Surface cracking prediction method of continuous casting slab

摘要

PROBLEM TO BE SOLVED: To provide a method for predicting a surface crack where the surface crack of a slab caused by the dynamic conditions in a secondary cooling zone of a continuous casting machine and deterioration in the ductility of a steel at high temperature can be accurately predicted without requiring the two-dimensional measurement of the temperature in the slab surface and also without using an expensive calculating apparatus.;SOLUTION: When a steel is subjected to continuous casting, the temperature distribution in the width direction of a slab surface is measured in a secondary cooling zone of a continuous casting machine, a temperature peak-valley difference in a peak-valley section of the height of surface temperature, ΔT(L)(=ΔT_E2) is equal to or more than a temperature difference at which the surface thermal stress of the steel decided from the temperature peak-valley difference ΔT(L) reaches a value exceeding the surface crack generation critical stress in the temperature within the peak-valley section, and also, it is predicted that, when the ductility reduction temperature region of the steel is present within the peak-valley section, a surface crack is generated at the slab.;COPYRIGHT: (C)2009,JPO&INPIT