CONTINUOUS CASTING METHOD FOR MEDIUM CARBON STEEL PREVENTING CRACK OF SLAB BY MONITORING HEAT FLUX OF MOLD COPPER PLATE

摘要

PROBLEM TO BE SOLVED: To provide a continuous casting method for medium carbon steel where the taper ratio TR [%/m] of short side mold copper plates 11, 11 can be introduced into a proper value on a clear judgement standard, and further, the uniform growth of a solidified shell is promoted, so as to prevent a slab crack and breakout caused by the crack.;SOLUTION: A short side heat flux qt [MW/m²] and a long side heat flux qc [MW/m²] are measured, so as to obtain a heat flux ratio qt/qc[-]. It goes back from the present time t [sec] as the time at which the heat flux ratio qt/qc[-] has been obtained, and the average heat flux ratio Ave(qt/qc)[-] from the time t0 [sec] before a prescribed time Δt[sec] to the present time t [sec] is calculated. Whether the expression (1): 0.85≤Ave(qt/qc)≤1.15 is satisfied or not is determined, and, when it is not satisfied, the taper ratio TR [%/m] of the mold copper plate on the short side is increased/decreased so as to satisfy the expression (1).;COPYRIGHT: (C)2009,JPO&INPIT