Research on Secondary Cooling Technologies for Continuous Bloom Casting

The secondary cooling scheme previous employed in continuous bloom caster was of following inadaptabilities for production of rail steel, such as the density of the secondary cooling and water distribution in secondary cooling zones. Therefore, the secondary cooling control scheme suitable for rail steel was developed on the basis of the variation of hot ductility with temperature and the distribution of strand surface temperature in secondary cooling zones, which improves internal quality of bloom heavy rail obviously. The operation shows that the center looseness and central segregation and shrinkage cavity are≤1.0, meanwhile, central segregation index of carbon is≤1.05, and the area ratio of equiaxed zone is≥30%. Internal quality and mechanical performance of the rails produced from continuously cast blooms have met the requirement of high-speed 350 km/h tracks.