脉冲电磁场凝固组织细化和均质化技术研究与应用进展

由于金属凝固过程中选分结晶的作用,不可避免地会出现成分不均匀现象。连铸过程中由于强制冷却,这种成分不均匀现象更为严重。这不仅影响了铸坯和铸锭后续加工性能,并影响了最终产品质量和性能的均匀性和稳定性。研究和生产实践表明,细化凝固组织是解决成分不均匀性的有效手段。脉冲电磁场因能耗低、施加方便、细晶效果显著,近年来得到了广泛关注,有望成为冶金界广泛应用的凝固组织细化和均质化技术。分别介绍脉冲电流、脉冲磁场和脉冲磁致振荡3种脉冲电磁场凝固组织细化和均质化技术的研究现状和应用进展。

Research progress of grain refinement and homogenization of solidified metal alloys driven by pulsed electromagnetic fields

Inhomogeneous solute distribution frequently occurs owing to solute rejection during the solidification process of metal alloys.The intensity of solute segregation in continuous casting is more serious due to the forced cooling from the sidewall of billet.This solute segregation phenomenon not only reduces the workability of solidi-fied billets and ingots,also severely deteriorates the homogenization and stability of products quality and proper-ties.The grain refinement achieved during alloys solidification shows the potential to approach the homogenization of solidified structure and solute distribution.Recently,the application of pulsed electromagnetic fields to produce grain refinement in solidified alloys has been significantly investigated due to its advantages of saving energy,easy application,significant reduction of grain size,and so on.Several related techniques have been developed and shown the potential to be widely applied in industry to significantly improve the quantity of products.The research status of electric current pulse,pulsed magnetic field and pulse magnet oscillation and their related grain refine-ment mechanism were presented and reviewed,respectively.