Melt flow, solidification structures, and defects in 316 L steel strips produced by vertical centrifugal casting

Abstract

Vertical centrifugal casting can significantly enhance the filling capability of molten metals, enabling the production of complex thin-walled castings at near-rapid cooling rates. In this study, the melt flow, solidification structures, and defects in 316 L steel cast strips with a geometry of 80 mm × 60 mm × 2.5 mm produced by vertical centrifugal casting were numerically and experimentally analyzed under different rotation speeds. With gradually increasing the rotation speed from 150 r/min to 900 r/min, the simulated results showed the shortest filling time and minimum porosity volume in the cast strip at a rotation speed of 600 r/min. Since a strong turbulent flow was generated by the rotation of the mold cavity during the filling process, experimental results showed that a “non-dendritic” structure was obtained in 316 L cast strip when centrifugal force was involved, whereas the typical dendritic structure was observed in the reference sample without rotation. Most areas of the cast strip exhibited one-dimensional cooling, but three-sided cooling appeared near the side of the cast strip. Moreover, the pores and cracks in the 316 L strips were detected by computed tomography scanning and analyzed with the corresponding numerical simulations. Results indicated the existence of an optimal rotational speed for producing cast strips with minimal casting defects. This study provides a better understanding of the filling and solidification processes of strips produced by vertical centrifugal casting.

Keywords

Vertical centrifugal casting / Numerical simulation / Melt flow / Solidification behavior

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Funding

National MCF Energy R&D Program of China(No. 2018YFE0306102); National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809(No. 51974184)