Effect of CaO/ SiO2 ratio on viscosity and structure of slag

The objective of this work is experimental determination of temperature dependences of viscosity of the molten CaO – Al2O3 - SiO2 system and assessment of impact of CaO/SiO2 ratio on viscosity and structure of this system. Experimental measurements of viscosity were performed with use of the high-temperature viscometer Anton Paar FRS 1 600. Viscosity was measured in a rotational mode during heating at the rate of 3,3 °C/min in the temperature interval from 1 673 to 1 873 K. Viscosity in the molten oxide system is determined by the internal structure. Exact clarification of the change of structure of the oxide system caused by the increased content of CaO was performed by Fourier transform infrared spectroscopy

Effect of CaO/ SiO2 ratio on viscosity and structure of slag

The objective of this work is experimental determination of temperature dependences of viscosity of the molten CaO – Al2O3 - SiO2 system and assessment of impact of CaO/SiO2 ratio on viscosity and structure of this system. Experimental measurements of viscosity were performed with use of the high-temperature viscometer Anton Paar FRS 1 600. Viscosity was measured in a rotational mode during heating at the rate of 3,3 °C/min in the temperature interval from 1 673 to 1 873 K. Viscosity in the molten oxide system is determined by the internal structure. Exact clarification of the change of structure of the oxide system caused by the increased content of CaO was performed by Fourier transform infrared spectroscopy

Primjena visokotemperaturne DTA za mikrolegirane čelike

Paper deals with investigation of phase transitions temperatures for selected real grades of micro-alloyed steels. Temperatures of characteristic phase transitions were obtained using Setaram SETSYS 18TM. The DTA technique was selected for the study of micro-alloyed steels. Temperatures of phase transitions (liquidus, solidus etc.) were obtained. Influence of admixed and alloyed elements on shift of temperatures was investigated. Resulting data were compared with temperatures of phase transitions of Fe-C, Fe-Mn systems and with temperatures calculated according to relations published in available literature. Thermodynamic-kinetic solidification model IDS was used to calculate characteristic equilibrium temperatures of investigated systems.Članak se bavi studijom faznih transformacija odabranih mikrolegiranih čelika. Temperaturne karakteristike faznih transformacija su istraživane rabljenjem laboratorijskog sustava Setaram SETSYS-18TM. DTA tehnika je odabrana za studij mikrolegiranih čelika. Temperature faznih transformacija (likvidus, solidus itd.) su dobivene. Istraživan je utjecaj primjesa i legirajućih elemenata na promjene temperatura faznih transformacija. Dobiveni experimentalni rezultati su bili uspoređeni s temperaturama faznih transformacija sistema Fe-C, Fe-Mn a i s temperaturama izračunatih iz dostupne literature. Termodinamičkokinetički model skrućivanja IDS je rabljen za izračun karakterističnih ravnotežnih temperatura faznih transformacija istraživanih sustava

Comparison of measured and calculated thermophysical properties of nickel super-alloys

Three real grades of nickel super-alloys (IN 713LC, IN 738LC and IN 792-5A) were investigated and values of temperatures of phase transformations and latent heats of melting were obtained. All investigated quantities are very important for thermodynamic and kinetic modelling. Moreover, these data are also valuable for a lot of software used for technological processes modelling. Experimental values were obtained using Differential Thermal Analysis (DTA) measurements. Calculations were performed using Thermo-Calc 3.1 software with the use of three different databases (SSOL5, TTNI8 and TCNI6). Comparison and discussion of experimental and calculated data was performed

Termofizikalna i strukturalna studija IN 792-5A niklove superlegure

The presented paper deals with study of phase transformations temperatures of nickel based superalloy IN 792-5A with application of DTA – method and use of experimental laboratory system for simultaneous thermal analysis SETARAM Setsys 18TM. Samples taken from as-received state of superalloy were heated with controlled ramp rates (1, 5, 10 and 20 °C•min-1) and immediately after melting they were cooled with the same controlled ramp rate. The samples before and after DTA-analysis were also subjected to the phase analysis with use of scanning electron microscopy on the microprobe (JCXA 733) equipped with energy dispersive analyser EDAX (EDAM 3).Rad daje studiju temperature faznih transformacija niklove superslitine IN792-5A primjenom DTA metode te eksperimentalnog laboratorijskog sustava za simulaciju termalne analize SETARAM Setsys 18TM. Uzorci su uzeti iz početnog stanja legure i održavani definiranim brzinama (1, 5, 10 i 20 °C•min-1) i poslije ohlađeni kontroliranim brzinama. Uzorci su prije i poslije DTA analiza bili predmet fazne analize s primjenom skeninga elektronske mikroskopije (JCXA 733) dopunjeno s energi disperznom analizom EDAX (EDAM 3)

Determination of solidus and liquidus temperatures for S34MnV steel grade by thermal analysis and calculations

The paper is devoted to the comparison of the results in the frame of solidus and liquidus temperatures obtained by thermo analytical methods with the generally used empirically based formulas and thermo dynamical Computherm software. The series of thermal analysis measurements of high temperature phase transformations of real steel grade (S34MnV) under conditions of two analytical devices (Netzsch STA 449 F3 Jupiter; Setaram Multi High Temperature Calorimeter (MHTC)) were carried out. Two thermo analytical methods were used (DSC and Direct Thermal Analysis). The different weight of samples was used (2,6 g; 23 g). The liquidus and solidus temperatures for close to equilibrium conditions during heating (DSC: 1 °C/min; 2 °C/min) and during cooling (Direct Thermal Analysis: 1 °C/min) were determined and compared. Then, the discussion on the different values obtained by experiments and empirically based calculation is realised

Characterization of chemical heterogeneity of the welded joint of two steels by modelling of diffusion processes

The paper deals with original methodology for characterization of chemical heterogeneity of welded joint by measurement of concentration profiles of substitution elements in three straight lines in a plane perpendicular to the weld interface. Three concentration profiles were evaluated by modelling of diffusion based on solution of the 2nd Fick’s law. Primary goal of evaluation consists in characterization of chemical heterogeneity in the narrow area on both sides of the welded joint on the basis of their mutual position. Experimental data are optimised by original adaptation of the Levenberg-Marquardt’s algorithm of non-linear regression. The paper deals with diffusion of nickel in the welded joint of two different steels as an example of investigated elements

Effect of CaO/ SiO₂ ratio on viscosity and structure of slag

The objective of this work is experimental determination of temperature dependences of viscosity of the molten CaO – Al2O3 - SiO2 system and assessment of impact of CaO/SiO2 ratio on viscosity and structure of this system. Experimental measurements of viscosity were performed with use of the high-temperature viscometer Anton Paar FRS 1 600. Viscosity was measured in a rotational mode during heating at the rate of 3,3 °C/min in the temperature interval from 1 673 to 1 873 K. Viscosity in the molten oxide system is determined by the internal structure. Exact clarification of the change of structure of the oxide system caused by the increased content of CaO was performed by Fourier transform infrared spectroscopy