zirconia nozzles. Even, we have very low Aluminium and Calcium content in our steel (0,003 % Al; 0,0005), analyze of clogging matrix shows alumina. We are searching the reason.





RE: nozzle clogging with ladle shroud
RE: nozzle clogging with ladle shroud
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Plymouth Tube
RE: nozzle clogging with ladle shroud
Yes - examine refractory compositions. What is heat size for 30kg deox add? Soluble O may be attacking then oxide remains in liquid.
RE: nozzle clogging with ladle shroud
Also, consider adding argon purge in ladle to tundish shroud (preferably just below ladle slide gate) if its not there already.
RE: nozzle clogging with ladle shroud
During CCM operation, Alumina type ladle shroud is used, and faced with nozzle clogging. When we take out ladle shroud from operation, no clogging occurs.
RE: nozzle clogging with ladle shroud
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: nozzle clogging with ladle shroud
I agree with MCGUIRE, but be very careful with calcium treating grades that have any significant sulfur level - CaS can cause more problems that aluminates.