Practical Guide to Welding Solutions

Robert W. Messler, Jr., Ph.D., FASM, FAWS, is Emeritus Professor of Materials Science & Engineering at Rensselaer Polytechnic Institute, Troy, NY. His career spans more than four decades in diverse areas of advanced materials and processes in public and private industry and in academia, with unparalleled expertise in all aspects of joining. This "engineer who teaches" has authored more than a hundred technical papers and seven other engineering books. A Practical Guide to Welding Solutions being the logical complement to his renowned Principles of Welding, also by Wiley.

• Preface xi1 Introduction 1Further Reading 62 Categorization of Welding and Weld Problems 72.1 What Is Welding? 72.2 Microstructural Zones of Welds 132.3 Origin of Problems in Welding and Welds 192.4 How Problems Can Be Logically Categorized? 20References 21Further Reading 21Part I Manifestation of Problems with Welds and Weldments 233 Problems with Joint Setup and Weld Joints 253.1 Joint Efficiency 253.2 Weld Joint Types and Weld Configurations 263.3 Joint Setup Problems 313.4 Problems with Weld Profile 353.5 Troubleshooting Guide 42References 45Further Reading 454 Shape Distortion, Dimensional Shrinkage, and Geometric Instability 474.1 Thermal Versus Mechanical Stresses in a Structure 474.2 Residual Stresses Versus Distortion 484.3 Origin and Effect of Volumetric Shrinkage 484.4 Origin and Effect of Thermal Contraction 524.5 Problems from Nonuniform Thermal Contraction and CTE Mismatches 574.6 Problems from Distortion and from Residual Stresses 604.7 Distortion Control and Residual Stress Reduction 604.8 Troubleshooting Guide 65References 65Further Reading 665 Porosity 675.1 The Most Common Problem in Welds 675.2 Types of Weld Porosity 705.3 Gases in Molten Weld Metal 735.4 The Many Possible Causes of Porosity in Welds 795.5 Attempting to Minimize Porosity Formation in Fusion Welds 845.6 Troubleshooting Porosity Problems in Welds 85References 87Further Reading 876 Cracks 896.1 The Most Dreaded Defect in Welds 896.2 Classification of Cracking and Cracks in Welds and Welding 906.3 Hot Cracking and Cracks 916.4 Cold Cracking and Cracks 986.5 Other Weld-Related Cracking and Cracks 1016.6 Crack-Prone Metals and Alloys 1026.7 Troubleshooting Cracking Problems in Welds 105References 106Further Reading 1077 Nonmetallic and Metallic Inclusions 1097.1 Solid Versus Gas Inclusions 1097.2 Nonmetallic Inclusions in Welds 1107.3 Metallic Inclusions in Welds 1147.4 Troubleshooting Problems with Inclusions in Welds 115References 116Further Reading 1168 Weld Appearance 1178.1 Can You Judge a Book by Its Cover? Is Beauty Only Skin Deep? 1178.2 Weld Crown Bead Faults 1188.3 Weld Root Bead Faults 1218.4 Fillet Weld Faults 1238.5 Reading Weld Ripple Marks 1248.6 Weld Spatter 1268.7 Arc Strikes 1288.8 Weld Heat Tint 1298.9 Troubleshooting Weld Appearance Problems 132References 133Further Reading 134Part II Location of Problems in Welds 1359 Fusion Zone of Fusion Welds 1379.1 A Refresher on Microstructural Zones in and Around Welds 1379.2 Gas Porosity in the Fusion Zone of Welds 1419.3 Cracking in the Fusion Zone of Welds 1439.4 Inclusions in the Fusion Zone of Welds 1519.5 Macrosegregation in the Fusion Zone of Welds 1529.6 Troubleshooting Problems in the Fusion Zone of Welds 153References 155Further Reading 15610 Partially Melted Zone of Fusion Welds 15710.1 Origin and Location of the PMZ in Fusion Welds 15710.2 Conventional Hot Cracking in the PMZ 16110.3 Constitutional Liquation Cracking in the PMZ 16110.4 Cold Cracking in the PMZ 16410.5 Overcoming Cracking Problems in the PMZ 16610.6 Troubleshooting Problems in the PMZ 167References 167Further Reading 16811 Heat-Affected Zone of Fusion Welds 16911.1 Origin and Location of the HAZ for Fusion Welds 16911.2 Manifestation of Problems in the HAZ of Fusion Welds 17011.3 Precipitation-Hardening Alloy HAZ Problems 17111.4 Sensitization in the HAZ of Austenitic Stainless Steels 17611.5 Transformation-Hardening Steel HAZ Problems 17911.6 Reheat Cracking 18311.7 Troubleshooting Problems in the HAZ of Fusion Welds 186References 187Further Reading 18812 Unaffected Base Metal Cracking Associated with Welding 18912.1 Weld-Related Problems in the Unaffected Base Metal 18912.2 Lamellar Tearing in Thick Steel Weldments 18912.3 Corrosion Cracking Caused by Fusion Welding 19212.4 Fatigue Cracking Outside Fusion Welds 19512.5 Troubleshooting Weld-Related Problems in the Unaffected Base Metal 199References 200Further Reading 20113 Discontinuities in Multi-pass Welds 20313.1 Needs for Multi-pass Welding and Welds 20313.2 Various Functions of Multi-pass Welding and Welds 20513.3 Defects Found in Multi-pass Welds 20713.4 Composition Adjustment with Multi-pass Welding 21013.5 Property Alteration with Multi-pass Welding 21313.6 Troubleshooting Problems in Multi-pass Welding and Welds 216References 217Further Reading 21714 Problems with Non-fusion Welding and Non-fusion Welds 21914.1 Non-fusion Welding Processes Versus Fusion Welding Processes 21914.2 Overview of Non-fusion Processes 22014.2.1 Pressure Welding Processes 22214.2.2 Friction Welding Processes 22214.2.3 Diffusion Welding Processes 22214.2.4 Solid-State Deposition Welding 22314.3 Problems with Non-fusion Welds and Non-fusion Welding Processes 22314.4 Inspection and Repair Challenges with Non-fusion Welds 22914.5 Troubleshooting Problems with Non-fusion Welds 230References 230Further Reading 231Part III Material-Specific Weld-Related Problems 23315 Embrittlement of Carbon and Low- and Medium-alloy Steels 23515.1 The Importance of Steel 23515.2 Four Causes of Embrittlement in Carbon and Low- and Medium-alloy Steels 23815.3 Hydrogen Embrittlement: A Misnomer in Steels 23915.4 Secondary Hardening in Steels 24015.5 Ductile-to-Brittle Transition in Steels 24115.6 Compromise of Fatigue and Impact Behavior by Residual Stresses in Steels 24315.7 Troubleshooting Problems from Embrittlement of Steels by Welding 244References 245Further Reading 24516 Sensitization or Weld Decay and Knife-line Attack in Stainless Steels 24716.1 A Primer on the Metallurgy of Stainless Steels 24716.2 Sensitization of Austenitic Stainless Steels by Welding 24916.3 Sensitization of Other Grades of Stainless Steel 25216.4 Knife-line Attack in Stabilized Austenitic Stainless Steels 25216.5 Troubleshooting Problems from Sensitization or Knife-line Attack 254References 255Further Reading 25517 Stress Relief Cracking of Precipitation-Hardening Alloys 25717.1 Different Names, Same Phenomenon 25717.2 Stress Relief Cracking in Ferritic Alloy Steels 26017.3 Stress Relaxation Cracking in Stainless Steels 26517.4 Strain-age Cracking in Ni-Based Superalloys 26717.5 Troubleshooting Problems from Stress Relief or Strain-age Cracking 270References 271Further Reading 27118 Loss of Properties in Cold-Worked Metals and Alloys 27318.1 Cold Work, Recovery, Recrystallization, and Grain Growth 27318.2 Cold-Worked Metals and Alloys in Engineering 27818.3 Avoiding or Recovering Properties Loss from Fusion Welding 28118.4 The Worked Zone in Pressure-Welded Metals and Alloys 28418.5 Troubleshooting Welding Problems in Cold-Worked Metals and Alloys 285References 285Further Reading 28619 Embrittlement with High-chromium Contents 28719.1 Phase Formation and Structure 28719.2 Adverse Effects of σ-Phase 29119.3 Susceptible Alloys 29119.4 Guidelines for Avoiding or Resolving Problems from σ-Phase 29319.5 Troubleshooting Problems with σ-Phase Associated with Welding 294References 295Further Reading 29520 Weld Dilution and Chemical Inhomogeneity 29720.1 The Designer’s Druthers 29720.2 Chemical Inhomogeneity in Welds 30020.3 Weld Dilution 30220.4 The Unmixed Zone in the Weld Metal 30420.5 Impurities in the Weld Metal 30720.6 Troubleshooting Problems from Weld Dilution and Chemical Inhomogeneity 307References 308Further Reading 30821 Dissimilar Metal and Alloy Welding 30921.1 Joining Dissimilar Materials 30921.2 The Need for Welding Dissimilar Metals and Alloys 31121.3 Chemical Incompatibility 31121.4 Mechanical Incompatibility 31521.5 Thermal Incompatibility 31521.6 Troubleshooting Problems with Dissimilar Metal and Alloy Welding 318References 318Further Reading 319Closing Thoughts 321Index 323