Mould for the continuous casting of steel - using formula for obtaining tapered mould walls to prevent fissures in cast billet

摘要

In the continuous casting of steel billets, where the internal cross-section of the mould is tapered towards the base to match the contraction of the steel during cooling, the relative redn. in the peripheral length DELTAU, w.r.t. the initial peripheral length Uo in the region of the surface of the molten metal, in percent, corresponds almost with a parabola with the relationship: where Ko is 0.12-0.18; f is 0.00 to -0.00015; Vg is the casting speed in cm/min, and 1 is the distance in cm from the surface of the molten metal in the mould to the relevant internal cross-section. Within the specified range, Ko pref. increases with the carbon content of the steel and is at the bottom of the range in the case of soft steels. Prevents cracks and pressure in the surface of the steel and avoids the break-out of the molten core through the solidified skin. Pref. f = -0.0000966 and KO = 0.165 and the bore of the mould pref. consists of several contiguous steps with progressively decreasing conical taper.