| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a repeatedly usable long nozzle for continuous casting which restrains the elution of carbon content into molten steel, is excellent in anti-spalling characteristics and corrosion resistance, and diminishes the occurrence of trouble caused by a break or crack, and also to reduce refractory costs and prevent the elution of carbon while restraining the interfusion of oxygen and slag into the molten steel by the use of the same. <P>SOLUTION: The invention relates to the long nozzle for continuous casting, of which part or all of the face at least exposed to the molten steel is made of a material layer 3 which is different from the material 2 of the nozzle body. The material layer 3 or an intermediate material layer is a refractory which has a carbon content of 10 mass% or less and contains one or more of alkaline metal oxides, alkaline earth metal oxides (except MgO) and boron compounds, in the total amount of 0.5 mass% or more and less than 30 mass%, with the balance being refractory aggregate. The refractory has an apparent porosity of 18% or more and 35% or less, and a ratio of B to A (B/A) controlled to 80% or lower where A denotes the flexural strength of the refractory at ordinary temperatures and B denotes the flexural strength of the refractory at 600°C or higher temperatures. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
