A New Large Bloom Caster for High Grade Steel at Pohang Works of POSCO

摘要

In order to increase production amount of the high grade steels and improve their quality, the new bloom caster of section size, 300X400mm~2 was built at Pohang Works of POSCO at Nov. 27, 2002 with quality improving equipments such as mold EMS, soft reduction units, ECLM, air mist cooling, hydraulic oscillator, tundish plasma heater, etc. The operational results are as follows. 1) Normal operation to cast 22 charges per day was accomplished for 16days. 2) Annual production amount gradually increased to be 731,000 ton, 786,000 ton, 950,000 ton from 2003 to 2005 and sequence casting ratio with tundish exchange also increased 5.7, 6.4, 11.4chs/day from 2003 to 2005. 3) Nonmetallic inclusions, surface defects, and center segregation were much improved. 4) Production amount of the high grade steels at the new bloom caster has been about double at the old bloom caster. 5) Ultra fine tire cord steel, engine valve spring steel, and ball bearing steel for an automobile are being produced commercially.