Influence of Residual Temperature on Microstructure Evaluation of Cast-Rolled 6061 Sheet

In this paper, a rolling process at residual temperatures is proposed. Special attention is given to the effects of different process parameters (e.g., residual rolling temperature and residual strain rate) on the microstructural evolution of cast-rolled 6061 aluminum alloy sheet. It was found that excellent grain refinement and a uniform structure (i.e., an average shrinkage cavity size of 13.71 μm and minimal grain size) were achieved at a residual rolling temperature of 390 ℃. With increasing rolling reduction, the grains in the core became more refined, and the grain size difference between the surface and central layers was reduced . Furthermore, the α(AlFeSi) phase was fragmented and dispersed with increasing pressure.