Skip to Main content Skip to Navigation
Conference papers

Modelling of Columnar-to-Equiaxed and Equiaxed-to- Columnar Transitions in Ingots Using a Multiphase Model

Abstract : We present a new method to handle a representative elementary volume (REV) with a mixture of columnar and equiaxed grains in ingot castings in the framework of an Eulerian volume averaged model. The multiscale model is based on a previously established fully equiaxed model. It consists of a three-phase (extra-granular liquid, intra-granular liquid and solid) grain-growth stage coupled with a two-phase (solid and liquid) macroscopic transport stage accounting for grain and nuclei movement. In this context, we take into account the formation of a columnar structure and its development using a simplified front-tracking method. Columnar solidification is coupled with the growth of equiaxed grains ahead of the columnar front. The particularity of the model is the treatment of concurrent growth of mixed columnar and equiaxed structures only in the volumes that contain the columnar front. Everywhere else, the structure is considered either fully columnar or fully equiaxed. This feature allows for reasonable computational times even in industrial size castings, while describing the solutal and mechanical blocking phenomena responsible for the Columnar-to-Equiaxed Transition. After a validation of the model, we discuss the numerical results for a 6.2-ton industrial steel ingot by comparison with experimental measurements. Final maps for macrosegregation and grain structures size and morphology are analysed. Furthermore, we quantify the impact of nuclei formation through fragmentation along the columnar front on the result. An attempt at predicting the occurrence of the Equiaxed-to-Columnar Transition in the later phases of the process is also made.
Complete list of metadata

Cited literature [13 references]  Display  Hide  Download
Contributor : Magalie Prudon Connect in order to contact the contributor
Submitted on : Tuesday, January 12, 2016 - 11:04:45 AM
Last modification on : Monday, December 13, 2021 - 1:52:03 PM
Long-term archiving on: : Thursday, November 10, 2016 - 11:42:38 PM


Publisher files allowed on an open archive



Nicolas Leriche, Hervé Combeau, Charles-André Gandin, Miha Zaloznik. Modelling of Columnar-to-Equiaxed and Equiaxed-to- Columnar Transitions in Ingots Using a Multiphase Model. MCWASP XIV: International Conference on Modelling of Casting, Welding and Advanced Solidification Processes, Jun 2015, Awaji island, Hyogo, Japan. pp.012087, ⟨10.1088/1757-899X/84/1/012087⟩. ⟨hal-01254330⟩



Record views


Files downloads