PURPOSE: To produce a billet having no internal defects such as shrinkage holes and central segregation by positioning the crater end of the billet at a level higher than the level of the unsolidified steel melt in the billet and press sticking the vacuum cavity.
CONSTITUTION: A drawing speed of a billet or the like is controlled to position a crater end 6 at a level higher than the level H of the unsolidified steel melt in a billet 4 in the case of drawing the billet 4 along a circular locus. A vacuum cavity 8 is then formed between the crater end 6 and the surface 4a of the unsolidified steel melt in the billet. The billet 4 is rolled down by rolling rolls 5 in the position of the crater end 6 and the cavity 8 is thoroughly press stuck. The billet 4 is thereafter corrected straight and level by straightener rolls 7 and is cut to a prescribed length by a cutter.
YANO KOUZOU
TSUCHIDA YUTAKA
SUGAWARA ISAO
NAKADA MASAYUKI
