Castability control of high Al steel 38CrMoAl during continuous casting

HighAl content in 38CrMoAl(Al=0.7%-1.1%) is liable to cause nozzle blockage in continuous casting.Shape control of Al₂O₃ inclusions is needed to ensure the castability of molten steel.The results of thermodynamic calculations and experiments demonstrate that high content in the steel has strong reducibility to SiO₂ in slag even with a small quantity,and Al₂O₃ with a higher melting point can be changed to spherical calcium aluminate inclusions with a lower melting point through slag infiltration during converter tapping instead of the conventional calcium wire feeding process.Meanwhile,the slag-steel reaction,which may cause an increase in the amount of inclusions,can be avoided by using tundish covering fluxes based on CaO-Al₂O₃ with low SiO₂ content.The results of industrial tests show that the steel's cleanness is higher and the castability of molten steel is better.The nozzle has no blockage after five heats of continuous casting steel.