The SGTE Casebook

Thermodynamics at Work

K Hack

• Publisher: Woodhead Publishing
• Year: 2008
• Print ISBN:
  9781845692155
• Edition: 2
• eBook ISBN:
  9781845693954
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

The Scientific Group Thermodata Europe (SGTE) is a consortium of European and North American research groups developing thermodynamic databases and software to model the thermodynamic properties of metals and other materials. Understanding these properties is critical to improving the processing of metals and their performance in such areas as resistance to high-temperature corrosion.This substantially revised new edition explores both the theoretical background to thermodynamic modelling and its wide range of practical applications. These applications include the analysis of hot salt and other types of high-temperature corrosion, understanding the loss of corrosion resistance in stainless and other types of steel, the processing of steels, as well as the use of thermodynamics to improve the functionality of materials for microelectronics and lighting applications, and in the analysis of nuclear safety issues. New case studies also illustrate applications to kinetically-controlled processes such as the solidification and heat treatment of alloys as well as the production of silicon and titanium oxide pigment.The SGTE casebook is a valuable reference for those manufacturing steels and other materials, those using materials in high-temperature applications such as the power industry and in other areas such as microelectronics and lighting. - This updated and revised edition explores theoretical background to thermodynamic modelling - Practical applications are provided, including types of high-temperature corrosion - Valuable reference for the power and microelectronics industry

I.1

Basic thermochemical relationships

Klaus Hack

Publisher Summary

This chapter discusses the basic thermochemical relationships. Since the publication of Gibbs’ last paper in the series, “On the equilibrium of heterogeneous substances,” in 1878, all the terms necessary to describe chemical equilibrium have been defined. The chemical potential had been introduced and the relation governing the different types of phase diagram and the Gibbs–Duhem equation had been derived. Electrochemistry can only be treated if the electrical work term is explicitly included. The entire database derived under the conditions is a Gibbs energy, rather than a Helmholtz, enthalpy, or internal energy database. Problems with constant temperature and volume have to be treated in an indirect way, which is no problem for the computer. Using the Maxwell relations, one can easily derive a diagrammatic scheme to relate the Gibbs energy in its natural variables with the other state functions and their natural variables, such as the Helmholtz energy, the enthalpy, and the internal energy.

I.1.1 Introduction

Since the publication of Gibbs last paper [878Gib] in the series ‘On the equilibrium of heterogeneous substances’ in 1878, all terms necessary to describe (chemical) equilibrium are defined. The chemical potential had been introduced, and the relation governing the different types of phase diagram (the Gibbs–Duhem equation) had been derived. Furthermore the different work terms in what we now rightly call Gibbs fundamental equation had been discussed far beyond the contribution of chemical or electrical work and included already, e.g. the contribution of surface tension or the gravitational potential. Gibbs also stated clearly that it is only the relative magnitude of each of these terms that permits omission for practical purposes; in principle, all possible contributions are always present.

Most problems dealt with in equilibrium thermochemistry are those with constant temperature and pressure and where the other work terms, except for the chemical contribution, are usually omitted. Electrochemistry, of course, can only be treated if the electrical work term is also explicitly included. It is important to keep this in mind since the e...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributing authors
• Software packages used for the case studies
• Member organisations of SGTE
• Editor’s acknowledgements
• Dedication
• Foreword
• Introduction
• I.1: Basic thermochemical relationships
• I.2: Models and data
• I.3: Phase diagrams
• I.4: Summarising mathematical relationships between the Gibbs energy and other thermodynamic information
• II.1: Hot salt corrosion of superalloys
• II.2: Computer-assisted development of high-speed steels
• II.3: Using calculated phase diagrams in the selection of the composition of cemented WC tools with a Co–Fe–Ni binder phase
• II.4: Prediction of loss of corrosion resistance in austenitic stainless steels
• II.5: Prediction of a quasiternary section of a quaternary phase diagram
• II.6: Hot isostatic pressing of Al–Ni alloys
• II.7: Thermodynamics in microelectronics
• II.8: Calculation of the phase diagrams of the MgO–FeO–Al2O3–SiO2 system at high pressures and temperatures: application to the mineral structure of the Earth’s mantle transition zone
• II.9: Calculation of the concentration of iron and copper ions in aqueous sulphuric acid solutions as functions of the electrode potential
• II.10: Thermochemical conditions for the production of low-carbon stainless steels
• II.11: Interpretation of complex thermochemical phenomena in severe nuclear accidents using a thermodynamic approach
• II.12: Nuclide distribution between steelmaking phases upon melting of sealed radioactive sources hidden in scrap
• II.13: Pyrometallurgy of copper–nickel–iron sulphide ores: the calculation of the distribution of components between matte, slag, alloy and gas phases
• II.14: High-temperature corrosion of SiC in hydrogen-oxygen environments
• II.15: The carbon potential during the heat treatment of steel
• II.16: Preventing clogging in a continuous casting process
• II.17: Evaluation of the EMF from a potential phase diagram for a quaternary system
• II.18: Application of the phase rule to the equilibria in the system Ca–C–O
• II.19: Thermodynamic prediction of the risk of hot corrosion in gas turbines
• II.20: The potential use of thermodynamic calculations for the prediction of metastable phase ranges resulting from mechanical alloying
• II.21: Adiabatic and quasi-adiabatic transformations
• II.22: Inclusion cleanness in calcium-treated steel grades
• II.23: Heat balances and CP calculations
• II.24: The industrial glass-melting process
• II.25: Relevance of thermodynamic key data for the development of high-temperature gas discharge light sources
• II.26: The prediction of mercury vapour pressures above amalgams for use in fluorescent lamps
• II.27: Modelling cements in an aqueous environment at elevated temperatures
• III.1: Introduction
• III.2: The Gulliver–Scheil method for the calculation of solidification paths
• III.3: Diffusion in multicomponent phases
• III.4: Simulation of dynamic and steady-state processes
• III.5: Setting kinetic controls for complex equilibrium calculations
• IV.1: Calculation of solidification paths for multicomponent systems
• IV.2: Computational phase studies in commercial aluminium and magnesium alloys
• IV.3: Multicomponent diffusion in compound steel
• IV.4: Melting of a tool steel
• IV.5: Thermodynamic modelling of processes during hot corrosion of heat exchanger components
• IV.6: Microstructure of a five-component Ni-base superalloy: experiments and simulation
• IV.7: Production of metallurgical-grade silicon in an electric arc furnace
• IV.8: Non-equilibrium modelling for the LD converter
• IV.9: Modelling TiO2 production by explicit use of reaction kinetics
• Index