Ed Pickering B.A., M.Sci. (Cantab)
Fitzwilliam College


University of Cambridge
Materials Science and Metallurgy
Pembroke Street, Cambridge CB2 3QZ, U. K.
ejp57@cam.ac.uk
+44 1223 334495


Ed Pickering


Macrosegregation in Steel Ingots

Macrosegregation refers to chemical segregation over the length scales of whole castings, which may have dimensions of several metres. This variation in chemistry can jeopordise the structural integrity of castings used in critical applications, and is impossible to reverse using sensible heat treatments. Macrosegregation arises due to mass transport of species over large distances, but has its orgins in microsegregation: the partitioning of solute between the solid and liquid phases during the cooling of a melt. There are two mechanisms of mass transport which are particularly important in steel-ingot casting: the buoyancy-driven flow of enriched interdendritic liquid, and the sedimentation of solute-poor equiaxed grains.

Predicting macrosegregation is a formidable challenge. Even the most advanced macromodels today cannot be relied upon to deliver accurate quantitative results, and a sinlge simulation may takes weeks to run on a computer cluster. My research aims to use simple criterion, which are computationally inexpensive, to predict the likelihood of 'A' segregate formation in steel ingots. This will hopefully allow for rapid comparisons of different alloys and casting parameters.

My research is funded by Rolls-Royce Power Engineering plc and works closely with Sheffield Forgemasters International.

Other Interests

I continue to take an active interest in nickel-based superalloy research carried out at the Cambridge University Rolls-Royce UTC, where I undertook my final year research project.


Publications




PT Group Materials Algorithms Materials Science and Metallurgy