(7B-4) ADVANCED CASTING TECHNOLOGIES OF ROUND BILLET CASTER IN SUMITOMO METALS

摘要

The advanced round billet casting technologies have been developed at Wakayama Steel Works. The round billet casting is efficient in comparison with bloom one, because round billets are directly supplied to seamless pipe mill without blooming (billeting or rolling) process. In the round-shaped billet, transverse surface cracks and centerline cracks tend to appear especially in case of low alloy steel containing Cr or Nb. As-casting billets could not be sent to seamless pipe mill directly because of these defects.