EVALUATION METHOD FOR HIGH TEMPERATURE EMBRITTLEMENT OF CONTINUOUSLY CAST SLAB AND CONTINUOUS CASTING METHOD FOR STEEL

PROBLEM TO BE SOLVED: To provide an evaluation method for high temperature embrittlement which can make an exact evaluation through measurement using a small number of test specimens in a short period of time, and also to provide a continuous casting method which enables manufacturing of slabs free from lateral crack by using the evaluation method. SOLUTION: The high temperature embrittlement evaluation method of continuously cast slabs is used to evaluate occurrence of lateral crack on continuously cast slabs. A lateral crack susceptibility of slabs is evaluated based on a crack generation critical strain measured in advance by using specimens which have the same steel kind and the same chemical composition with those of slabs under casting and have such a specimen profile as to induce a variety of strain levels by one compression test. Under the continuous casting method, while casting the steel using the continuous caster, a surface temperature of slab at the bending section or the straightening section of the caster is controlled within such a temperature range that the crack generation critical strain measured by the high temperature embrittlement evaluation method stays at 5% or more. COPYRIGHT: (C)2009,JPO&INPIT