6522
Elements of Induction Heating: Design, Control, and Applications
By: S. Zinn and S.L. Semiatin; Hardbound; Publisher: ASM; Publication Date: 1988; ISBN 0-87170-308-4; 335 pages
$175.00

This book provides an excellent overview of the range of applications of induction heating with methods by which conventional as well as special heating jobs can be designed around the capabilities of the process.

The book discusses the theory of induction heating, tuning of induction heating circuits and load matching and summarizes major equipment considerations in designing induction heating systems. Design procedures are thoroughly covered for heat treating. The book includes a detailed discussion on fundamentals of process control for a variety of induction heating issues.

Contents:
1 Introduction 1
History 3
Applications of Induction Heating 4
Preheating Prior to Metalworking 6
Heat Treating 6
Melting 6
Welding, Brazing, and Soldering 6
Curing of Organic Coatings 6
Adhesive Bonding 7
Semiconductor Fabrication 7
Tin Reflow 7
Sintering 7
Advantages of Induction Heating 7

2 Theory of Induction Heating 9
Basis for Induction Heating 9
Eddy-Current Distribution in a Solid Bar 13
Equivalent Resistance and Efficiency -- Solid Round Bar 16
Equivalent Resistance and Efficiency -- Other Geometries 21
Determination of Power Requirements 23

3 Tuning of Induction Heating Circuits and Load Matching 27
Tuning of Induction Heating Circuits 28
Series Resonant Circuits 28
True, Reactive, and Apparent Power 30
Parallel Resonant Circuits 31
Tuning Capacitors 32
Transformers and Impedance Matching 35
Impedance Matching and Tuning for Specific Types of Power Supplies 38
Fixed-Frequency Sources 38
Variable-Frequency (Solid-State) Power Sources 41
Radio-Frequency (Vacuum-Tube) Power Supplies 42

4 Induction Heating Power Supplies 47
Frequency and Power Selection Criteria 47
Types of Power Supplies 50
Line-Frequency Induction Heating 50
Frequency Multipliers 55
Motor-Generators 57
Solid-State Inverters 63
Spark-Gap Converters 67
Radio-Frequency (Vacuum-Tube) Power Supplies 67
Radio-Frequency (Solid-State) Equipment 74

5 Auxiliary Equipment for Induction Heating 77
Equipment Cooling Systems 77
Water-Cooling Systems 79
Vapor-Coolant Systems 80
Timers 82

6 Process Design for Specific Applications 85
Design Procedures for Through Heating 85
Selection of Frequency for Through Heating 86
Selection of Power Rating for Through Heating 96
Design Procedures for Heat Treating 105
Surface Hardening 106
Localized Annealing of Steel Pipe Welds 115
Design Procedures for Induction Melting 118
Design Considerations for Coreless Induction Melting Furnaces 120
Design Considerations for Channel Induction Melting Furnaces 127
Design of Induction Pipe Welding Operations 128
Mechanical Design Features 128
Electrical Design Features 133
Design of Induction Brazing and Soldering Operations 135

7 Fundamentals of Process Control 143
Temperature Measurement 144
Thermocouples 144
Radiation Detectors 149
Other Temperature-Measuring Techniques 156
Temperature-Control Modes 163
Proportional Controllers and Heat-Regulating Devices 164
Integration of Control Functions 166
Heating of Steel Slabs 167
Surface Hardening 168
Vacuum Induction Melting 169
Electric-Demand Control 170
Distributed Control 170
Concept of Distributed Control 170
Interfacing/Connecting Control-System Components 173
Miscellaneous Control Technologies Used in Induction Heating 174
Electromagnetic Sorting 174
Resistivity Measurement of Case Depth 177
Calorimetric Evaluation of Induction Hardening 178
Process Simulation 178
Problem Formulation 179
Simulation of Surface Hardening 180

8 Coil Design and Fabrication 185
Basic Design Considerations 185
Basic Coil Designs 188
Low-Frequency Heating 188
Medium-to-High-Frequency Coils 189
Internal Coils 191
Common Design Modifications 193
Coil Characterization 193
Flux Diverters 201
"Balancing" of Multiplace Coils 203
Specialty Coils 205
Master Work Coils and Coil Inserts 206
Coils for Induction Scanners 209
Split Coils 211
Concentrator Coils 212
Butterfly Coils 216
Split-Return Inductors 217
Tapped Coils 217
Transverse-Flux Coils 218
Series/Parallel Coil Construction 220
Tuning Stubs (Trombones) 221
Conveyor/Channel Coils 223
Coil Fabrication 226
Selection of Tubing 227
Coil Forming 228
Joining of Coils to Power-Supply Leads 229
Bracing of Coils 231
Power-Supply Leads 234
Design Considerations 234
Typical Lead Design 237

9 Flux Concentrators, Shields, and Susceptors 241
Flux Concentrators 241
Materials for Flux Concentrators 242
Application of Flux Concentrators 244
Shields 244
Shield Design 245
Typical Applications of Shields 245
Susceptors 247
Susceptor Materials 248
Typical Applications of Susceptors 251

10 Materials Handling 253
Basic Considerations in Materials Handling 253
Part Movement Through Induction Coil 253
Materials for Handling Fixtures 255
Use of Controlled Atmospheres or Vacuum 257
Materials Handling in Induction Billet and Bar Heating 260
Feed Mechanisms 261
Feed-Mechanism Selection Criteria 264
Materials Handling in Induction Heat Treatment 264
Continuous Heat Treatment 266
Heat Treatment of Discrete Parts 269
Materials Handling in Induction Soldering and Brazing 273
Materials Handling in Other Induction Heating Processes 275
Robot Design 278
Robot Drive Mechanisms 279
Robot Tooling Systems and Motions 279
Control and Programming of Robots 279

11 Special Applications of Induction Heating 281
Induction Heating Applications in the Plastics and Rubber
Industries 281
Bonding and Forming of Plastics 281
Plastic Coatings 285
Salvage Operations 287
Bonding Applications of Induction Heating 288
Induction Cap Sealing and Packaging 291
Induction Heating Applications in the Electronics Industry 292
Zone Refining of Semiconductors 293
Growth of Semiconductor Single Crystals 294
Epitaxial Deposition 296
Production of Silicon Solar Cells 298
Hermetic Sealing and Salvage of Electronic Components 298
Manufacture of Vacuum Tubes 300
Induction Heating Applications in the Glass Industry 301
Glass-to-Metal Sealing 301
Glass Melting 302
Lens Blocking 302
Fiber-Optic Manufacture 302
Induction Heating Applications in Steel Finishing 303
Tin Reflow 304
Paint Curing 305
Vessel Heating 306
Application of Induction Heating for Vacuum Processes 308
Vacuum Melting 309
Directional Solidification 310
Levitation Melting 310

12 Economics 315
Cost Elements of Induction Heating 315
Equipment Costs 315
Energy Costs 316
Production Lot Size and Ease of Automation 317
Scale and Scrap Losses 318
Labor Costs 319
Maintenance Costs 319
Other Cost Elements 320
Typical Cost Comparisons 320
Heating of Steel Billets Prior to Forging 320
Heating of Nonferrous Billets Prior to Forging/Extrusion 320
Heat Treating of Steel 321
Tube Welding 323
INDEX 325