冷镦钢Al/Ti复合脱氧工艺优化及夹杂物控制研究OA

To address the issues of clogging in continuous casting nozzles and insufficient mechanical properties caused by coarse Al2O3 inclusions in traditional aluminum deoxidation processes for cold heading steel,this study innovatively proposes a stepwise Al/Ti composite deoxidation process.Through scanning electron microscopy(SEM),metallographic characterization,and mechanical testing,the results demonstrate that the composite deoxidation process generates Al-Ti-Mn complex inclusions with an average size reduced by 30%compared to traditional Al2O3 inclusions,and the number of macroscopic inclusions in the continuous cast billet decreases by 45%.Additionally,the Al/Ti composite deoxidation enhances the nucleation of intragranular ferrite and optimizes the interfacial bonding between inclusions and the matrix.This leads to a significant improvement in ductility:the elongation after fracture increases from 30%to 38%,and the reduction of area rises from 56%to 68%.The clogging rate of continuous casting nozzles is notably reduced by 60%.The research reveals that the Al/Ti composite deoxidation effectively regulates thermodynamic equilibrium and synergizes with kinetic mechanisms.By leveraging heterogeneous nucleation,it suppresses inclusion coarsening,achieving both dispersed inclusion distribution and a synergistic enhancement of strength and plasticity.This study provides theoretical insights for optimizing cleanliness control and mechanical performance in cold heading steel production.