Reconstruction of Three‐Dimensional Dendritic Structures based on the Investigation of Microsegregation Patterns

The shape of growing dendrites during the solidification of cast steel depends on many different parameters. This includes the casting technique, the applied cooling conditions or the casting geometry. Alloying elements such as carbon, silicon or manganese have a major influence on the solidification behaviour and therefore on the morphology of the growing dendrites. In this paper, a method is presented which enables the reconstruction of three‐dimensional dendritic structures by using concentration maps of a certain alloying element. For this purpose, a sample of a conventionally produced St52 continuous casting steel has been investigated. To determine the required two‐dimensional maps, an electron probe microanalyzer (EPMA or “microprobe”) with wavelength dispersive spectrometers (WDS) has been used. After the EPMA measurements, a commercial software tool has been utilized to process the concentration maps to three‐dimensional structures. This processing includes an iterative numerical method which allows estimating the curvature effect on the measured concentration patterns and therefore on the dendritic shape.