ZIRCONIA-CARBON-CONTAINING REFRACTORY AND IMMERSION NOZZLE FOR CONTINUOUSLY CASTING A STEEL AS WELL AS METHOD FOR MANUFACTURING A ZIRCONIA-CARBON-CONTAINING REFRACTORY AND METHOD FOR MANUFACTURING AN IMMERSION NOZZLE FOR CONTINUOUSLY CASTING A STEEL

摘要

PROBLEM TO BE SOLVED: To provide a zirconia-carbon-containing refractory exhibiting an excellent tolerability as an immersion nozzle for continuously casting a steel.SOLUTION: The provided zirconia-carbon-containing refractory comprises: within the refractory texture thereof, zirconia particles and a carbon matrix material; and at least 78 and no more than 90 mass% of ZrOand at least 5 and no more than 17 mass% of carbon. The zirconia particles comprise, in a case where the total weight of the zirconia particles is defined as 100 mass%, at least 97 mass% of particles having diameters of 75 μm or less and at least 40 mass% of particles having diameters of 45 μm or less. The carbon matrix material has a maximal length of 100 μm or less and an average length of 45 μm and is included within the refractory at a ratio of at least 2 and no more than 15 mass%. The refractory exhibits a strain magnitude fluctuation value confined within 20% in a test method for inducing the rupture of a sample provided by forming the refractory in the shape of a ring by homogeneously compressing the sample from the inner hole thereof.