METHOD AND APPARATUS FOR DETECTING BREAKOUT IN CONTINUOUS CASTING, CONTINUOUS CASTING METHOD OF STEEL USING THE APPARATUS, AND BREAKOUT PREVENTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus which accurately detect the occurrence of the breakout of a slab in the continuous casting of molten steel.;SOLUTION: The method for detecting breakout in continuous casting comprises: measuring a heat flux q 1 input to a solidification interface during the period of time when the molten steel in a mold in continuous casting reaches a mold outlet from a molten steel surface; obtaining a normal heat input q 2_req to the solidification interface due to molten steel flow in the mold in a normal state by the following equation (1); obtaining a heat flux profile observed until the molten steel reaches the mold outlet from the molten steel surface for difference between the heat flux q 1 and the normal heat input q 2_req to the solidification interface; and determining presence/absence of the risk of the occurrence of the breakout on the basis of a degree of solidification delay RS calculated by an overall heat flux Q2 corresponding to an area of a portion located above a line connecting the minimum point of the heat flux profile and a local heat flux value at the mold outlet, wherein q 2_reg=h×Δθ (1), q 2_reg: heat input (J/s×m₂) of the steady solidification interface, h: the heat transfer coefficient (J/s×m²×°C) between the molten steel and the solidified shell, and Δθ: the superheat degree (°C) of the molten steel.;COPYRIGHT: (C)2011,JPO&INPIT