scholarly journals Forecasting the physical and chemical and thermophysical properties of nickel-containing ferroalloys

2018 ◽  
pp. 336-348
Author(s):  
A.F. Petrov ◽  
O.V. Kuksa ◽  
L.A. Golovko ◽  
N.E. Khodotova
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Interatomic Interaction ◽  
Model Parameters ◽  
Melting Points ◽  
National Academy Of Sciences ◽  
Iron And Steel ◽  
Nickel Chromium ◽  
Composition Structure

The aim of the work is to study the possibility of using integral and partial model parameters of interatomic interaction for the systematic study of the most important consumer properties of nickel ferroalloys used for alloying steel and alloys. In the work, a new approach developed at the Iron and Steel Institute of the National Academy of Sciences of Ukraine was used to solve the problems of predicting the properties of alloys, connecting the composition, structure and properties of melts. Using experimental data on the heat of melting, heat capacity, thermal conductivity, thermal diffusivity of ferronickel, ferroboron, ferromolybdenum, ferro-tungsten, ferrozirconium and other ferroalloys, equations were obtained which made it possible to estimate these properties in advance. Analysis of the experimental data showed that the density of liquid iron-nickel-chromium alloys and their melting points are closely related to the interatomic interaction parameters. Using the parameters of interatomic interaction and experimental data, equations were obtained to describe the dependence of the crystallization temperature, specific density, specific heat capacity, thermal conductivity of nickel-chromium-containing ferroalloys on the parameters of interatomic interaction. Using the above equations, model melting points and ferronickel densities (FN-5M) were estimated using model prediction. The developed semi-empirical models can be used to predict the properties of standard grades of ferroalloys both within a single grade and the entire range of ferroalloys. This allows you to evaluate the effectiveness of the use of ferroalloys at the main stages of steelmaking.

scholarly journals Optimisation of chemical composition of high-strength structural steels for achieving mechanical property requirements

2021 ◽  
Author(s):  
Oleksandr Babachenko ◽  
Hanna Kononenko ◽  
Iryna Snigura ◽  
Nataliya Togobytska
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Chemical Composition ◽  
High Strength ◽  
Interatomic Interaction ◽  
Structural Steels ◽  
Integral Model ◽  
Model Parameters ◽  
National Academy Of Sciences ◽  
Iron And Steel

In addition to thermomechanical treatment, one of the main factors affecting the mechanical properties of steel is the chemical composition. The chemical composition may vary for a special high-strength low-alloy steel to meet certain mechanical property requirements. This work presents an approach, based on the method of physical-chemical modelling developed at the Z.I. Nekrasov Iron and Steel Institute of the National Academy of Sciences of Ukraine, to optimise the chemical composition of high-strength structural steels. The principle of this method is to describe the chemical composition of a melt by a complex of integral model parameters of interatomic interaction, characterising the chemical and structural state of the melt. The experimental data were analysed to obtain the regression model for mechanical properties based on the parameters of interatomic interaction. Finally, a multi-criteria optimisation method was applied to obtain an optimal set of microalloying elements which ensure the required mechanical properties.

Forced Convection Heat Transfer of Nanofluids: A Review

2017 ◽  
Author(s):  
Aditya Kuchibhotla ◽  
Debjyoti Banerjee
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Specific Heat ◽  
Forced Convection ◽  
Convection Heat Transfer ◽  
Convection Heat

Stable homogeneous colloidal suspensions of nanoparticles in a liquid solvents are termed as nanofluids. In this review the results for the forced convection heat transfer of nanofluids are gleaned from the literature reports. This study attempts to evaluate the experimental data in the literature for the efficacy of employing nanofluids as heat transfer fluids (HTF) and for Thermal Energy Storage (TES). The efficacy of nanofluids for improving the performance of compact heat exchangers were also explored. In addition to thermal conductivity and specific heat capacity the rheological behavior of nanofluids also play a significant role for various applications. The material properties of nanofluids are highly sensitive to small variations in synthesis protocols. Hence the scope of this review encompassed various sub-topics including: synthesis protocols for nanofluids, materials characterization, thermo-physical properties (thermal conductivity, viscosity, specific heat capacity), pressure drop and heat transfer coefficients under forced convection conditions. The measured values of heat transfer coefficient of the nanofluids varies with testing configuration i.e. flow regime, boundary condition and geometry. Furthermore, a review of the reported results on the effects of particle concentration, size, temperature is presented in this study. A brief discussion on the pros and cons of various models in the literature is also performed — especially pertaining to the reports on the anomalous enhancement in heat transfer coefficient of nanofluids. Furthermore, the experimental data in the literature indicate that the enhancement observed in heat transfer coefficient is incongruous compared to the level of thermal conductivity enhancement obtained in these studies. Plausible explanations for this incongruous behavior is explored in this review. A brief discussion on the applicability of conventional single phase convection correlations based on Newtonian rheological models for predicting the heat transfer characteristics of the nanofluids is also explored in this review (especially considering that nanofluids often display non-Newtonian rheology). Validity of various correlations reported in the literature that were developed from experiments, is also explored in this review. These comparisons were performed as a function of various parameters, such as, for the same mass flow rate, Reynolds number, mass averaged velocity and pumping power.

scholarly journals The interrelation of the chemical composition and mechanical properties of constructional alloyed steels

2018 ◽  
pp. 328-335
Author(s):  
V.A. Lutsenko ◽  
E.V. Parusov ◽  
T.N. Golubenko ◽  
O.V. Lutsenko ◽  
O.V. Parusov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Chemical Composition ◽  
Relative Elongation ◽  
Interatomic Interaction ◽  
Alloying Elements ◽  
Structural Parameter ◽  
National Academy Of Sciences ◽  
Iron And Steel ◽  
European Standards

The aim of the work is to determine the content intervals of alloying elements in structural alloyed steels, which ensure the obtaining of mechanical properties and the conformity of rolled products to the requirements of European standards. The studies were conducted using a predictive model developed by the Iron and Steel Institute of the National Academy of Sciences of Ukraine, taking into account the full chemical composition of the steel. The regularities of changes in the interatomic interaction parameter on the number of alloying elements in the steel composition and its relationship with mechanical properties are revealed. The dependences of mechanical properties (tensile strength, relative elongation) on the chemical composition of steel are constructed through the physicochemical criterion – the average statistical distance between interacting atoms (structural parameter d). The interrelation between the chemical composition and mechanical properties of chrome-molybdenum structural steels has been established. It is shown that increasing the chromium content increases the tensile strength, and doping with molybdenum and vanadium increases the ductility of rolled products. It was determined that in order to guarantee compliance with the requirements of the ultimate strength (900-1100 MPa) and relative elongation (> 11%) for steel 31CrMoV9, the content of alloying elements should correspond to the following intervals: 2.42-2.62%Cr, 0.2-0, 23%Mo and 0.17-0.20%V. The results obtained make it possible to predict the mechanical properties of doped steel, depending on the actual chemical composition of the steel.

TWO-LEVEL TUNNELLING MODEL DESCRIPTION OF THERMAL CONDUCTIVITY FOR CuxSn1-x METALLIC GLASSES AT LOW TEMPERATURE

2003 ◽  
Vol 17 (11) ◽  
pp. 2259-2271
Author(s):  
G. M. BHUIYAN ◽  
MD. SHAHJAHAN ◽  
ISSAM ALI ◽  
S. M. MUJIBUR RAHMAN
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Low Temperature ◽  
Metallic Glasses ◽  
Model Description ◽  
Recent Experimental Data ◽  
Model Parameters ◽  
Scattering Mechanism ◽  
Fitting Procedure ◽  
Theoretical Results

The two level tunnelling model is applied to analyze recent experimental data on low temperature thermal conductivity of Cu x Sn 1-x metallic glasses. An extra scattering mechanism due to Rayleigh is introduced to describe three characteristic regions of conductivity. Model parameters are determined using least-squares fitting procedure. Results derived from the parameters allow one to predict several interesting low temperature properties of metallic glasses in particular the characteristic plateau of conductivity. Theoretical results are also compared and contrasted with those of other metallic and non-metallic systems, and both common and uncommon features that exist between them are discussed.

scholarly journals Prediction of melting time of complex ferroalloys by physical and chemical modeling

2019 ◽  
pp. 205-214
Author(s):  
A.F. Petrov ◽  
I.R. Snihura ◽  
L.A Golovko ◽  
N.A. Tsyupa
Keyword(s):  
Interatomic Interaction ◽  
Ferroalloy Production ◽  
Melting Time ◽  
National Academy Of Sciences ◽  
Chemical Modeling ◽  
Method Of Calculation ◽  
Metal Melts ◽  
Composition Structure ◽  
Complex Ferroalloys ◽  
New Generation

The purpose of this work is to implement a new approach to the description of the duration of melting (dissolution) of complex new generation ferroalloys during the deoxidation and doping of a metal melt. This approach is aimed at developing a methodology and criteria for the quantification and accounting of the micro-heterogeneity of multicomponent metal melts and their prediction on such important for steelmaking production characteristics as the melting time of ferroalloys, the description of the inter-mine interaction, which allows a deeper understanding of the process. deoxidation and refining of steel. In the work, the approach developed in the Institute of Ferrous Metallurgy of the National Academy of Sciences of Ukraine to solve problems of modeling of non-conformities that relate the composition, structure and properties of melts is used in the work. It is based on the original concept of physicochemical modeling of the processes of interatomic interaction in melts and solutions, developed by E.V. Prihodko. According to it, metal melts are considered as chemically unified systems. Changing their composition affects the complex of physicochemical properties due to changes in the parameters of their electronic structure. The method of calculation of criteria (∆Zy and d), characterizing the degree of difference between the electronic and structural state of the melt, as a chemically unified system, from the mechanical mixture of their initial components and the parameter was used to evaluate and account for the influence of the micron homogeneity of the structure of the metal melts of ferroalloy production. ρl, which takes into account the cluster spin in metal melts. Using these criteria and the available experimental data, analytical dependences were obtained to calculate the melting time of complex (ma-manganese, vanadium, niobium and boromatic) ferroalloys of the new generation. This will allow them to evaluate their effectiveness of application, which is associated with the highest assimilation of the main elements that affect

scholarly journals On Experimental Thermal Analysis of Solid Materials

2014 ◽  
Vol 14 (6) ◽  
pp. 317-322 ◽  
Author(s):  
Pavel Koštial ◽  
Ivo Špička ◽  
Zora Jančikova ◽  
Jan Valiček ◽  
Marta Harničarova ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Heat Capacity ◽  
Cooling Curve ◽  
Solid Materials ◽  
Experimental Conditions ◽  
Capacitance Model ◽  
Special Case

Abstract The paper is devoted to the presentation of a method for measurement of thermal conductivity k, specific heat capacity cp, and thermal diffusivity applying the lumped capacitance model (LCM) as a special case of Newton’s model of cooling. At the specific experimental conditions resulting from the theoretical analysis of the used model, we present a method for experimental determination of all three above mentioned thermal parameters for materials with different thermal transport properties. The input experimental data provide a cooling curve of the tested material. The evaluation of experimental data is realized by software, the fundamental features of which are presented here. The statistical analysis of experimental data was performed.

EXPERIMENTAL INVESTIGATION FOR THE SIMULTANEOUS ESTIMATION OF THE THERMAL CONDUCTIVITY AND SPECIFIC HEAT CAPACITY USING A TWO-WIRE METHOD

2004 ◽  
Vol 18 (10n11) ◽  
pp. 1489-1502 ◽  
Author(s):  
V. GIARETTO ◽  
M. F. TORCHIO
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Simultaneous Estimation ◽  
Hot Wire ◽  
Resistance Thermometer ◽  
Wire Method ◽  
Prototype Apparatus

A prototype apparatus that uses two platinum wires for the simultaneous estimation of the thermal conductivity and specific heat capacity of liquids is described. The first wire is used both as a hot wire and a resistance thermometer, while the second one is used as a resistance thermometer. The aim of the work was to experimentally verify the advantages of employing a second wire to improve the reliability of the estimation of the properties. Three different liquids: water, propylene glycol, and a mixture of these are considered. An analytical solution with a changing heat flux is adopted. The thermal conductivity and the specific heat capacity are simultaneously estimated with a nonlinear regression (Maximum Likelihood) of the experimental data, using two-wire measurements or only hot-wire measurements. A comparison between these two approaches is reported and discussed.

scholarly journals Physical properties of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD)

2019 ◽  
Author(s):  
Zachariah Baird ◽  
Artur Dahlberg ◽  
Petri Uusi-Kyyny ◽  
Nahla Osmanbegovic ◽  
Joanna Witos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Isothermal Compressibility ◽  
Catalytic Properties ◽  
Enthalpy Of Vaporization ◽  
Liquid Viscosity ◽  
Public Data ◽  
Melting Properties ◽  
Liquid Vapor

7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD) has useful catalytic properties and can form an ionic liquid when mixed with an acid. Despite its potential usefulness, no data on its thermodynamic and transport properties is currently available in the literature. Here we present the first reliable public data on the liquid vapor pressure (temperature from 318.23 K to 451.2 K and pressure from 11.1 Pa to 10 000 Pa), liquid compressed density (293.15 K to 473.15 K and 0.092 MPa to 15.788 MPa), liquid isobaric heat capacity (312.48 K to 391.50 K), melting properties, liquid thermal conductivity (299.0 K to 372.9 K), liquid refractive index (293.15 K to 343.15 K), liquid viscosity (290.79 K to 363.00 K), liquid–vapor enthalpy of vaporization (318.23 K to 451.2 K), liquid thermal expansion coefficient (293.15 K to 473.15 K), and liquid isothermal compressibility of mTBD (293.15 K to 473.15). The properties of mTBD were compared with those of other relevant compounds, including 1,5-diazabicyclo(4.3.0)non-5-ene (DBN), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 1,1,3,3‐tetramethylguanidine (TMG). We used the PC-SAFT equation of state to model the thermodynamic properties of mTBD, DBN, DBU, and TMG. The PC-SAFT parameters were optimized using experimental data.

Parameter Determination for Chloride and Tritium Transport in Undisturbed Lysimeters during Steady Flow

1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten
Keyword(s):  
Experimental Data ◽  
Unsaturated Flow ◽  
Transport Model ◽  
Time Moment ◽  
Breakthrough Curves ◽  
Coarse Sand ◽  
Retardation Factor ◽  
Parameter Determination ◽  
Model Parameters ◽  
Water Fraction

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.

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