6727

6278

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1390

سيزده، 94ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

علي شفيعي، محمد حسن عباسي

علي رضا اعلائي

1/3/91

علي سعيدي، حسين ادريس

1396/10/06

كتابنامه

مواد

مهندسي مواد

ID6278

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

95Determining of Optimum Conditions of Stiring Molten Steel by InjectingAr in Ladle Furnace to Obtain Homogeneous Chemical Composition and Temperature Distribution Seyyed Mohammad Hafezinejad Manshadi mhafezi65@yahoo com February 2012 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiDr Ali Shafyei Assoc Prof Supervisor E mail shafyei@cc iut ac irDr Mohammad Hasan Abbasi Prof Supervisor E mail abbasi32@cc iut ac irDr Ali Reza Alaei Assist Prof Advisor E mail alaei45alireza@gmail comAbstractGas injection into melt contained in ladle through porous plug is a useful technique for homogenizingtemperature distribution and chemical composition of molten steel Performance of the gas injection processdepends on the gas flow rate porous plug location and alloy addition position In the present work the effectsof gas flow rate depth of melt position of tracer injection and slag layer on mixing time for a ladle withcapacity of 40 tones whose porous plug located in 0 63R was investigated Experiments were carried out bybottom injection of Ar gas into the water model and silicone oil was used as top slag layer Mixing time forpresence as well as absence of oil layer was investigated in different gas flow rates and various bath depthsfor tracer injection at slag eye and opposite slag eye position Moreover the effect of gas flow rate alloyaddition position and slag layer on the dissolution rate of alloying elements was investigated usingcylindrical specimen of benzoic acid According to the obtained results for oil absence condition when thetracer injected at slag eye the maximum mixing time occurred in minimum bath depth 30 cm for each gasflow rate Also the mixing time decreased from 86 6 to 61 8 s with increasing gas flow rate from 3 to 6 75L min For each gas flow rate the minimum mixing time occurred at the maximum bath depth 45 cm thusthe mixing time decreased from 77 6 to 56 2 s with increasing of the gas flow rate from 3 to 6 75 L min When the tracer was injected at slag eye and in the presence of oil layer with 0 1L thickness the mixing timewas increased 75 to 107 However in the absence of oil layer when the tracer was injected at opposite slageye position the maximum mixing time occurred at minimum bath depth 30 cm for each gas flow rate Also the mixing time decreased from 109 25 to 74 s when gas flow rate increased from 3 to 6 75 L min Foreach gas flow rate the minimum mixing time occurred at the maximum bath depth 45 cm thus the mixingtime decreased from 94 8 to 62 6 s with increasing of the gas flow rate from 3 to 6 75 L min The mixingtime increased from 80 to 100 when the tracer was injected at opposite slag eye position in the presence ofoil layer with 0 1L thickness An empirical correlation was suggested for the mixing time for each position oftracer injection The results of dissolution rate measurements of benzoic acid specimens indicated that thedissolution rate in plume is higher than in the case of opposite position of plume and the presence of oil layerwith0 1L thickness led to decrease of dissolution rate Finally according to the secondary steelmakingparameters in ladle furnace in Iran alloy steel company the optimum conditions were suggested forhomogenizing molten steel by injecting of Ar gas Keywords Mixing time Gas injection Gas stirred ladle Homogenizing molten steel Dissolusion of alloying elements Entrapment of Slag

علي شفيعي، محمد حسن عباسي

علي رضا اعلائي

علي سعيدي، حسين ادريس