Duplex Stainless Steels

Microstructure, Properties and Applications

R Gunn

• Publisher: Woodhead Publishing
• Year: 1997
• Print ISBN: 9781855733183
• eBook ISBN: 9781845698775
• Topic: Technology & Engineering
• Subtopic: Mining Engineering
• Index: Technology & Engineering

Two very successful conferences - in Glasgow and Beaune - were held on duplex stainless steels during the first half of the '90s. This book takes keynote papers from each, and develops and expands them to bring the topics right up to date. There is new material to cover grades, specifications and standards, and the book is fully cross-references and indexed.The first reference book to be published on the increasingly popular duplex stainless steels, it will be widely welcomed by metallurgists, design and materials engineers, oil and gas engineers and anyone involved in materials development and properties. - The first reference book on this relatively new engineering material - Based on keynote papers from major international contributors - Covers grades, standards and specifications

1

Developments, grades and specifications

1.1 Historical developments

Stainless steels were developed during the first decades of the twentieth century in the United Kingdom and Germany. The earliest grades were martensitic and ferritic Fe-Cr steels, but quite soon the austenitic Fe-Cr-Ni steels became the largest group. The growth of the austenitic alloys stemmed from their ease of production and fabrication, particularly welding. Minimum carbon levels were high (around 0.08%), due to the existing furnaces and refining techniques. This made the steels sensitive to grain boundary carbide precipitation during heat treatment and welding, and sensitive to intergranular corrosion attack.

A duplex alloy is defined as one that contains a two-phase structure and is more often a descriptor of an alloy where both phases are present in significant quantities. In the context of this book, the term duplex stainless steel covers ferritic/austenitic Fe-Cr-Ni alloys with between 30% and 70% ferrite. The first reference to such alloys appears in 1927, when Bain and Griffith¹ published data on ferritic:austenitic structures. Within the next few years, several foundries in France, Germany, Sweden and the USA explored such steels, initially in the cast form.

Possibly the first commercial product dates from 1929² when Avesta Jernverk produced a grade called 453E with approximate composition 25%Cr-5%Ni. Soon after in 1932 and 1933 a modified grade with 25%Cr-5%Ni-1%Mo (grade 453S) was marketed. Applications included coolers of the Brobeck type (plate and forgings), autoclaves ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Dedication
• Copyright page
• Preface
• Abbreviations and glossary
• 1: Developments, grades and specifications
• 2: Alloy design
• 3: Microstructure
• 4: Forming and machining
• 5: Physical and mechanical properties
• 6: Corrosion
• 7: Stress corrosion cracking
• 8: Welding metallurgy
• 9: Welding processes
• 10: Weldment properties
• 11: Non-destructive testing of welds
• 12: Applications
• 13: Service experience
• Appendix A: Nominal composition of stainless steels and Ni-base alloys
• Appendix B: Welding consumables for duplex and superduplex stainless steel grades
• Index