Duplex Stainless Steels E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 572

Veröffentlichungsjahr: 2013

Beschreibung

Duplex Stainless Steels (DSSs) are chromium-nickel-molybdenum-iron alloys that are usually in proportions optimized for equalizing the volume fractions of austenite and ferrite. Due to their ferritic-austenitic microstructure, they possess a higher mechanical strength and a better corrosion resistance than standard austenitic steels. This type of steel is now increasing its application and market field due to its very good properties and relatively low cost. This book is a review of the most recent progress achieved in the last 10 years on microstructure, corrosion resistance and mechanical strength properties, as well as applications, due to the development of new grades. Special attention will be given to fatigue and fracture behavior and to proposed models to account for mechanical behavior. Each subject will be developed in chapters written by experts recognized around the international industrial and scientific communities. The use of duplex stainless steels has grown rapidly in the last 10 years, particularly in the oil and gas industry, chemical tankers, pulp and paper as well as the chemical industry. In all these examples, topics like welding, corrosion resistance and mechanical strength properties (mainly in the fatigue domain) are crucial. Therefore, the update of welding and corrosion properties and the introduction of topics like texture effects, fatigue and fracture strength properties, and mechanical behavior modeling give this book specific focus and character.

Leseprobe

Table of Contents

Preface

Chapter 1: Process: Hot Workability

1.1. Introduction

1.2. As-cast microstructure

1.3. Microstructural evolution during hot working

1.4. Mechanical behavior under hot working

1.5. Static softening

1.6. Hot workability

1.7. Conclusions

1.8. Acknowledgments

1.9. References

Chapter 2: Corrosion Resistance Properties

2.1. Introduction

2.2. The duplex grades and pitting resistance equivalent numbers

2.3. Some fundamentals concerning stainless steel corrosion resistance

2.4. The different forms of corrosion

2.5. Some complex corrosion behaviors encountered in industrial applications

2.6. Conclusions

2.7. References

Chapter 3: Phase Transformation and Microstructure

3.1. Introduction

3.2. Phase diagrams and typical phases

3.3. Solidification

3.4. Austenite precipitation

3.5. Phase changes occurring below 1,000°C

3.6. Cold working and annealing

3.7. Final remarks

3.8. References

Chapter 4: Welding Processes, Microstructural Evolution and Final Properties of Duplex and Superduplex Stainless Steels

4.1. Introduction

4.2. δ-ferrite → austenite transformation

4.3. Secondary and intermetallic phases precipitation during welding processes

4.4. Welding processes for DSS and SDSS

4.5. Final remarks

4.6. References

Chapter 5: Thermal Embrittlement of Cast Duplex Stainless Steels: Observations and Modeling

5.1. Introduction

5.2. Composition, elaboration, microstructure, and mechanical properties

5.3. Thermal embrittlement of the ferrite phase in DSS

5.4. Materials investigated and embrittlement heat treatments

5.5. Damage and rupture

5.6. Scale effect and scatter

5.7. Modeling of rupture

5.8. Conclusion

5.9. References

Chapter 6: Low-Cycle Fatigue at Room Temperature

6.1. Introduction

6.2. Cyclic hardening/softening process

6.3. Uniaxial cyclic plasticity in DSSs

6.4. Final remarks

6.5. Acknowledgments

6.6. References

Chapter 7: Multiaxial Low-Cycle Fatigue Behavior at Room Temperature

7.1. Introduction

7.2. Multiaxial LCF – introduction

7.3. Biaxial LCF of a DSS type 25-07

7.4. Conclusions

7.5. Acknowledgments

7.6. References

Chapter 8: Partition of Cyclic Plasticity in the 25Cr-7Ni-0.25N Duplex Stainless Steel Investigated by Atomic Force Microscopy

8.1. Introduction

8.2. Material

8.3. Experimental procedure

8.4. Cyclic behavior at a low strain range

8.5. Cyclic behavior at a high strain range

8.6. Conclusions

8.7. References

Chapter 9: Macro- and Micromodeling of the Monotonic and Cyclic Mechanical Behavior of a Forged DSS

9.1. Introduction

9.2. Macroscopic modeling of the mechanical behavior

9.3. Micromechanical modeling

9.4. General conclusion

9.5. References

Chapter 10: Low-Cycle Fatigue at Intermediate Temperatures

10.1. Introduction

10.2. Materials studied

10.3. UNS S32900 DSS

10.4. UNS S32750 SDSS

10.5. Temperature influence on the fatigue life

10.6. Final remarks

10.7. Acknowledgments

10.8. References

Chapter 11: Industrial Processing and Fatigue Response of DSSs

11.1. Introduction

11.2. Morphological aspects

11.3. The role of morphological texture on the fatigue response

11.4. The role of nitrogen-content on the fatigue response of DSSs

11.5. Cyclic plasticity and fatigue of nitrogen-alloyed DSSs – effects of cyclic softening

11.6. Summary and conclusions

11.7. References

Chapter 12: Applications

12.1. Introduction

12.2. Historical review

12.3. Current (modern) DSS grades

12.4. Modern applications

12.5. Conclusions

12.6. References

Appendix

List of Authors

Index

First published in Great Britain and the United States in 2009 by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE LtdJohn Wiley & Sons, Inc.27-37 St George’s Road111 River StreetLondon SW19 4EUHoboken, NJ 07030UKUSAwww.iste.co.ukwww.wiley.com

© ISTE Ltd, 2009

The rights of Iris Alvarez-Armas and Suzanne Degallaix-Moreuil to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Duplex stainless steels / edited by Iris Alvarez-Armas, Suzanne Degallaix-Moreuil.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-84821-137-7

1. Duplex stainless steel. I. Alvarez-Armas, Iris. II. Degallaix-Moreuil, Suzanne.

TN757.C5D87 2009

672--dc22

2009026201

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN: 978-1-84821-137-7

Preface

Duplex stainless steels (DSSs) are chromium-nickel-molybdenum-iron bi-phased alloys in which the proportions of the constituent elements enable the optimization of the balance of the volume fractions of austenite and ferrite. Due to their ferritic-austenitic bi-phased microstructure, they possess higher mechanical strength and better corrosion resistance than standard austenitic stainless steels. Nowadays, the applications and markets for DSSs are increasing continuously, due to their outstanding properties and their relatively low cost.

The use of DSS has drastically grown in the last 10 years, particularly in the oil and gas, the pulp and paper, and chemical industries, and in chemical tankers. In all these examples, properties, such as welding, corrosion resistance, and mechanical strength, are crucial. Recent publications have also emphasized the importance of the fabrication process, as well as the effect of aging, on fracture and long-term mechanical properties, such as fatigue of DSSs; a subject that is hardly dealt with in Gunn’s1 book.

Since the edition of the book by Robert Gunn, there have been important advances in the knowledge of the DSSs, as revealed by the extensive research in the scientific literature on a wide range of topics relating to DSSs. The significance of the DSSs is reflected by the fact that the International Conference DUPLEX 2007 is the fourth conference on the subject since the publication of Gunn’s book, in a series of seven since the first St Louis, USA, in 1982.

The intention of the present book is to review the most updated progress achieved in the last 10 years regarding the microstructure, corrosion resistance, and mechanical strength properties of DSSs, as well as highlighting the industrial applications as a result of the development of new grades. The different subjects are developed in chapters written by world-renowned experts among the industrial and scientific communities:

Chapter 1 analyzes the impact of different microstructural variables on the hot workability of DSSs.

Chapter 2 focuses on corrosion-resistance properties and in-service properties of standard and newly developed duplex grades.

Chapter 3 describes the phase transformations that take place from the liquid state down to subzero temperatures, related microstructures, and their influence on mechanical and corrosion properties.

Chapter 4 analyzes the effect of thermal histories induced by welding processes on the austenitic-ferritic microstructure, as well as the secondary-phase precipitations. It is also proposed a guideline regarding the choice of material, process, and filler metal, in order to obtain sound welds, both in terms of corrosion resistance and mechanical properties.

Chapter 5 provides general information related to the elaboration of cast DSS and a review of the mechanisms of embrittlement occurring during aging in the temperature range 300-500°C and the consequences on fracture mechanical properties. Models of the heterogenity and size effects on the fracture result scatter are also provided.

Chapters 6 and 7 describe the cyclic plastic behavior and the dislocation structure evolution in DSSs tested under cyclic uniaxial (tension-compression) and multiaxial (tension-compression-torsion) cyclic loading at room temperature.

Chapter 8 discusses the cyclic accommodation mechanisms in a DSS from AFM measurements of the surface topography created in the two phases. It highlights the role played by each phase – austenite and ferrite – on the macroscopic behavior and provides an explanation of how they interact.

Chapter 9 discusses the modeling on different scales of monotonic and cyclic plastic behavior at room temperature observed in a hot-forged DSS.

Chapter 10 studies and compares the cyclic plastic behavior, the fatigue lifetimes, and the dislocation structures of different generations of DSSs in the as-received and aged conditions between 20 and 500°C.

Chapter 11 concisely summarizes the basics of the industrial production of DSSs and their effects on crystallographic and microstructural properties leading to differences in fatigue resistance.

Chapter 12 presents the large variety of application fields of different DSS grades and, in particular, the new DSSs.

Finally, an appendix summarizes the chemical composition of the different families of DSSs, including both cast and wrought austenitic and DSSs, and provides the designations from the different nomenclatural systems.

The Editors are grateful to all the authors who have kindly contributed to this book, especially for their effort and personal time invested in the writing of their contribution.

Iris ALVAREZ-ARMASSuzanne DEGALLAIX-MOREUIL

1 Gunn R.N., Ed., Duplex Stainless Steels, Microstructure, Properties and Applications, Abington publishing, Cambridge, 1997.