Welding Metallurgy and Weldability of Nickel-Base Alloys

John N. DuPont, PhD, is the R.D. Stout Distinguished Professor in the Materials Science and Engineering Department at Lehigh University and Associate Director of the Energy Research Center. A Fellow of both the American Welding Society and ASM International, Dr. DuPont has won numerous awards for his research and teaching, including the Charles H. Jennings Memorial Award., the William Spraragen Memorial Award, the Masubuchi Award., the Lehigh Teaching Excellence Award, and the McKay-Helm award. He and his students have published over 200 articles in the area of solidification, high-temperature corrosion, and welding metallurgy. John C. Lippold, PhD, is a Professor in the Welding Engineering Program and leader of the Welding and Joining Metallurgy Group at The Ohio State University. A Fellow of both the American Welding Society and ASM International, Dr. Lippold has received numerous awards for his research and teaching, including the Charles H. Jennings Memorial Award, the William Spraragen Memorial Award, the McKay-Helm Award, the James F. Lincoln Gold Medal, the Comfort A. Adams Lecture Award, the Plummer Memorial Education Lecture Award, and the IIW Jaeger Lecture Award. Together with his students and colleagues, he has published over 250 articles on welding metallurgy and weldability of structural materials.Samuel D. Kiser is Director of Technology for the Special Metals Welding Products Co., formerly INCO.  He is a professional welding engineer, a Fellow of the American Welding Society, and holds more than ten patents for nickel alloy welding products. Sam is the recipient of the A.F. Davis Silver Medal and the Samuel Wylie Miller Memorial Medal Awards, and has published more than eighty articles and lectured extensively at AWS meetings to audiences around the world.

• Preface xiii1. Introduction 11.1 Ni-base Alloy Classification 21.1.1 Commercially Pure Nickel Alloys 21.1.2 Solid-Solution Strengthened Alloys 31.1.3 Precipitation-Strengthened Alloys 41.1.4 Other Specialty Alloys 51.2 History of Nickel and Ni-base Alloys 51.3 Corrosion Resistance 111.4 Nickel Alloy Production 12References 142. Alloying Additions, Phase Diagrams, and Phase Stability 152.1 Introduction 152.2 General Influence of Alloying Additions 162.3 Phase Diagrams for Solid-Solution Alloys 202.3.1 The Ni-Cu System 202.3.2 The Ni-Cr System 212.3.3 Ni-Mo System 222.3.4 The Ni-Fe-Cr System 222.3.5 Ni-Cr-Mo System 242.4 Phase Diagrams for Precipitation Hardened Alloys—„¶′ƒnFormers 262.5 Phase Diagrams for Precipitation-Hardened Alloys—„¶″ƒnFormers 302.6 Calculated Phase Stability Diagrams 332.7 PHACOMP Phase Stability Calculations 40References 433. Solid-Solution Strengthened Ni-base Alloys 473.1 Standard Alloys and Consumables 473.2 Physical Metallurgy and Mechanical Properties 513.3 Welding Metallurgy 573.3.1 Microstructural Evolution in the Fusion Zone 573.3.2 Heat Affected Zone 813.3.3 Postweld Heat Treatment 823.4 Mechanical Properties of Weldments 913.4.1 Hydrogen Effects 913.4.2 Postweld Heat Treatment 933.5 Weldability 1003.5.1 Fusion Zone Solidification Cracking 1003.5.2 HAZ Liquation Cracking 1183.5.3 Avoiding Solidification and Liquation Cracking 1233.5.4 Ductility-Dip Cracking 1283.6 Corrosion Resistance 1433.7 Case Studies 1493.7.1 Pitting Corrosion in MONEL® Welds 149References 1504. Precipitation-Strengthened Ni-base Alloys 1574.1 Standard Alloys and Consumables 1584.2 Physical Metallurgy and Mechanical Properties 1614.3 Welding Metallurgy 1734.3.1 Microstructural Evolution in the Fusion Zone 1734.3.2 Heat-Affected Zone 2014.3.3 Postweld Heat Treatment 2044.4 Mechanical Properties of Weldments 2064.5 Weldability 2074.5.1 Solidification Cracking 2084.5.2 HAZ Liquation Cracking 2234.5.3 Strain-Age Cracking 235References 2485. Oxide Dispersion Strengthened Alloys and Nickel Aluminides 2555.1 Oxide Dispersion Strengthened Alloys 2555.1.1 Physical and Mechanical Metallurgy 2555.1.2 Welding Metallurgy 2595.1.3 Summary of the Weldability of ODS Alloys 2685.2 Nickel Aluminide Alloys 2685.2.1 Physical and Mechanical Metallurgy 2685.2.2 Weldability of the Ni-Aluminides 2725.2.3 Summary of the Weldability of Nickel Aluminide Alloys 276References 2786. Repair Welding of Ni-base Alloys 2816.1 Solid-Solution Strengthened Alloys 2816.2 Precipitation-Strengthened Alloys 2836.2.1 Alloy 718 2846.2.2 Waspaloy 2956.3 Single Crystal Superalloys 2986.3.1 Control of Single Crystal Weld Repairs 3026.3.2 Solidification Cracking 3146.3.3 Optimizing Processing Parameters 317References 3247. Dissimilar Welding 3277.1 Application of Dissimilar Welds 3277.2 Influence of Process Parameters on Fusion Zone Composition 3287.3 Carbon, Low Alloy and Stainless Steels 3317.3.1 Determining Weld Metal Constitution 3327.3.2 Fusion Boundary Transition Region 3347.3.3 Weldability 3427.4 Postweld Heat Treatment Cracking in Stainless Steels Welded with Ni-base Filler Metals 3477.5 Super Austenitic Stainless Steels 3497.6 Dissimilar Welds in Ni-base Alloys—Effect on Corrosion Resistance 3577.7 9%Ni Steels 3577.7.1 Physical Metallurgy of 9%Ni Steels 3577.7.2 Hot Cracking of Ni-base Deposits 3617.8 Super Duplex Stainless Steels 3637.9 Case Studies 3647.9.1 Postweld Heat Treatment Cracking of Thick Section Welds in Alloy 800H Made withENiCrFe-2 Filler Metal 3647.9.2 Alloy 925 Welded with ERNiCrMo-15 (INCO-WELD 725NDUR) for Manufacturing Vacuum Insulated Oil Patch Tubing 3677.9.3 Corrosion-Fatigue of Alloy 625 Weld Overlays 3697.9.4 Overlay of “Safe-End” Welds using High-Cr, Ni-base Filler Metals 373References 3768. Weldability Testing 3798.1 Introduction 3798.1.1 Weldability Testing Approaches 3808.1.2 Types of Weldability Test Techniques 3808.2 The Varestraint Test 3818.2.1 Technique for Quantifying Weld Solidification Cracking 3838.2.2 Technique for Quantifying HAZ Liquation Cracking 3868.3 Modified Cast Pin Tear Test 3888.4 The Sigmajig Test 3928.5 The Hot Ductility Test 3948.6 The Strain-to-Fracture Test 3998.7 Other Weldability Tests 401References 402Appendix A Composition of Wrought and Cast Nickel-Base Alloys 403Appendix B Composition of Nickel and Nickel Alloy Consumables 409Appendix C Corrosion Acceptance Testing Methods 415Appendix D Etching Techniques for Ni-base Alloys and Welds 419Author Index 423Subject Index 431