| Popis: |
The corrosion resistance of submerged entry nozzle (SEN) materials were investigated for high-class steel manufacturing. Composite samples were fabricated by mixing ZrO2, Al2O3, MgO, mullite, spinel, and carbon. The raw materials were mixed with attrition milling, compacted in a uniaxial pressure of 200MPa and calcined at 1000 o C for 3 h in N2 atmosphere. The bulk density and apparent porosity of the calcined samples were measured by the liquid displacement method in water using Archimedes's principle. The corrosion resistance of the samples were measured by cup test with mold powder at 1550 o C for 2 h. The microstructure and elemental analysis of samples were observed by scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and X-ray diffraction pattern (XRD). The XRD result shows that the starting raw materials were crystalline phase. The microstructure of fabricated specimen was investigated before and after corrosion tests at 1000 o C and 1550 o C for 2h. ZrO2-C composite showed good resistance in the slag corrosion test. Among the composite oxide materials, ZrO2-Al2O3-C and ZrO2-MgO-C showed better resistance than ZrO2-C in the slag corrosion test. The diameter variation index of ZrO2-C refractory was 16.1 at 1000 o C for 2 h. The diameter variation index of the ZrO2-Al2O3-C refractory was larger than that of the ZrO2-C refractory at 1550 o C for 2 h. |
