ZHANG Yang (1999-), male, Master candidate. E-mail: yangzhang9924@foxmail.com
Al2O3-C refractories are important for the continuous casting process. It is essential for safe and effective steel making processes to enhance the strength and oxidation resistance of Al2O3-C refractories. A compound MAB phase Cr2AlB2 has attracted recent attention due to its high fracture toughness, high damage tolerance and excellent oxidation resistance. In this work, a ternary layered compound Cr2AlB2 was introduced into the Al2O3-C refractories. The structural evolution of Cr2AlB2 in Al2O3-C refractories after treated at different temperatures and its effect on the comprehensive properties of Al2O3-C refractories were analyzed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that a gradual decomposition of Cr2AlB2 in Al2O3-C refractories generates a core-shell structure of CrB and Al2O3 covered with Al2O3, and catalyses the formation of carbon nanotubes and carbon fibers on the surface of the core-shell structure after thermal treatment at 800-1 200 ℃. Cr3C2 covered by BN structure is formed inside the core-shell structure after thermal treatment at 1 200-1 600 ℃. As a result, the densification of Al2O3-C refractories is facilitated, and the cold modulus of rupture and oxidation resistance is enhanced. The cold modulus of rupture after coking at 1 400-1 600 ℃ is increased by approximately 9%, and the oxide index after treated in air at 1 400 ℃ is reduced from 44% to 31%.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |