scholarly journals Thermodynamic calculation of phase equilibria in stainless steels

2012 ◽  
Vol 48 (3) ◽  
pp. 383-390 ◽  
Author(s):  
G. Klancnik ◽  
Steiner Petrovic ◽  
J. Medved
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Melting Behavior ◽  
Calphad Method ◽  
Thermodynamic Calculations ◽  
Thermodynamic Investigation ◽  
Good Agreement ◽  
Alloy Systems

In this paper two examples of thermodynamic investigation of stainless steels using both, experimental and modeling approach are described. The ferritic-austenitic duplex stainless steel and austenitic stainless steel were investigated using thermal analysis. The complex melting behavior was evident for both alloy systems. Experimentally obtained data were compared with the results of the thermodynamic calculations using the CALPHAD method. The equilibrium thermal events were also described by the calculated heat capacity. In spite of the complexity of both selected real alloy systems a relative good agreement was obtained between the thermodynamic calculations and experimental results.

scholarly journals Experimental Study of Phase Composition of B-Fe-Mn-V Alloys and Thermodynamic Calculations of Phase Equilibria in the B-Mn-V and B-Fe-Mn-V Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Viera Homolová ◽  
Ján Kepič ◽  
Adéla Zemanová ◽  
Ondřej Zobač
Keyword(s):  
Electron Microscopy ◽  
Experimental Study ◽  
Quaternary System ◽  
Experimental Methods ◽  
Calphad Method ◽  
Thermodynamic Calculations ◽  
Interstitial Element ◽  
X Ray ◽  
Scanning Electron ◽  
Good Agreement

Phase compositions of B-Fe-Mn-V alloys were studied by several experimental methods (DTA measurement, X-ray diffractions, and scanning electron microscopy). Besides the experimental study of the quaternary system, thermodynamic modelling of the ternary B-Mn-V system by the Calphad method and thermodynamic calculations for the quaternary B-Fe-Mn-V system were performed. Calculations for the quaternary system are based on the ternary subsystems (B-Mn-V, B-Fe-V, B-Fe-Mn, and Fe-Mn-V). Boron is modelled as an interstitial element in all solid solutions of vanadium, manganese, and iron. Very good agreement between experimental results and thermodynamic calculations was achieved. The created thermodynamic database is suitable for thermodynamic calculations of phase diagrams for all the ternary subsystems and also for the B-Fe-Mn-V quaternary system.

Energetics of Intra- and Inter-molecular Bonds in the Three Nitrophenols

1994 ◽  
Vol 47 (9) ◽  
pp. 1651 ◽  
Author(s):  
R Sabbah ◽  
M Gouali
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Bond ◽  
Heat Capacity ◽  
Differential Thermal Analysis ◽  
Relative Stability ◽  
Intermolecular Bond ◽  
Resonance Energies ◽  
Heat Capacity Measurements ◽  
Intramolecular Hydrogen ◽  
Good Agreement

A thermodynamic study of the three nitrophenol isomers (general formula C6H5NO3) was realized by combustion calorimetry of small amounts of substance (a few milligrams), sublimation calorimetry, differential thermal analysis and heat capacity measurements. The experimental enthalpies of combustion, sublimation and fusion of these compounds are as follows: ortho para -ΔcH�m(s,298.15K)/kJ mol-1 2871.0�1.3 2875.1�0.9 2868.5�1.0 ΔsubH�m(298.15K)/kJ mol-1 72.30�0.28 91.23�0.49 92.39�0.43 ΔfusHm/kJ mol-1 18.32�0.35 20.54�0.34 17.33�0.10 Ttriple point/K 318.40�0.01 370.51�0.01 387.26�0.05   The strength of the intramolecular hydrogen bond in the ortho isomer was estimated equal to 20.09 kJ mol-1. The relative stability of the three isomers is discussed, and the intermolecular bond enthalpies have been determined. The experimental resonance energies Eexp,conj are 168.7, 142.8 and 148.2 kJ mol-1 for ortho -, meta- and para-nitrophenol respectively, and are in good agreement with theoretical values. The experimental atomization enthalpies Δa,expH°m(298.15K) are 6742.5�1.9, 6719.5�1.7 and 6724.9�1.8 kJ mol-1 for ortho -, meta- and para-nitrophenol respectively.

Prediction and Measurement of Residual Stresses Arising From Quenching of Stainless Steels

2004 ◽  
Author(s):  
S. Hossain ◽  
C. E. Truman ◽  
D. J. Smith ◽  
M. R. Daymond
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Stainless Steels ◽  
Numerical Study ◽  
Hole Drilling ◽  
The Core ◽  
Residual Stress State ◽  
Surface Residual Stresses ◽  
Compressive Residual Stresses ◽  
Good Agreement

This paper presents results from an experimental and numerical study examining the creation of highly triaxial residual stresses in stainless steel. This was motivated by a need to model and understand creep in aged power plant. The residual stresses were introduced by rapid spray water quenching of heated solid stainless steel spheres and cylinders. Finite element (FE) simulations predicted high compressive residual stresses around the surface of the specimens and tensile residual stresses near the centre. Surface residual stresses were measured using the incremental centre-hole drilling (ICHD) technique. Neutron diffraction (ND) was used to measure the interior residual stresses. The measurements were in good agreement with FE predictions. The ND measurements confirmed that a highly triaxial residual stress state existed in the core of the specimens.

Étude thermodynamique des trois isomères de l'acide hydroxybenzoïque

1993 ◽  
Vol 71 (9) ◽  
pp. 1378-1383 ◽  
Author(s):  
Raphaël Sabbah ◽  
Thi Huy Duc Le
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Differential Thermal Analysis ◽  
Thermodynamic Study ◽  
Experimental Results ◽  
Ortho Isomer ◽  
Resonance Energies ◽  
Hydroxybenzoic Acids ◽  
Heat Capacity Measurements ◽  
Good Agreement

A thermodynamic study of the three hydroxybenzoic acids was carried out by combustion and sublimation calorimetry, heat capacity measurements, and differential thermal analysis. The experimental results (in kJ mol−1) are summarized as:[Formula: see text]From these experimental results, it was possible to determine for the three isomers (i) the resonance energies. From their comparison, the ortho isomer seems to be the most stable. This result is discussed using a structural consideration; (ii) the enthalpies of atomization. These values are in good agreement with that calculated using a contribution method.

Effects of Al-Mg alloy treatment on behavior and size of inclusions in SUH 409L stainless steel

2017 ◽  
Vol 115 (1) ◽  
pp. 111 ◽  
Author(s):  
Yang Liu ◽  
Nanfu Zong
Keyword(s):  
Stainless Steel ◽  
Molten Steel ◽  
Stainless Steels ◽  
Thermodynamic Calculations ◽  
Mg Alloy ◽  
Nucleation Process ◽  
Industrial Experiments ◽  
Different Types

Different types of steel were produced by different deoxidization processes to investigate effects of Al-Mg alloy treatment on the behavior and size of inclusions in stainless steels. Both industrial experiments and thermodynamic calculations were studied. Results showed that irregular and clustered Al2O3 inclusions are dominant in aluminum killed stainless steels. Using Al-Mg alloy treatment, size of Al2O3 inclusions could be reduced, irregular and clustered Al2O3 inclusions can be changed into the spherical MgO ⋅ Al2O3 inclusions. Changes in size and number of inclusions result from that Al-Mg alloy treatment could significantly affect the nucleation process of MgO ⋅ Al2O3 inclusions in molten steel. When the content of Mg is enough, larger inclusions can be reduced by the Al-Mg alloy treatment, and inclusions can keep fine.

scholarly journals DTA measurements in the ternary Ag-Au-Ga system

2020 ◽  
pp. 21-21
Author(s):  
Dominika Jendrzejczyk-Handzlik ◽  
Piotr Handzlik
Keyword(s):  
Experimental Data ◽  
Thermal Analysis ◽  
Phase Diagram ◽  
Differential Thermal Analysis ◽  
Phase Transformations ◽  
Cross Sections ◽  
Calphad Method ◽  
Experimental Results ◽  
Zero Rate ◽  
Good Agreement

In this work, the ternary Ag-Au-Ga system was studied experimentally by differential thermal analysis (DTA). Measurements were carried out along two chosen cross-sections determined by the ratio of mole fractions XAg/XGa=1:1 and XAu/XGa=1:1 by applying Pegasus 404 apparatus form Netzsch. Experiments were performed at three rates: 1 K min-1, 5 K min-1 and 10 K min-1. Next, the obtained experimental results were used to estimate the temperatures of liquidus by applying extrapolation to zero rate. Moreover, the temperatures of invariant reactions and other phase transformations were investigated from DTA measurements which were carried out with the rate 1 K min-1. Finally, the experimental results were compared with the isopleths obtained from prediction and calculation of the phase diagram which were done by using CALPHAD method. Experimental data obtained in this work are in good agreement with the results of calculation.

Calculations and Modeling of Material Constants in Hyperbolic-Sine Creep Model for 316 Stainless Steels

2013 ◽  
Vol 457-458 ◽  
pp. 185-190 ◽  
Author(s):  
Fu Qiang Yang ◽  
He Xue ◽  
Ling Yan Zhao ◽  
Jin Tian
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Creep Rate ◽  
Stainless Steels ◽  
Creep Model ◽  
Material Constants ◽  
316 Stainless Steel ◽  
Hyperbolic Sine ◽  
Predict Model ◽  
Good Agreement

The material constants calculation models for hyperbolic-sine creep model were proposed. The material constants used in hyperbolic-sine creep model for 316 stainless steel were calculated due to the models proposed and experimental data in the temperature range from 873K to 1023K. The relationships between material constants of 316 stainless steel creep model and temperature were obtained by curve fitting. The creep rate predict model of 316 stainless steel with only stress and temperature was also developed, the creep rates predicted were in good agreement with experimental data.

NiAl precipitation in Fe-12w/o Cr-5w/o Ni-4w/o Al

1983 ◽  
Vol 41 ◽  
pp. 202-203
Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Alloy Composition ◽  
Chromium Content ◽  
Scale Up ◽  
Optical Metallography ◽  
Property Evaluation ◽  
310 Stainless Steel ◽  
Microstructural Studies

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.

BRILLIANT 2101 T-1 AP

Alloy Digest ◽  
2012 ◽  
Vol 61 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Good Balance ◽  
Steel Wires

Abstract Stoody AP stainless steel wires are all-position wires. The nickel in this product will achieve a good balance of austenite and ferrite in lean duplex stainless steels. This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SS-1118. Producer or source: Stoody Company.

AISI No. 633

Alloy Digest ◽  
1981 ◽  
Vol 30 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steels ◽  
High Strength ◽  
Heat Treating ◽  
Corrosion Resistant ◽  
Martensitic Stainless Steels ◽  
Steel Mills ◽  
Temperature Performance ◽  
Structural Applications

Abstract AISI No. 633 is a chromium-nickel-molybdenum stainless steel whose properties can be changed by heat treatment. It bridges the gap between the austenitic and martensitic stainless steels; that is, it has some of the properties of each. Its uses include high-strength structural applications, corrosion-resistant springs and knife blades. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-389. Producer or source: Stainless steel mills.

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