Description
Book SynopsisDuplex 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.
Table of ContentsPreface xiii
Chapter 1. Process: Hot Workability 1
Isabel GUTIERREZ and Amaia IZA-MENDIA
1.1. Introduction 1
1.2. As-cast microstructure 1
1.3. Microstructural evolution during hot working 4
1.4. Mechanical behavior under hot working 16
1.5. Static softening 28
1.6. Hot workability 31
1.7. Conclusions 39
1.8. Acknowledgments 39
1.9. References 39
Chapter 2. Corrosion Resistance Properties 47
Jacques CHARLES
2.1. Introduction 47
2.2. The duplex grades and pitting resistance equivalent numbers 48
2.3. Some fundamentals concerning stainless steel corrosion resistance 50
2.4. The different forms of corrosion 60
2.5. Some complex corrosion behaviors encountered in industrial applications 100
2.6. Conclusions 111
2.7. References 111
Chapter 3. Phase Transformation and Microstructure 115
Angelo Fernando PADILHA and Ronald Lesley PLAUT
3.1. Introduction 115
3.2. Phase diagrams and typical phases 117
3.3. Solidification 120
3.4. Austenite precipitation 121
3.5. Phase changes occurring below 1,000°C 123
3.6. Cold working and annealing 132
3.7. Final remarks 134
3.8. References 135
Chapter 4. Welding Processes, Microstructural Evolution and Final Properties of Duplex and Superduplex Stainless Steels 141
Franco BONOLLO, Alberto TIZIANI and Paolo FERRO
4.1. Introduction 141
4.2. ƒÏ-ferrite ƒÏƒnaustenite transformation 142
4.3. Secondary and intermetallic phases precipitation during welding processes 145
4.4. Welding processes for DSS and SDSS 147
4.5. Final remarks 155
4.6. References 155
Chapter 5. Thermal Embrittlement of Cast Duplex Stainless Steels: Observations and Modeling 161
Andre PINEAU and Jacques BESSON
5.1. Introduction 161
5.2. Composition, elaboration, microstructure, and mechanical properties 163
5.3. Thermal embrittlement of the ferrite phase in DSS 170
5.4. Materials investigated and embrittlement heat treatments 181
5.5. Damage and rupture 186
5.6. Scale effect and scatter 189
5.7. Modeling of rupture 192
5.8. Conclusion 201
5.9. References 201
Chapter 6. Low-Cycle Fatigue at Room Temperature 209
Iris ALVAREZ-ARMAS
6.1. Introduction 209
6.2. Cyclic hardening/softening process 210
6.3. Uniaxial cyclic plasticity in DSSs 219
6.4. Final remarks 236
6.5. Acknowledgments 237
6.6. References 237
Chapter 7. Multiaxial Low-Cycle Fatigue Behavior at Room Temperature 241
Suzanne DEGALLAIX-MOREUIL
7.1. Introduction 241
7.2. Multiaxial LCF – introduction 242
7.3. Biaxial LCF of a DSS type 25-07 248
7.4. Conclusions 270
7.5. Acknowledgments 270
7.6. References 270
Chapter 8. Partition of Cyclic Plasticity in the 25Cr-7Ni-0.25N Duplex Stainless Steel Investigated by Atomic Force Microscopy 275
Jean-Bernard VOGT, Daniel SALAZAR and Ingrid PRORIOL SERRE
8.1. Introduction 275
8.2. Material 277
8.3. Experimental procedure 278
8.4. Cyclic behavior at a low strain range 280
8.5. Cyclic behavior at a high strain range 289
8.6. Conclusions 300
8.7. References 300
Chapter 9. Macro- and Micromodeling of the Monotonic and Cyclic Mechanical Behavior of a Forged DSS 303
Veronique AUBIN and Pierre EVRARD
9.1. Introduction 303
9.2. Macroscopic modeling of the mechanical behavior 304
9.3. Micromechanical modeling 318
9.4. General conclusion 332
9.5. References 334
Chapter 10. Low-Cycle Fatigue at Intermediate Temperatures 339
Alberto F. ARMAS
10.1. Introduction 339
10.2. Materials studied 342
10.3. UNS S32900 DSS 345
10.4. UNS S32750 SDSS 352
10.5. Temperature influence on the fatigue life 361
10.6. Final remarks 363
10.7. Acknowledgments 364
10.8. References 364
Chapter 11. Industrial Processing and Fatigue Response of DSSs 367
Nuri AKDUT
11.1. Introduction 367
11.2. Morphological aspects 369
11.3. The role of morphological texture on the fatigue response 372
11.4. The role of nitrogen-content on the fatigue response of DSSs 375
11.5. Cyclic plasticity and fatigue of nitrogen-alloyed DSSs – effects of cyclic softening 383
11.6. Summary and conclusions 395
11.7. References 396
Chapter 12. Applications 403
Mats LILJAS and Fredrik SJOHOLM
12.1. Introduction 403
12.2. Historical review 404
12.3. Current (modern) DSS grades 408
12.4. Modern applications 409
12.5. Conclusions 422
12.6. References 422
Appendix 425
List of Authors 429
Index 433
