The Application And Practice Of Interrelated Technologies In Revamping Of 1930mm Slab Caster In Baosteel

The No.1 and No.2 CCM of Baosteel were two large slab continuous casting machines introduced from Japan.The designed yield was 4,000,000t per one year. The two CCM were international advanced level at the start of the 1980s.Slabs have been produced over 65 million tons in recent 14 years. The largest yield was 5.305 million tons in 2001.They played an important role in the continuous casting technology development of Baosteel.On the 21st century, continuous casting technology have developed roundly at the side of production quality and enhancing efficiency. No.2 CCM has been running for 15 years since 1989.CCM precision could not be ensured for the major mechanical equipments aging.The technology of electrical equipments were uncultured up to now,so the fault ratio was large and many productions had not been produced any more.CCM equipments couldn't meet the requirements of producing large qualities of high grade steel.Baosteel decided to rebuild No.2 CCM to obtain the aim mentioned above.The rebuilding range include mould,segment, segment draving, mould cooling water, second spray cooling water, electrical and instrument equipments. The offline equipments of mould and segment must be rebuilt as mould and segment have been rebuilt.Water treatment system must be rebuilt in order to meet second spray cooling water.Firstly, we should confirm rebuilding range.On 13m platform,turret, tundish car, DB car were not rebuilt.Cutting machine, deburring machine, marking machine were not rebuilt too.The rebuilt equipments were decided by new process and new technologies. Central new process and technologies:(1)Mould hydraulic pressure oscillation technology can reduce the depth of oscillation marks.(2)Second cooling water automation adjusting technology can adjust the height of spray frames automatically according to slab width,then adjust the width of spry water. This can reach to effect spray purpose and reduce the quality of water.(3)The segment roll diameter have been reduced by decreasing slab bulging.(4) The DB head can be divorced from slab automatically.(5)Mould EMS technology can improve external qualities of slabs, reducing inclusions,pinholes and external cracks.(6)Segment soft reduction technology can improve internal qualities of slabs,especially center cracks and internal cracks of slabs.The rebuilding range include mould, segment, segment draving, mould cooling water, second spray cooling water, electrical and instrument equipments. The offline equipments of mould and segment must be rebuilt as mould and segment have been rebuilt.Water treatment system must be rebuilt in order to meet second spray cooling water.This paper will describe the contrast results before and after the applying new technology.The results showed that EMS technology and soft reduction technology improved external internal quality of slabs.