| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high zirconia cast refractory having a stable high electric resistance with less change in aging at a high temperature and a heat cycle stability with difficulty in being peeled off in raising a temperature. <P>SOLUTION: The high zirconia cast refractory whose property relating to the viscosity of a glass phase at a temperature of around 1,000°C and residual stress at the surface of the refractory are controlled contains ZrO<SB>2</SB>of 87-96 wt.%, Al<SB>2</SB>O<SB>3</SB>of ≥0.1 and <0.8 wt.%, SiO<SB>2</SB>of 3-10 wt.%, Na<SB>2</SB>O of <0.05 wt.%, K<SB>2</SB>O of 0.01-0.2 wt.%, B<SB>2</SB>O<SB>3</SB>of 0.1-1.0 wt.%, BaO of 0.1-0.5 wt.%, SrO of <0.05 wt.%, CaO of 0.01-0.15 wt.%, Y<SB>2</SB>O<SB>3</SB>of 0.05-0.4 wt.%, MgO of ≤0.1 wt.%, and Fe<SB>2</SB>O<SB>3</SB>and TiO<SB>2</SB>in total of ≤0.3 wt.%, but substantially does not contain P<SB>2</SB>O<SB>5</SB>and CuO. Its electric resistance after being kept at 1,500°C for 12 h is 200 Ωcm or above. <P>COPYRIGHT: (C)2008,JPO&INPIT |
