The existence of electro-capillary oscillation in alternate current eletroslag remelting was proved by theoretic analysis, dynamic simulation experiment and ESR experiment. The higher the frequency of alternate curren...The existence of electro-capillary oscillation in alternate current eletroslag remelting was proved by theoretic analysis, dynamic simulation experiment and ESR experiment. The higher the frequency of alternate current, the higher oscillation frequency of interface between slag pool and metal pool is, and the less amplitude is. Electro-capillary oscillation at the interface between slag pool and metal pool does not exist with direct current eletroslag remelting. The behaviors of desulphurizing, deoxidizing and removing inclusion were analyzed. The desulphurizing and the removing inclusion of steel in alternate current electroslag furnace are better than that in direct current electroslag furnace.展开更多
As the raw material for hot metal containing chromium from 20% to 40%, carbon-beared chromite pellets made from three kinds of typical chromite were reduced at 1 300 ℃ for 30 min and then kept at 1 550-1 600 ℃ for 1...As the raw material for hot metal containing chromium from 20% to 40%, carbon-beared chromite pellets made from three kinds of typical chromite were reduced at 1 300 ℃ for 30 min and then kept at 1 550-1 600 ℃ for 10 min. The effect of Cr 2O 3/FeO mass ratio in pellets on chromium content in hot metal and the yield of chromium were investigated. The results indicated that the highest chromium content is in hot metal produced from South African UG2 ore, but slag volume produced with Indian chromite is the smallest. The yield of chromium is only 60% to 75%, due to short melting time, high melting point and large surface tension of the slag with high Al 2O 3 and MgO content, which influences the separation between metal and slag.展开更多
The dynamic process of purifying emulsion using electromagnetic technique has been analyzed and studied by dynamics principle. Based on the results, the purification equipment has been developed and installed in a col...The dynamic process of purifying emulsion using electromagnetic technique has been analyzed and studied by dynamics principle. Based on the results, the purification equipment has been developed and installed in a cold rolling mill. The basic structure characteristics of the purification equipment were described in detail. Emulsion purified by this way can be recycled and used again with cost reduction.展开更多
The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the tempe...The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the temperature in the slag bath becomes more homogeneous, and therefore, the depth of molten metal pool is decreased; electrochemical reactions occur with the decrease in the frequency, and the atomic oxygen electrolyzed dissolves in the molten metal pool; the nonmetallic inclusions, which are distributed dispersively in the ingot, have an increased content, and their size is approximately in the range of 2--3 μm.展开更多
The thermodynamics of Mo-O- C and Ca-Mc-O-C systems was studied in order to understand the carbothermic reduction of molybdenum trioxide, and kinetic studies were also carried out by means of thermogravimetrie analysi...The thermodynamics of Mo-O- C and Ca-Mc-O-C systems was studied in order to understand the carbothermic reduction of molybdenum trioxide, and kinetic studies were also carried out by means of thermogravimetrie analysis under argon atmosphere with a heating rate of 10 ℃/min. Subsequently, reaction products at various temperatures were identified by X-ray diffraction （XRD） and the results confirmed the previous thermodynamics analysis. Mean- while, it was found that intermediate products MoO2 and CaMoO4 appeared in the process of carbothermic reduction of MoO3 with or without CaO, which were subsequently reduced to Mo or molybdenum carbide. An experimentally determined reaction mechanism was proposed and discussed. The reduction reaction of MoO3 with carbon could be divided into two stages. The first stage includes the direct reaction between MoO3 and carbon and the carbon gasifica- tion reaction. The second stage is the gas-solid reaction between CO and MoO2, and the diffusion of gases through the surface of MoO2 determines the overall reaction rate. The activation energies of the mixtures with or without CaO were estimated to be 56.6 and 52.9 kJ/mol, respectively.展开更多
基金Project Sponsored by National Natural Science Foundation(59674031)
文摘The existence of electro-capillary oscillation in alternate current eletroslag remelting was proved by theoretic analysis, dynamic simulation experiment and ESR experiment. The higher the frequency of alternate current, the higher oscillation frequency of interface between slag pool and metal pool is, and the less amplitude is. Electro-capillary oscillation at the interface between slag pool and metal pool does not exist with direct current eletroslag remelting. The behaviors of desulphurizing, deoxidizing and removing inclusion were analyzed. The desulphurizing and the removing inclusion of steel in alternate current electroslag furnace are better than that in direct current electroslag furnace.
文摘As the raw material for hot metal containing chromium from 20% to 40%, carbon-beared chromite pellets made from three kinds of typical chromite were reduced at 1 300 ℃ for 30 min and then kept at 1 550-1 600 ℃ for 10 min. The effect of Cr 2O 3/FeO mass ratio in pellets on chromium content in hot metal and the yield of chromium were investigated. The results indicated that the highest chromium content is in hot metal produced from South African UG2 ore, but slag volume produced with Indian chromite is the smallest. The yield of chromium is only 60% to 75%, due to short melting time, high melting point and large surface tension of the slag with high Al 2O 3 and MgO content, which influences the separation between metal and slag.
文摘The dynamic process of purifying emulsion using electromagnetic technique has been analyzed and studied by dynamics principle. Based on the results, the purification equipment has been developed and installed in a cold rolling mill. The basic structure characteristics of the purification equipment were described in detail. Emulsion purified by this way can be recycled and used again with cost reduction.
文摘The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the temperature in the slag bath becomes more homogeneous, and therefore, the depth of molten metal pool is decreased; electrochemical reactions occur with the decrease in the frequency, and the atomic oxygen electrolyzed dissolves in the molten metal pool; the nonmetallic inclusions, which are distributed dispersively in the ingot, have an increased content, and their size is approximately in the range of 2--3 μm.
基金Item Sponsored by Science and Technology Achievement Special Foundation of Jiangsu Province of China(BA2010139)
文摘The thermodynamics of Mo-O- C and Ca-Mc-O-C systems was studied in order to understand the carbothermic reduction of molybdenum trioxide, and kinetic studies were also carried out by means of thermogravimetrie analysis under argon atmosphere with a heating rate of 10 ℃/min. Subsequently, reaction products at various temperatures were identified by X-ray diffraction （XRD） and the results confirmed the previous thermodynamics analysis. Mean- while, it was found that intermediate products MoO2 and CaMoO4 appeared in the process of carbothermic reduction of MoO3 with or without CaO, which were subsequently reduced to Mo or molybdenum carbide. An experimentally determined reaction mechanism was proposed and discussed. The reduction reaction of MoO3 with carbon could be divided into two stages. The first stage includes the direct reaction between MoO3 and carbon and the carbon gasifica- tion reaction. The second stage is the gas-solid reaction between CO and MoO2, and the diffusion of gases through the surface of MoO2 determines the overall reaction rate. The activation energies of the mixtures with or without CaO were estimated to be 56.6 and 52.9 kJ/mol, respectively.
