Development of Large Cross-Section Bloom Casting Process

Daido steel has developed a new caster, which features are semi-continuous, large cross section and vertical type. It was built in July 2004, and named "PHC"(Promising Hybrid Caster). The PHC has characteristics and advantages of both continuous caster and ingot casting process. And the process has the following quality results of the PHC bloom. -1) By applying extremely low speed casting technology, the internal quality of PHC bloom has improved. Its quality level is equivalent to that of the conventional bloom. -2) Variable width mould mechanism has been developed and introduced to PHC. The mechanism has made it possible to cast tapered bloom and greatly improved the internal quality of high carbon grades. -3) Punching press was introduced to prevent the oxidizing of cut section of the PHC bloom during cutting or reheating. The process is very effective to improve the quality of center part of PHC bloom and the rejection ratio because oxidizing of cut section is zero. -4) Shrinkage of the top part of PHC bloom has greatly improved by Top-heater. A s a result, crop loss of top part of Top-heated bloom has reduced by 80 % compared to that of as cast bloom.