METHOD FOR CLASSIFYING CONTINUOUSLY CAST SLAB

PROBLEM TO BE SOLVED: To enable classifying to each distributing part with non-metallic inclusion value in a continuously cast slab at early time. SOLUTION: A sample sucking molten metal in a tundish at 100-200mm above a tundish nozzle or the molten metal in a mold at 50-100mm below a meniscus into a metallic mold and rapidly cooled, is taken by using a suction type sampler. As necessity requires, the hot working is applied to the sample with a press or a hammer. Thereafter, the inclusion value is measured with 10-100MHz ultrasonic wave by using an ultrasonic detector. The continuously cast slab is classified to each distributing part at the early time by collating the measured non-metallic inclusion value with the standard of the inclusion value to each distributing part.