ANALYSIS AND CONTROL OF NOZZLE CLOGGING IN LOW-CARBON AL-KILLED STEEL
Analysis of the clogs on the submerged nozzle shows that the clogs on the inner wall of the nozzle are in the form of flakes,spherical blocks,and polyhedra,with a size of 5～20 μm;it is mainly formed by the adsorption and enrichment of small-sized Al2O3 in the steel liquid on the inner wall of the nozzle and mutual sintering.The clogs on the bottom of the outer wall are polyhedral and layered,with a size of 20 μm;it is formed by the continuous growth of alumina inclusions caused by secondary oxidation during the pouring process.By using high carbon pulling at the endpoint of the converter,the average oxygen content at the endpoint of the converter is reduced to 5.50×10-4.By strengthening the protection of casting,the average total oxygen content of the ladle steel is reduced to 40×10-6.After taking optimization measures,the amount of Al2O3 inclusions is effectively reduced,secondary oxidation is avoided and the castability of the steel is significantly improved.
万方数据
维普
