CAST IRON BILLET EXCELLING IN WORKABILITY AND PROCESS FOR PRODUCING THE SAME

摘要

A tough cast iron or cast iron billet excelling in workability is provided without enormous thermal energy and prolonged heat treatment. There is further provided a process for efficiently producing the same. In particular, a cast iron comprising a component converted to white cast iron, wherein spherical graphite or elongated graphite is dispersed, the component converted to white cast iron having a composition satisfying the relationships of, in terms of mass%. (%C) <= 4.3 - (%Si) / 3 and C >= 1.7%. In such a cast iron, the spherical graphite is dispersed in an amount of 50 particles/mm<2> or more, or the elongated graphite has a width of 0.4 mm or less and a length of 50 mm or less.