During the hot rolling process, oxides are formed on the surface of metal products. These oxides, which are commonly called scales, must be eliminated before other post-processing. Currently, chemical pickling is the ...During the hot rolling process, oxides are formed on the surface of metal products. These oxides, which are commonly called scales, must be eliminated before other post-processing. Currently, chemical pickling is the most widespread technology for descaling. However, chemical pickling depicts several drawbacks such as severe pollution, high cost, and unstable quality. Consequently, Baosteel initiated the Baosteel mechanical descaling （BMD） technology research in 2009. The BMD technology uses a water jet containing abrasive to eliminate the scales. The metal surface after BMD processing achieves an excellent surface quality with grade of Sa3.0 and satisfies the requirement of subsequent processes such as stamping, coating, and cold rolling. In this study, the development history, process feature, and industrial application of the BMD technology are presented. In addition, further development and prospects of the BMD technology are forecasted.展开更多
8YSZ material that has high electrical conductivity is widely used as electrolytes for solid oxide fuel cells (SOFCs). But its low strength and low fracture toughness hampered the development of SOFCs. In order to fin...8YSZ material that has high electrical conductivity is widely used as electrolytes for solid oxide fuel cells (SOFCs). But its low strength and low fracture toughness hampered the development of SOFCs. In order to find a best method to improve the capability of YSZ electrolyte, the effects of 3Y-TZP additive on the density, strength, conductivity and microstructure were studied by means of X-ray diffraction and Vicker′s hardness apparatus. The strength and conductivity of YSZ electrolyte doped with different amounts of 3Y-TZP were determined. It is shown that the samples sintered at 1450 ℃ for 2 h are the best in properties. When 3Y-TZP powders are added to the YSZ system, the results demonstrate that strength of the electrolyte increases remarkably, and the fracture toughness is improved. The electrical conductivity is lowered only slightly. The results display that the flexural strength and the fracture toughness of ceramics with 30wt.% TZP reach 300 MPa and 3.7 MPa·m1/2, respectively, and the conductivity at 1000 ℃ reaches 0.11 S·cm-1.展开更多
在粉体气力输送系统中,浓相输送具有载运能力大、气量消耗少、气流速度低、管道和设备磨损小等优点。宝钢湛江钢铁2座5050 m 3高炉设计采用先进的喷煤工艺及设备,通过分析研究浓相输送技术,调整优化喷吹操作控制参数,将浓相输送技术成...在粉体气力输送系统中,浓相输送具有载运能力大、气量消耗少、气流速度低、管道和设备磨损小等优点。宝钢湛江钢铁2座5050 m 3高炉设计采用先进的喷煤工艺及设备,通过分析研究浓相输送技术,调整优化喷吹操作控制参数,将浓相输送技术成功应用在湛江钢铁高炉高煤比生产实践中,喷煤量达到100 t/h,固气比提高至46.5~51.0 kg/kg,有效地支撑了两座高炉长期稳定喷煤180~200 kg/t的实绩,同时输送稳定,输送气量消耗显著下降,系统管道和设备磨损减轻。展开更多
文摘During the hot rolling process, oxides are formed on the surface of metal products. These oxides, which are commonly called scales, must be eliminated before other post-processing. Currently, chemical pickling is the most widespread technology for descaling. However, chemical pickling depicts several drawbacks such as severe pollution, high cost, and unstable quality. Consequently, Baosteel initiated the Baosteel mechanical descaling （BMD） technology research in 2009. The BMD technology uses a water jet containing abrasive to eliminate the scales. The metal surface after BMD processing achieves an excellent surface quality with grade of Sa3.0 and satisfies the requirement of subsequent processes such as stamping, coating, and cold rolling. In this study, the development history, process feature, and industrial application of the BMD technology are presented. In addition, further development and prospects of the BMD technology are forecasted.
文摘8YSZ material that has high electrical conductivity is widely used as electrolytes for solid oxide fuel cells (SOFCs). But its low strength and low fracture toughness hampered the development of SOFCs. In order to find a best method to improve the capability of YSZ electrolyte, the effects of 3Y-TZP additive on the density, strength, conductivity and microstructure were studied by means of X-ray diffraction and Vicker′s hardness apparatus. The strength and conductivity of YSZ electrolyte doped with different amounts of 3Y-TZP were determined. It is shown that the samples sintered at 1450 ℃ for 2 h are the best in properties. When 3Y-TZP powders are added to the YSZ system, the results demonstrate that strength of the electrolyte increases remarkably, and the fracture toughness is improved. The electrical conductivity is lowered only slightly. The results display that the flexural strength and the fracture toughness of ceramics with 30wt.% TZP reach 300 MPa and 3.7 MPa·m1/2, respectively, and the conductivity at 1000 ℃ reaches 0.11 S·cm-1.
