A STEEL COMPOSITION FOR PRODUCING SUPERIOR QUALITY CONCAST BILLETS FAVOURING REDUCTION OF OFF-CORNER INTERNAL CRACKING AND A METHOD THEREOF

摘要

A steel composition for producing superior quality concast billets at high speed comprising, Carbon: 0.20-0.25%; Sulphur:0.03%(max); Silicon :0.20 to 0.30 %; Manganese :at least 0.75, selected such that the Mn/Si ratio is maintained at least 2.9 and Mn/S ratio at least 25.0 and or alternatively Carbon: 0.4-0.6%; Sulphur:0.03%(max); Silicon :0.20 to 0.30 %;Manganese :at least 0.80, selected such that the Mn/Si ratio is maintained at least 3.3 and Mn/S ratio at least 26.7 and adapted for reducing the formation of Off-corner crack, blow holes/pin holes and breakout and a method casting seamlessly production of superior quality concast billets at high speed with increased productivity. Said method involving velocity of water cooling in mould is increased to about 11.5 m/sec, providing mould foot roll and modified below mould spray jacket and providing of high upper taper of 2.4%, in multi tapered mould