A billet produced by continuous casting having little central segregation, in
particular
a billet of high carbon steel produced by continuous casting, and a manufacturing
method therefor are provided. In the continuous casting billet, the size of the
dendritic equiaxed crystal in a billet central portion is reduced to be not more
than 6 mm. For this purpose, electromagnetic stirring is performed so that the
inclining angle of the primary dendrite within 10 mm of a billet surface layer
is increased to be not less than 10. Furthermore, the mechanical soft reduction
is performed during continuous casting so that the diameter of the center porosity
in the billet central portion is reduced to be not more than 4 mm. Thereby, in
particular in the manufacturing of the continuous casting billet having a carbon
content of not less than 0.6% by mass and a billet size of not more than 160 mm
can be provided a billet in which breaking troubles in wire drawing after rolling
to a rod are reduced by reducing the central segregation in the billet.
