Handbook of Induction Heating, Second Edition

Content: 1. INTRODUCTION     2. OVERVIEW OF INDUSTRIAL APPLICATIONS OF INDUCTION HEATING     2.1. Heat treatment by induction     2.1.1. The basics of metallurgy and principles of heat treatment     2.1.1.1. Crystalline structure of elements and critical temperatures     2.1.1.2. Equilibrium phase transformation diagram     2.1.1.3. Time-Temperature Transformation (TTT) diagram and Continuous Cooling Transformation (CCT) diagram     2.1.1.4. Steel's trace elements and alloying elements     2.1.1.5. Concept of hardenability     2.1.1.6. Effect of heat intensity (heating rate) on induction heat treatment results     2.1.1.7. Effect of prior microstructure of steel     2.1.1.8. Specifics of hardening martensitic stainless steels     2.1.1.9. Induction heat treatment of cast irons     2.1.2. Hardening     2.1.3. Tempering and stress relieving     2.1.4. Normalizing     2.1.5. Annealing     2.1.6. Spheroidizing     2.1.7. Sintering     2.1.8. Heat treating of light metals     2.2. Induction mass heating     2.2.1. Bar, rod and billet reheating     2.2.2. Slug heating for semisolid forming     2.2.3. Tube, pipe and vessel heating     2.2.4. Wire, rod and cable heating     2.2.5. Slab, plate, rectangular bar and bloom heating     2.2.6. Induction heating of strips, thin slabs, plates and sheets     2.2.7. Coating     2.3. Special applications of induction heating     2.3.1. Joining, friction welding, brazing, bonding and soldering     2.3.2. Shrink fitting     2.3.3. Banding     2.3.4. Motor rotor heating (lamination bluing and bond breaking)     2.3.5. Seam annealing     2.3.6. Food industry     2.3.7. Papermaking     2.3.8. Wool and wood processing     2.3.9. Chemical industry     2.3.10. Automotive sealing     2.3.11. Cap sealing     2.3.12. Die heating     2.3.13. Miscellaneous     2.4. Induction melting     2.4.1. Induction channel-type furnaces     2.4.2. Induction crucible-type (coreless) furnaces     2.4.3. Induction vacuum furnace     2.5. Induction welding     3. THEORETICAL BACKGROUND     3.1. Basic electromagnetic phenomena in induction heating     3.1.1. Electromagnetic properties of metals     3.1.2. "Skin" effect     3.1.3. Electromagnetic proximity effect     3.1.4. Electromagnetic slot effect     3.1.5. Electromagnetic ring effect     3.1.6. Electromagnetic force     3.1.7. Introduction to electromagnetic end and edge effects     3.2. Basic thermal phenomena in induction heating     3.2.1. Thermal properties of the materials     3.2.2. Three modes of heat transfer
 conduction, convection, and radiation     3.3. Estimation of the required power and dynamics of induction heating     3.3.1. Estimation of the required power for induction heating     3.3.2. Intricacies of the dynamics of induction heating     3.4. Advanced induction principles and mathematical modeling     3.4.1. Mathematical modeling of the electromagnetic field2     3.4.2. Mathematical modeling of the thermal processes     3.4.3. Numerical computation of the process     3.4.4. Pros and Cons of generalized all-purpose software     3.4.5. Review of application-oriented programs     3.4.6. Case studies     4. HEAT TREATMENT BY INDUCTION     4.1. Machine design for induction surface and through hardening     4.1.1. Heating modes     4.1.1.1. Static heating mode     4.1.1.2. Scan heating mode     4.1.1.3. Progressive heating mode     4.1.1.4. Pulse heating mode     4.1.2. Frequency choice and power density     4.1.3. Duration of heat for surface hardening     4.1.4. Inductor styles     4.1.4.1. Scan inductors     4.1.4.2. Progressive inductors     4.1.4.3. Single-shot inductors     4.1.4.4. Special inductors     4.1.4.5. Specifics of designing of inductors for heating interior surfaces     4.1.4.6. Induction proximity heating of flat and plane surfaces     4.1.4.7. Inductors with inserts     4.1.4.8. Coupling gaps     4.1.4.9. "Profiled" coils     4.1.4.10. Fabrication of inductors.     4.1.4.11. Inductors for heating of irregular shapes     4.1.5. "Striping" phenomena, barber pole effect, "fish-tail" and snakeskin (soft-spotting) phenomenon     4.1.6. Quenching and spray quench designs. Quench maintenance.     4.1.7. Cooling of induction coils and tubing selection     4.1.8. Inductor mounting styles     4.1.9. Accessory equipment and work handling     4.2. Induction heat treatment of crankshafts, camshafts and axle shafts     4.2.1. Crankshaft heat treatment by induction     4.2.2. Induction hardening of camshafts     4.2.3. Hardening shafts     4.3. Gear hardening     4.3.1. Materials selection and required gear conditions prior to heat treatment     4.3.2. Overview of hardness patterns     4.3.3. Coil designs and heat modes     4.3.3.1. "Tooth-by-tooth" and "gap-by-gap" inductors     4.3.3.2. Gear spin hardening (encircling inductors)     4.3.3.2.1. Single frequency systems     4.3.3.2.2. Dual frequency technology     4.3.3.2.3. Simultaneous dual frequency gear hardening.     4.3.4. Lightening holes (weight reduction holes)     4.3.5. Powdered metal gears     4.3.6. TSH technology for gear hardening     4.4. Induction hardening of wind energy components     4.5. Tempering     4.5.1. Metallurgical aspects of tempering and stress relieving     4.5.2. Self-tempering ("slack quenching")     4.5.3. Induction tempering and its features     4.5.4. FluxManager technology for stress relieving pipe ends     4.5.5. Oven tempering vs. induction tempering     4.6. Induction heat treating of powder metals     4.7. Electromagnetic end and edge effects in induction hardening and tempering     4.8. Longitudinal and transverse holes, key ways, grooves, various oriented hollow areas     4.9. Stresses in heat treating and control of excessive distortion and cracking in induction heat treating     4.9.1. Initial stresses     4.9.2. Transitional stresses     4.9.3. Residual stresses     4.9.4. Effect of tempering and grinding of stress distribution     4.10. Root causes of cracking and excessive part's distortion and ways to avoid it     4.10.1. Distortion control of heat treated components     4.10.2. Review of root-causes of cracking     4.10.2.1. Part's geometry factors     4.10.2.2. Microstructure related factors3     4.10.2.3. Process recipe selection     4.10.3. Fishbone diagram of cracking     4.10.4. Aspects of failure analysis and good practice to prevent crack developing     4.11. Magnetic flux control techniques: magnetic shields, magnetic shunts, and magnetic flux concentrators (intensifiers)     4.11.1. Electromagnetic shields     4.11.2. Magnetic shunts     4.11.3. Magnetic flux concentrators (flux intensifiers)     4.11.3.1. Physics of the magnetic flux concentration     4.11.3.2. Design and application features     4.11.3.3. Selection of flux concentrator materials     4.11.3.4. Advantages and drawbacks of using magnetic flux concentrators     4.11.3.5. Case studies     4.12. Coil maintenance and storage     4.13. Simple solutions for solving typical induction heat treating problems. Practical recommendations. Case studies.     4.14. Quality assurance and non-destructive testing (NDT) of induction hardened parts.     5. SPECIAL APPLICATIONS OF INDUCTION HEATING     5.1. Joining applications     5.1.1. Brazing and soldering by induction     5.1.2. Bonding     5.1.3. Cap sealing     5.1.4. Shrink fitting     5.2. Induction melt-out (lost-core technology)     5.3. Motor rotor heating     5.4. Die heating     6. INDUCTION HEATING PRIOR TO HOT AND WARM FORMING     6.1. Applications, design approaches and fundamental principles of induction mass heating prior to metal hot working     6.2. Steel related subtleties     6.2.1. Plain carbon steels     6.2.2. Alloyed steels     6.2.3. Microalloyed (HSLA) steels     6.2.4. Aerospace alloys and super alloys     6.2.5. Cast steels vs. wrought steels.     6.3. In-line induction heating of long cylindrical bars and rods     6.3.1. Electro-thermal nature of inline induction heating     6.3.2. Longitudinal and transverse cracks     6.3.3. Transient processes and "nose-to-tail" temperature profiles     6.3.4. Energy efficiency of inline bar and rod heaters     6.3.5. Modular concept in designing induction heaters. InductoForge Technology.     6.4. Billet heating     6.4.1. Induction heating of steel billets     6.4.2. Induction heating of non-ferrous billets     6.5. Bar/Billet/Rod end heater     6.6. Slug heating for semi-solid processing     6.7. Intricacies of induction wire/cable/rope heating     6.7.1. Specifics of design criteria and coil arrangements     6.7.2. Frequency selection and energy efficiency     6.7.3. Commercial induction wire, cable, and rope heaters     6.8. Tube and pipe heating     6.8.1. Specifics of induction heating of tubular products     6.8.2. In-line induction heating of tubes and pipes and their applications     6.8.3. Selective heating of tubular products and case studies of typical applications     6.9. Slab, plate, bloom and rectangular bar heating     6.9.1. General remarks     6.9.2. Longitudinal electromagnetic end effect of a rectangular workpiece     6.9.3. Electromagnetic transverse edge effect     6.9.4. Design concepts of induction slab heating systems and case studies of commercial installations     6.9.4.1. Static heating     6.9.4.2. Inline continuous heating     6.9.4.3. Oscillating heating     6.10. In-line induction heating of strip, sheet, plate, thin slab and transfer bar     6.10.1. Strip coating processes     6.10.1.1. Metallic coating of strips (galvanizing, galvaluming, galvannealing, tinning)     6.10.1.2. Nonmetallic coatings     6.10.2. Coil design approaches for heating strips, plates, sheets and thin slabs     6.10.2.1. Longitudinal flux inductor (solenoid coil)     6.10.2.2. Transverse flux induction heater (TFIH)4     6.10.2.3. Travelling wave induction heater (TWIH)     6.10.2.4. Channel-type coils     6.10.2.5. C-core inductors     6.10.2.6. Doorless technology for strip processing lines     6.11. Material handling     6.11.1. Billet handling     6.11.2. Handling of long bars, rods and tubes     6.11.3. Slab, plate and transfer bar handling     7. POWER SUPPLIES FOR MODERN INDUCTION HEATING     7.1. Power-Frequency combinations     7.2. Elements of power electronics     7.2.1. Inductors     7.2.2. Capacitors     7.2.3. Vacuum tubes and power semiconductors     7.2.3.1. SCR or thyristor     7.2.3.2. Diod or rectifier     7.2.3.3. Transistors     7.2.3.4. Vacuum tube oscillators     7.2.3.5. Power-frequency applications of semiconductors and vacuum tubes     7.3. Types of induction heating power supplies     7.3.1. Rectifier or converter section     7.3.2. Inverter section     7.3.2.1. Full-bridge inverter     7.3.2.2. Half-bridge inverter     7.3.2.3. Voltage-fed inverters with simple series load     7.3.2.4. Voltage-fed inverters with series connection to a parallel load     7.3.2.5. Current-fed inverters     7.3.2.6. Single switch inverter     7.3.3. Operational considerations     7.3.3.1. Initial cost     7.3.3.2. Operating cost     7.3.3.3. Reliability and maintainability     7.3.3.4. Flexibility     7.4. Load matching     7.5. Medium and high-frequency transformers for heat treating and mass heating     7.6. Special considerations for power supplies     7.7. Special considerations for induction brazing, soldering, and bonding     7.8. Special considerations for induction heating power supplies in mass heating applications     7.9. Special considerations for induction heating power supplies in strip processing applications     7.10. Simultaneous dual frequency inverters     7.11. Inverters with independent frequency and power control (IFP-type invertors)     7.12. Comparison of solid-state power supplies and vacuum tube oscillators     7.13. The importance of having a good power factor     7.14. Harmonics and their reduction     7.14.1. Nature and cause of harmonics     7.14.2. Solutions to power factor and harmonic problems     7.15. Power supply cooling     7.15.1. Water quality     7.15.2. Cooling water flow rate     7.15.3. Cooling water re-circulating systems     7.15.4. Common water-cooling problems     7.16. Process control, monitoring, and quality assurance     7.16.1. Prelude to discussion of process control and monitoring     7.16.1.1. Specifics of control and monitoring of induction metal heat treating processes     7.16.1.2. Specifics of control and monitoring of induction mass heating     7.16.2. Meters and meter circuits     7.16.3. Features of control / monitoring strategies for induction heat treating vs. induction mass heating     7.16.4. Basic principles of feed back and control algorithms     7.16.5. Energy monitoring     7.16.6. Advanced monitoring and "signature" analysis     7.16.7. Protective devices and safety principles     7.16.8. Final remarks     REFERENCES     APPENDIXES     INDEX