The Role of Active Elements in the Oxidation Behaviour of High Temperature Metals and Alloys

ISBN-13: 9789401070096 / Angielski / Miękka / 2011 / 374 str.

E. Lang

Opis

Metals and alloys rely for their application at high temperature on the formation and retention of oxide scales, which act as a barrier between the metallic substrate and the reactive species in the environment such as 0, S, N, C, Cl, etc. This protection concept requires that the oxide grows slowly, develops a dense, uniform layer, is well adherent, has sufficient ductility to accom modate plastic deformation of the substrate and is resistant to thermal cycling. For many years it has been known that small concentrations of certain "active elements" such as Y and the rare earths, as well as carbon and sulphur, can exercise a significant influence upon the oxidation corrosion behaviour of high temperature metals and alloys. An increasing number of experimental studies on this topic have been published recently. However no generally accepted understanding with regard to the detailed mechanisms and the way in which alloy composition and structure, temperature and environmental conditions, etc., are interacting has yet been achieved, although many - often controversial - theories and ideas have been presented. It therefore seemed to be an appropriate time to bring together a group of experts to review and evaluate the current state-of-the-art and to discuss various aspects of this important topic."

Spis treści

List of Contents.- Session 1: Introduction.- Keynote Paper: Principles of Growth and Adhesion of Oxide Scales.- Communication: Oxide Adhesion on Periodic Table Group 4 and 5 Metals.- Poster: Electrode Potential/Temperature Diagrams and Their Application to High Temperature Corrosion.- Keynote Paper: Active Elements in Oxidation and their Properties.- Session 2: Effects of Active Elements in Synthetic Oxides.- Keynote Paper: Effect of Active Elements on Diffusion Properties of Synthetic Oxides.- Keynote Paper: Effects of Impurities on Mechanical Properties of Oxides.- Session 3: Effect of Active Elements on Oxidation of Metals and Alloys.- Keynote Paper: Effect of Active Elements on the Oxidation Behaviour of Al2O3-Formers.- Keynote Paper: Effect of Active Elements on the Oxidation Behaviour of Cr2O3-Formers.- Communications: The Influence of Active Elements on the Stress- Relaxation in the Scale and Substrate on Aluminaforming Alloys.- The Influence of Fine Structure, Morphology and Composition of Alloy and Oxide on the Growth of Cr2O3- Scales.- Posters: The Effect of Yttria Dispersions on the Growth and Morphology of Chromia and Alumina Scales.- Improvements in the Adhesion and Protectiveness of Scales Formed on Iron-Chromium Steels by the Application of Boron-Compounds.- Effects of Ta and Y Additions on the Oxidation and Hot Corrosion Behaviour of a ?/?? Alloy.- Keynote Paper: Effect of Active Elements on Mechanical Properties of Scales.- Communication: Effect of Rare Earth Metals on the Oxidation Resistance and Creep Strength.- Keynote Paper: The Effects of Precious Metals on the Oxidation and Hot Corrosion of Coatings.- Session 4: Interaction of Sulphur and Carbon in Oxidation.- Keynote Paper: The Role of Sulphur in the Growth and Adhesion of Oxide Scales.- Poster: The Influence of Sulphur and its Interaction with Yttrium on the Composition, Growth and Adherence of Oxide Scales on Alumina-Forming Alloys.- Keynote Paper: The Role of Carbon on the Growth and Adhesion of Oxide Scales.- Communication: Effect of CeO2 Coatings and Interfacial Segregations of S and C on the Oxidation Behaviour of Fe-Cr Alloys in O2.- Posters: Preoxidation for Sulphidation Protection of Fe-Ni-Cr- Alloys.- Effects of Hydrogen Chloride and of Nitrogen in the Oxidation of Fe-20cr.- Session 5: Practical Implications and Outlook.- Keynote Papers: Applicability of Active Elements in Industrial Practice.- Appraisal Keynote: Future Trends ad Developments.