Solubility of Titanium and Carbon in Molten Fe-Ti Alloys Saturated with Carbon

Abstract

SynopsisThe solubilities of titanium and carbon in Fe-Csat Ti alloys were determined at temperatures from 1300°C to 1500°C. Some of the already reported values of titanium solubility were determined by measuring the acid-soluble titanium dissolved in rapidly cooled samples which inevitably contain the particles of titanium carbide sedimented during cooling. The sedimentation of titanium carbide results in the djfficulty in determining the accurate solubility of titanium. In order to solve this difculty, methods were newly devised to measure the total titanium content in rapidly cooled samples.The results obtained are as follows;(1) The solubility of titanium at temperatures from 1300°C to 1500°C was expressed as, log [%Til = (-6 760/T)+3.965(2) By the use of the carbon solubility in iron with different concentrations of titanium, the temperature dependence of the interaction coefficient, eTi, at temperatures from 1350°C to 1500°C was determined as, eTi -(-221/T)-0.072 (3) The change of standard Gibbs free energy for the reaction, Ti + Csat = T(s) , was obtained as 4G° = -30 500+ 13.3T (cal/ mol).

Formation of Titanium Carbonitride from Hot Metal.

“…The activity coefficient of titanium was recently re-evaluated by Li and Fruehan. 15) The new value of f Ti in Fe-C sat -Ti system is given by ............ (8) At 1 773 K the activity coefficient of Ti is 0.03, slightly higher than 0.023 obtained by Morizane et al 6) but the temperature dependence differs considerably with that obtained by Sumito et al 12) Using Eqs. (6), (5), and (8) lation of K TiC , K TiN , and f Ti , respectively, the minimum Ti concentration was re-calculated using Eq.…”

“…In the crystal, the titanium and nitrogen contents are high whereas carbon content is much lower than that in the background iron. The activity of TiC in a Fe-C sat -0.37mass%Ti melt at 1 773 K is about 0.28 based on the data of Sumito et al 12) and Morizane et al 6) In the ideal solid solution of Ti(C,N) with a TiC ϭ0.28, the carbon content should be 5.5 mass% which is higher than the carbon content in the metal. However, the EDX mapping showed much lower carbon content in the crystal than that in the metal.…”

“…Since the activities of carbon and titanium carbide in reaction (3) are unity, the activity coefficient of titanium can be determined by measuring the solubility of titanium in the Fe-C sat -Ti melts. The solubility of titanium in carbon saturated iron was studied by Sumito et al 12) and recently by Morizane et al 6) From Morizane's result, the activity coefficient of Ti at 1 773 K was calculated to be 0.023 taking the free energy of reaction (3) as Eq. (6) The minimum titanium concentration required to form Ti(C,N) in Fe-C sat -Ti-N melts, predicted using Eq.…”

Characteristics of Calcium-Aluminate Slags and Pig Iron Produced from Smelting-Reduction of Low-Grade Bauxites

“…This is further enhanced due to the low solubility of titanium in Fe-C saturated -Ti system. [29] Ti þ C ¼ TiC DG Another mechanism for the formation of TiC particles can be the direct reaction of the dissolved carbon in the melt with TiO 2 in the slag at slag/metal interface, as in reaction [26].…”

Effects of Temperature, Refractory Composition and Mass Transfer Rate on Corrosion Rate of Al₂O₃–SiO₂ System Bricks into CaO–SiO₂–Al₂O₃–MgO Slag

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] To introduce some examples of research to date, the main objects of research were the reaction between steelmaking slag and MgO system refractories such as MgO-C brick ( (Received on October 4, 2016; accepted on December 6, 2016) The corrosion rate of Al 2 O 3 -SiO 2 system bricks, which are practical fired bricks, into CaO-SiO 2 -Al 2 O 3 -MgO slag was investigated, and the effects of temperature, refractory composition and mass transfer rate in slag on the corrosion rate of the bricks were discussed. As a result, the corrosion rate decreased as the alumina content in the brick increased.…”