Refining the Solidification Structure of TWIP Steel Using Ce-based Inclusions

摘要

The evolution of solidification structure of TWIP steel in a commercial continuous caster has been simulated using a lab-scale casting simulator.Significant refining of solidification structure has been found due to the various inclusions such as oxide,sulfide,phosphide and their complex by addition of cerium in molten steel.Especially,there was a marked grain refinement effect for TWIP steel with 250ppm [P] and 0.3％ [Ce],which can be attributed to the pinning effect of inter-dendritic CeP inclusions.The main contribution of these non-metallic inclusions to the nucleation of austenite steel,and to the pinning of columnar dendrites have been discussed in detail based on thermodynamic and micro-structure assessments.