Crystallization behaviors of new developed CaO–Al
2O
3 based mould fluxes with TiO
2 addition for casting of high-Al steels were investigated by using DTA techniques combined with SEM-EDS and XRD analysis. XRD and SEM analyzed on the crystallized samples showed that the sequence of crystal precipitation for TiO
2-free mould flux during cooling was MgO, and followed by Ca
12Al
14O
33 during cooling. The sequence of crystal formation for TiO
2-bearing mould fluxes during cooling is CaTiO
3 to MgO, and then Ca
12Al
14O
33. Continuous cooling transformation diagrams (CCT) were constructed for analysis of the crystallization behaviors. The Undercooling values for onset crystallization of various crystals were calculated by using liquidus temperature obtained by heating DTA and crystallization temperature of various crystals. The crystallization temperatures of CaO–Al
2O
3 based mould fluxes increased with increasing TiO
2 content. The undercooling values for onset crystallization of CaTiO
3 decreased with increasing TiO
2 content, which indicating that the crystallization of CaTiO
3 was enhanced with increasing TiO
2 content. The undercooling values for onset crystallizations of Ca
12Al
14O
33 and MgO only changed slightly with increasing TiO
2. This indicated that crystallizations of Ca
12Al
14O
33 and MgO crystals were only slightly influenced by TiO
2 addition. The overall crystallization of mould fluxes was enhanced with increasing TiO
2 content.
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