A high blast temperature is an effective measure that improves pulverized coal injection （PCI）and energy consumption,decreases the cost of blast furnaces （BF）. Apart from using technology such as the increased vau...A high blast temperature is an effective measure that improves pulverized coal injection （PCI）and energy consumption,decreases the cost of blast furnaces （BF）. Apart from using technology such as the increased vault temperature of the hot-blast stove, the increased temperature of the waste gas, the preheating of combustion air and gas, and fully closed mixed air valves, other measures, such as using an oxygen-enriched blast stove, burning high heating value converter gas, increasing the number of stove changes to reduce the time needed for stove blasts, were taken to increase the blast temperature of the 2 500 m3 BF in recent years. The blast temperature of the 2 500 m3 BF was continuously increased in these years. The monthly average temperature of the 2 500 m3 BF reached 1 158℃, with the highest blast temperature reaching 1 195 ℃ in 2006. This technique of increased blast temperatures has reached an advanced level in China.展开更多
For steam tubes used in thermal power plant,the inner and outer walls were operated in high-temperature steam and flue gas environments respectively.In this study,structure,microstructure and chemical composition of o...For steam tubes used in thermal power plant,the inner and outer walls were operated in high-temperature steam and flue gas environments respectively.In this study,structure,microstructure and chemical composition of oxide films on inner and outer walls of exservice low Cr ferritic steel G102 tube and exservice high Cr ferritic steel T91 tube were analyzed.The oxide film was composed of outer oxide layer,inner oxide layer and internal oxidation zone.The outer oxide layer on the original surface of tube had a porous structure containing Fe oxides formed by diffusion and oxidation of Fe.More specially,the outer oxide layer formed in flue gas environment would mix with coal combustion products during the growth process.The inner oxide layer below the original surface of tube was made of Fe–Cr spinel.The internal oxidation zone was believed to be the precursor stage of inner oxide layer.The formation of internal oxidation zone was due to O diffusing along grain boundaries to form oxide.There were Fe–Cr–Si oxides discontinuously distributed along grain boundaries in the internal oxidation zone of G102,while there were Fe–Cr oxides continuously distributed along grain boundaries in that of T91.展开更多
文摘A high blast temperature is an effective measure that improves pulverized coal injection （PCI）and energy consumption,decreases the cost of blast furnaces （BF）. Apart from using technology such as the increased vault temperature of the hot-blast stove, the increased temperature of the waste gas, the preheating of combustion air and gas, and fully closed mixed air valves, other measures, such as using an oxygen-enriched blast stove, burning high heating value converter gas, increasing the number of stove changes to reduce the time needed for stove blasts, were taken to increase the blast temperature of the 2 500 m3 BF in recent years. The blast temperature of the 2 500 m3 BF was continuously increased in these years. The monthly average temperature of the 2 500 m3 BF reached 1 158℃, with the highest blast temperature reaching 1 195 ℃ in 2006. This technique of increased blast temperatures has reached an advanced level in China.
基金supported by the National Natural Science Foundation of China (Nos.51901113 and 51775300)the State Key Laboratory of Tribology in Tsinghua University, and the State Key Lab of Advanced Welding and Joining in Harbin Institute of Technology (No.AWJ-21M03)。
文摘For steam tubes used in thermal power plant,the inner and outer walls were operated in high-temperature steam and flue gas environments respectively.In this study,structure,microstructure and chemical composition of oxide films on inner and outer walls of exservice low Cr ferritic steel G102 tube and exservice high Cr ferritic steel T91 tube were analyzed.The oxide film was composed of outer oxide layer,inner oxide layer and internal oxidation zone.The outer oxide layer on the original surface of tube had a porous structure containing Fe oxides formed by diffusion and oxidation of Fe.More specially,the outer oxide layer formed in flue gas environment would mix with coal combustion products during the growth process.The inner oxide layer below the original surface of tube was made of Fe–Cr spinel.The internal oxidation zone was believed to be the precursor stage of inner oxide layer.The formation of internal oxidation zone was due to O diffusing along grain boundaries to form oxide.There were Fe–Cr–Si oxides discontinuously distributed along grain boundaries in the internal oxidation zone of G102,while there were Fe–Cr oxides continuously distributed along grain boundaries in that of T91.
