A novel granulation process that involved the use of a rotary multi-nozzles cup atomizer and water cooling was proposed for ferroalloy manufacturing.The effects of rotating speed and nozzle diameter on the properties ...A novel granulation process that involved the use of a rotary multi-nozzles cup atomizer and water cooling was proposed for ferroalloy manufacturing.The effects of rotating speed and nozzle diameter on the properties of FeSi75 alloy(containing 75 wt.%Si)granules were investigated.Results indicated that median granule diameter decreased as rotating speed in creased,and initially increased and then decreased as nozzle diameter in creased.The optimal conditi ons for the gra nulation of FeSi75 alloy were a rotating speed of 150 r/min and nozzle diameter of 10 or 12 mm.The phase composition,micromorphology,and elemental distribution of the FeSi75 alloy granules were also studied by X-ray diffraction,scanning electron microscopy,and energy-dispersive X-ray spectrometry.In order to provide guidance for the layout and water depth of the tank,the solidification behavior of ferrosilicon alloy droplet was numerically studied.A simplified model was established to elucidate the traveling trajectory and heat transfer of alloy droplet in air and cooling water during the atomization process.The solidification time of droplet with different thicknesses of solidification layer increased with the in crease in alloy droplet diameter.展开更多
Thermal analysis plays a key role in the online inspection of molten iron quality.Different solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements af...Thermal analysis plays a key role in the online inspection of molten iron quality.Different solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements affecting the solidification of molten iron.In this study,FeSi75 was added in one chamber of the dual-chamber sample cup,and the influences of FeSi75 additive on the characteristic values of thermal analysis curves and vermiculating rate were investigated.The results show that with the increase of FeSi75,the start temperature of austenite formation TALfirstly decreases and then increases,but the start temperature of eutectic growth TSEF,the lowest eutectic temperature TEU,temperature at maximum eutectic reaction rate TEM,and highest eutectic temperature TERkeep always an increase.The temperature at final solidification point TEShas little change.The FeSi75 additive has different influences on the vermiculating rate of molten iron with different vermiculation,and the vermiculating rate increases for lower vermiculation molten iron while decreases for higher one.According to the thermal analysis curves obtained by a dual-chamber sample cup with 0.30wt.%FeSi75 additive in one chamber,the vermiculating rate of molten iron can be evaluated by comparing the characteristic values of these curves.The time differenceΔtERcorresponding to the highest eutectic temperature TERhas a closer relationship with the vermiculating rate,and a parabolic regression curve between the time differenceΔtERand vermiculating rateηhas been obtained within the range of 65%to 95%,which is suitable for the qualified melt.展开更多
基金the National Natural Science Foundation of China(Grant No.2018YFC1900501)Graduate Scientific Research and Innovation Foundation of Chongqing(CYB19003).
文摘A novel granulation process that involved the use of a rotary multi-nozzles cup atomizer and water cooling was proposed for ferroalloy manufacturing.The effects of rotating speed and nozzle diameter on the properties of FeSi75 alloy(containing 75 wt.%Si)granules were investigated.Results indicated that median granule diameter decreased as rotating speed in creased,and initially increased and then decreased as nozzle diameter in creased.The optimal conditi ons for the gra nulation of FeSi75 alloy were a rotating speed of 150 r/min and nozzle diameter of 10 or 12 mm.The phase composition,micromorphology,and elemental distribution of the FeSi75 alloy granules were also studied by X-ray diffraction,scanning electron microscopy,and energy-dispersive X-ray spectrometry.In order to provide guidance for the layout and water depth of the tank,the solidification behavior of ferrosilicon alloy droplet was numerically studied.A simplified model was established to elucidate the traveling trajectory and heat transfer of alloy droplet in air and cooling water during the atomization process.The solidification time of droplet with different thicknesses of solidification layer increased with the in crease in alloy droplet diameter.
基金the financial support of the State Key Laboratory of Engine Reliability(skler-202105)。
文摘Thermal analysis plays a key role in the online inspection of molten iron quality.Different solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements affecting the solidification of molten iron.In this study,FeSi75 was added in one chamber of the dual-chamber sample cup,and the influences of FeSi75 additive on the characteristic values of thermal analysis curves and vermiculating rate were investigated.The results show that with the increase of FeSi75,the start temperature of austenite formation TALfirstly decreases and then increases,but the start temperature of eutectic growth TSEF,the lowest eutectic temperature TEU,temperature at maximum eutectic reaction rate TEM,and highest eutectic temperature TERkeep always an increase.The temperature at final solidification point TEShas little change.The FeSi75 additive has different influences on the vermiculating rate of molten iron with different vermiculation,and the vermiculating rate increases for lower vermiculation molten iron while decreases for higher one.According to the thermal analysis curves obtained by a dual-chamber sample cup with 0.30wt.%FeSi75 additive in one chamber,the vermiculating rate of molten iron can be evaluated by comparing the characteristic values of these curves.The time differenceΔtERcorresponding to the highest eutectic temperature TERhas a closer relationship with the vermiculating rate,and a parabolic regression curve between the time differenceΔtERand vermiculating rateηhas been obtained within the range of 65%to 95%,which is suitable for the qualified melt.
