CRYSTALLIZATION OF OXIDE INCLUSIONS AND T HEIR RHEOLOGY DURING HOT-ROLLING

To obtain endogenous oxide inclusions which are fully deformed during hot rolling, a precise control of their composition is necessary : usu ally amorphous phases with low melting temperature are aimed at. This can be achieved by appropriate deoxidation practice. Nevertheless, dur ing thermal treatment, the supercooled liquid oxide phases are likely to crystallize-and therefore their rheology drastically changes. Cryst allization rates of various oxide compositions in the system CaO-Al2O3 -SiO2 (+ MnO or MgO) have been investigated. Relative ability of the c ompositions investigated to form supercooled liquid was interpreted in terms of glass forming theories.