Study Of The Composition Carbon-Free Submerged Entry Nozzles For Continuous Casting Of Clean Steel

The probability of the using of spinel, corundum-spinel and corundum-mullite as carbon-free inside liner of Submerged Entry Nozzle has been studied from the sinterability and thermal expansion of materials in this work. The results were listed as follows:1) For the inside liner of spinel, with the increasing of the content of active a -Al2O3, the samples are easier to sinter and the coefficients of thermal expansion also become smaller. The samples containing 1% SiO2 or 1% Si additives have good sinterability and their coefficients of thermal expansion also are decreased.2) For the inside liner of corundum-spinel, with the increasing of the content of active a -Al2O3, the samples are easier to sinter. TiO2 and Si can improve the sintering of corundum and decrease their coefficients of thermal expansion.3) For the inside liner of mullite, with the increasing of the content of Uf-AS, the samples are easier to sinter at 800 C and 1000 C. However too much Uf-AS is unfavorable to the intensity of the samples at 1500 C, because Uf-AS can make much mullite which can produce huge expansion and destroy the structure of samples.4) For the matching between carbon-free material and aluminum-carbon material, the spinel with 1 % SiO2 and 2% MgO can match very well with aluminum-carbon material, and there are no flaws in the inside liner and outer material.