At Wakayama Steel Works of Sumitomo Metal Industries, tube rounds have been supplied by break down process of concast blooms. For the further drastic rationalization of the process, direct tube round casting trials have been carried out.
(1) Round billet casting trials have been carried out by minor changes of the existing curved and vertical type slab casters.
(2) Surface and internal quality of round billet have been found excellent.
(3) Round billets may be rolled to seamless tubes without surface conditioning.
(4) To reduce the center porocity, enough care must be taken, especially for super heat in tundish and casting speed.
(5) Equiaxed crystal zone of cast round billet have greatly increased by newly developed R.M.S. (Rotating Magnet Stirrer).
