| The composition and structure of electroslag during Electroslag RemeltingProcess were measured by using XRF and XRD methods. The changes ofconductivity and viscosity of slags with smelting time were analyzed based on thediagram of isothermal conductivity and viscosity in the CaF2-CaO-Al2O3system.According to the composition of electroslag and the coexistence theory of slagstructure, equilibrium relationship between dissolved aluminium and oxygen in liquidsteel was established. The calculated result shows that：(1)Changes of contents of Al2O3, CaF2, CaO, SiO2and FeO with smelting timeduring Electroslag Remelting Process were analyzed by XRF. Some phases with highmelting temperature such as11CaO·7A12O3·CaF2,12CaO·7A12O3and CaSiO3wereconfirmed by XRD in solidified slag．(2)The slag resistance remained at about0.65cm when the temperature was1500°C. The change trends remained the same as trends of the CaO concentration.Theslag viscosity was about0.080Pa s.The trends remained the opposite as trends of theCaF2concentration, but the some as trends of the CaO concentration.(3)The activity of A12O3in slag was calculated using the molecular ioncoexistence model. Based on that，the equilibrium relationship between dissolvedaluminium and oxygen in liquid steel was calculated. The result shows that for thesteel of present experiment when the content of dissolved aluminium in the steel meltis in the range of0.0001%to1%, as dissolved aluminium increasing the content ofdissolved oxygen in the steel melt decreased firstly and then increased, dissolvedoxygen reaches the minimum when dissolved aluminium is0.25%.In addition, the effect of TiO2composition on the viscosity ofCaF2-CaO-Al2O3-SiO2-TiO2slag system at high temperature was discussed throughthe high temperature viscosity experiments. The results show that：(1)When TiO2slag content added from4%to7%, the viscosity decreased first,but when the temperature was below1470°C, slag viscosity increased with increasingTiO2. When TiO2content added from7%to10%, slag viscosity reduced withincreasing TiO2. When slag TiO2content added from10%to13%, the viscosity changed little. With increasing temperature, the viscosity of the slag samples ofdifferent TiO2contents were maintained drop rule. And at the same temperature,increasing TiO2content played a role in reducing the viscosity of the slag, but theeffect reduced with increasing TiO2.(2)By linear regression, the trends of activation energy changing with the TiO2content matched the CaF2-CaO-Al2O3-SiO2-TiO2slag viscosity measurement well.(3)By Comparing the experimental results with the model predictions，when theoptics of CaF2was0.43or0.67, the model prediction error is smaller than that theoptics of CaF2was1.2. But whatever the optics of CaF2was0.43,0.67or1.2, manydate significantly deviated from a straight line that the measured values is equal to thepredicted values. It indicated that many predicted and experimental results deviationwas large, the model used for this studyneed to be cautious. |
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