Welding Metallurgy and Weldability E-Book

John C. Lippold

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

Seitenzahl: 574

Veröffentlichungsjahr: 2014

Beschreibung

Describes the weldability aspects of structural materials used in a wide variety of engineering structures, including steels, stainless steels, Ni-base alloys, and Al-base alloys

Welding Metallurgy and Weldability describes weld failure mechanisms associated with either fabrication or service, and failure mechanisms related to microstructure of the weldment. Weldability issues are divided into fabrication and service related failures; early chapters address hot cracking, warm (solid-state) cracking, and cold cracking that occur during initial fabrication, or repair. Guidance on failure analysis is also provided, along with examples of SEM fractography that will aid in determining failure mechanisms. Welding Metallurgy and Weldability examines a number of weldability testing techniques that can be used to quantify susceptibility to various forms of weld cracking. 

• Describes the mechanisms of weldability along with methods to improve weldability
• Includes an introduction to weldability testing and techniques, including strain-to-fracture and Varestraint tests
• Chapters are illustrated with practical examples based on 30 plus years of experience in the field

Illustrating the weldability aspects of structural materials used in a wide variety of engineering structures, Welding Metallurgy and Weldability provides engineers and students with the information needed to understand the basic concepts of welding metallurgy and to interpret the failures in welded components. 

Leseprobe

CONTENTS

Cover

Title page

Copyright page

Dedication page

Preface

Author Biography

1 Introduction

1.1 Fabrication-Related Defects

1.2 Service-Related Defects

1.3 Defect Prevention and Control

References

2 Welding Metallurgy Principles

2.1 Introduction

2.2 Regions of a Fusion Weld

2.3 Fusion Zone

2.4 Unmixed Zone (UMZ)

2.5 Partially Melted Zone (PMZ)

2.6 Heat Affected Zone (HAZ)

2.7 Solid-State Welding

References

3 Hot Cracking

3.1 Introduction

3.2 Weld Solidification Cracking

3.3 Liquation Cracking

References

4 Solid-State Cracking

4.1 Introduction

4.2 Ductility-dip Cracking

4.3 Reheat Cracking

4.4 Strain-age Cracking

4.5 Lamellar Cracking

4.6 Copper Contamination Cracking

References

5 Hydrogen-Induced Cracking

5.1 Introduction

5.2 Hydrogen Embrittlement Theories

5.3 Factors That Influence HIC

5.4 Quantifying Susceptibility to HIC

5.5 Identifying HIC

5.6 Preventing HIC

References

6 Corrosion

6.1 Introduction

6.2 Forms of Corrosion

6.3 Corrosion Testing

References

7 Fracture and Fatigue

7.1 Introduction

7.2 Fracture

7.3 Quantifying Fracture Toughness

7.4 Fatigue

7.5 Quantifying Fatigue Behavior

7.6 Identifying Fatigue Cracking

7.7 Avoiding Fatigue Failures

References

8 Failure Analysis

8.1 Introduction

8.2 Fractography

8.3 An Engineer's Guide to Failure Analysis

References

9 Weldability Testing

9.1 Introduction

9.2 Types of Weldability Test Techniques

9.3 The Varestraint Test

9.4 The Cast Pin Tear Test

9.5 The Hot Ductility Test

9.6 The Strain-to-Fracture Test

9.7 Reheat Cracking Test

9.8 Implant Test for HAZ Hydrogen-induced cracking

9.9 Gapped Bead-on-Plate Test for Weld Metal HIC

9.10 Other Weldability Tests

References

Appendix A: Composition of selected steels

Appendix B: Nominal Composition of Stainless Steels

2.1 Filler metals for stainless steels

Appendix C: Composition of Nickel-Base Alloys

Appendix D: Etching Techniques

A4.1 Steels

A4.2 Stainless Steels

A4.3 Nickel-Base Alloys

A4.4 Fracture Surface Cleaning

References

Index

End User License Agreement

List of Tables

Chapter 01

Table 1.1 Fabrication-related defects

Table 1.2 Service-related defects

Chapter 02

Table 2.1 Systems reported to undergo constitutional liquation

Chapter 03

Table 3.1 Partition coefficient,

k

, and RPF and MPF for some Fe binary alloys

Table 3.2 Cracking susceptibility factor (CSF) relationships for steels

Table 3.3 SCTR data for stainless steels and Ni-base alloys

Table 3.4 Comparison of nonequilibrium solidification temperature range determined by Scheil–Gulliver and single sensor differential thermal analysis (SS DTA) with the SCTR measured by the Varestraint test

Table 3.5 Fraction eutectic present in aluminum binary alloy systems at the maximum of cracking shown in Figure 3.19

Chapter 04

Table 4.1 Ductility-dip cracking theories

Table 4.2 Steels susceptible to reheat cracking

Table 4.3 Empirical relationships for reheat cracking susceptibility based on composition

Table 4.4 Systems susceptible to liquid metal embrittlement

Table 4.5 Materials susceptible or resistant to copper-contamination cracking based on the spot Varestraint test

Chapter 05

Table 5.1 Relative ranking of HIC susceptibility according to microstructure

Table 5.2 Carbon equivalent formulae for steels

Table 5.3 Estimating the susceptibility index using the AWS method

Table 5.4 Determining minimum preheat and interpass temperature based on susceptibility index, restraint level, and plate thickness

Chapter 06

Table 6.1 General corrosion rates of metals and alloys

Table 6.2 Galvanic series for metals in seawater

Table 6.3 Effect of alloying and impurity elements on pitting corrosion of stainless steels

Table 6.4 Pitting resistance equivalent (PRE) values for stainless steels

Table 6.5 Materials and environments leading to stress corrosion cracking

Table 6.6 Immersion tests for evaluation of intergranular corrosion

Chapter 08

Table 8.1 Failure investigation checklist

Chapter 09

Table 9.1 Summary of weldability tests covered under ISO standards 17641 and 17642

Table 9.2 Solidification cracking temperature range (SCTR) values for several stainless steels and Ni-base alloys obtained using the Transvarestraint test

Table 9.3 Recommended variables and variable ranges for Transvarestraint testing of stainless steels and Ni-base alloys

Appendix D

Table A4.1 Chemical etchants for steels

Table A4.2 Chemical etchants for stainless steels

Table A4.3 Electrolytic etching techniques for stainless steels

Table A4.4 Staining techniques for stainless steels

Table A4.5 Macroetchants for Ni-base alloys

Table A4.6 Microetchants (swab or immerse) for Ni-base alloys

Table A4.7 Microetchants (electrolytic) for Ni-base alloys

List of Illustrations

Chapter 01

Figure 1.1 Henri Granjon, Institut de Soudure.

Figure 1.2 Trevor Gooch, The Welding Institute, 1992.

Figure 1.3 Warren F. “Doc” Savage, Rensselaer Polytechnic Institute, 1986.

Figure 1.4 Fukuhisa Matsuda, Osaka University, 1988 (W.A. “Bud” Baeslack III in the background).

Figure 1.5 Liberty ship failure.

Chapter 02

Figure 2.1 Block diagram for weld microstructure evolution and performance.

Figure 2.2 Early schematic of regions of a fusion weld

Figure 2.3 Regions of a fusion weld

Figure 2.4 Modern schematic showing regions of a fusion weld.

Figure 2.5 Schematic illustration of the determination of dilution in a heterogeneous weld.

Figure 2.6 Examples of different solidification paths in a simple eutectic system.

Figure 2.7 Various forms of heterogeneous nucleation associated with a molten weld pool

Figure 2.8 Schematic illustration of epitaxial nucleation.

Figure 2.9 Solidification modes that occur in metals.

Figure 2.10 Effect of temperature gradient in the liquid,

G

L

, and solidification growth rate,

R

, on solidification mode.

Figure 2.11 Effect of composition and solidification parameter on solidification mode

Figure 2.12 Constitutional supercooling theory according to Chalmers [7].

Figure 2.13 Simplified schematic of the constitutional supercooling theory for the case of

k

< 1.

Figure 2.14 Illustration of epitaxial nucleation and competitive growth

Figure 2.15 Examples of (a) epitaxial nucleation in austenitic stainless steel and (b) nonepitaxial nucleation of fcc weld metal (Monel) deposited on bcc base metal (Type 409 SS).

Figure 2.16 Illustration of the elliptical and teardrop-shaped weld pools

Figure 2.17 Surface tension-induced fluid flow

Figure 2.18 Effect of weld pool shape on the solidification parameters

G

L

and

R

and the macroscopic grain structure

Figure 2.19 Relationship between weld travel speed,

V

W

, and local solidification rate,

R

.

Figure 2.20 Change in solidification growth mode as a function of location in the weld

Figure 2.21 Examples of planar (a) and cellular dendritic (b) growth modes.

Figure 2.22 Equiaxed dendritic growth in the terminal crater of a weld in Alloy 690. (a) Metallographic cross section and (b) SEM micrograph

Figure 2.23 Schematic representation of the boundaries in single-phase weld metals.

Figure 2.24 Examples of boundaries in the fusion zone of a fully austenitic (fcc) stainless steel.

Figure 2.25 Solute profiles for macroscopic weld solidification showing the (a) initial transient, (b) steady state region, and (c) final transient.

Figure 2.26 Solute profiles during formation of a solidification grain boundary, assuming < 1.