Effect of Scale Formation on Copper Enrichment Behavior in Continuously Cast Slab

摘要

Copper enrichment behavior in continuously cast slab induced by scale formation during continuous cooling was experimentally investigated,and the effects of initial slab surface temperature and oxygen potential in atmos-phere were discussed.The results showed that a loose scale adhered to the substrate was formed in H2 O-N2 atmos-phere at higher slab surface temperature compared to a gap formed between the scale and the steel substrate after continuous cooling in H2 O-O2-N2 atmosphere.Under the condition of continuous cooling in H2 O-N2 atmosphere, the copper enrichment occurred both within the loose scale and at the scale/steel interface with simultaneous Ni en-richment near the interface at higher slab surface temperature.The combined effects of the loose scale and nickel en-richment were thought to promote the back-migration of Cu-rich phase from the interface and occlusion within the scale layer.While in H2 O-O2-N2 atmosphere,the Cu enrichment was found on the steel side and the formed gap pre-vented the migration of Cu to the scale.