نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
This study aims to identify the key production bottlenecks in manufacturing a high-quality tundish nozzle comparable to an imported foreign part. By overcoming these bottlenecks, we strive to develop the technical expertise necessary to produce these nozzles domestically. The tundish nozzle was examined in three parts: the metallic holder, the refractory castable (nozzle seat), and the nozzle insert. Analysis using ICP, SEM-EDS, and XRD revealed that this holder is composed of over 99.5% iron, with a carbon content of 0.055% and no significant alloying elements. The primary phase is alpha iron (ferrite), with a small amount (less than 1%) of iron carbide (cementite). Analysis of the refractory castable and nozzle insert using XRD, XRF, and SEM-EDS indicated that these components contain alumina, mullite, silica, and spinel phases (in the refractory castable) and partially stabilized zirconia using 2-3% calcium oxide and magnesium oxide (in the nozzle insert). We believe that the refractory part consists of alumina, clay compounds (including kaolin and ball clay), zircon (zirconium silicate), and carbon, while the insert utilizes partially stabilized zirconia. The research indicates that the key bottleneck in producing the metal holder is the shaping process, which uses a dedicated mold. For the refractory part, the bottleneck lies in achieving a suitable formulation of raw materials to obtain the desired phase composition for optimal performance under operating conditions. The production of the zirconia nozzle insert is challenging due to its complex and hollow shape, which requires specialized techniques such as slip casting or isostatic pressing, rather than conventional powder pressing.
کلیدواژهها English