Electromagnetic refining of aluminum alloys by the CREM process: Part I. Working principle and metallurgical results

In the first part of this paper, the working principle of a new electromagnetic continuous casting process is described. The main peculiarities of this process are (1) the presence in the sump of a strong electromagnetically driven forced convection, which promotes the production of a fine equiaxed structure, and (2) the fact that the thickness of the segregation zone tends toward zero. Local measurement methods are applied to the study of electromagnetic and hydrodynamic phe-nomena inside the sump of aluminum alloy billets. Further, the evolution of both the grain size and the thickness of the segregated surface layer with the electric power input is presented. In summary, this new technology presents the advantages of avoiding the addition of grain refiners and substantially reducing the scalping operation.