| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a stable slow cooling action immediately from the start of casting while maintaining the advantages of mold flux with high viscosity. <P>SOLUTION: Regarding the mold flux, in its chemical composition, in mass%: CaO/SiO<SB>2</SB>=1.05 to 1.60; Al<SB>2</SB>O<SB>3</SB>=3 to 22%; MgO=4 to 14%; the total concentration expressed by (Al<SB>2</SB>O<SB>3</SB>+MgO) is 12 to 27%; TiO<SB>2</SB>=4 to 13%; the concentration balance value expressed by (CaO/SiO<SB>2</SB>-0.8)×TiO<SB>2</SB>is 1.5 to 4.1; and the total concentration expressed by (K<SB>2</SB>O+Na<SB>2</SB>O+Li<SB>2</SB>O+F) is 3 to 7%. Its crystallization temperature is 1,190 to 1,290°C, and its viscosity at 1,300°C is 0.2 to 0.9 Pa s. When the melted mold flux is crystallized while being cooled, with perovskite crystallized/precipitated at first as the nuclei, melilite as the main crystals is crystallized/precipitated, and the reduction in the crystallization temperature upon cooling of the melted flux at a rate of 10°C/min to the crystallization temperature upon cooling of the melted flux at a rate of 2°C/min is≤30°C. According to this invention, a slab of high quality in which the involvement of mold flux is prevented, and which has no deformation and cracks caused by solidification shrinkage can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
