عملیات حرارتی دنده‌ها: راهنمای عملی برای مهندسان

This book is designed to provide engineers with a better understanding of heat treatment and its effects on gear quality and performance, especially as these considerations are critical to ensuring that the gears perform satisfactorily under anticipated service conditions. Increased demand for gears to transmit more power through smaller, lighter, quieter, and more reliable packages that must operate over a wide range of service conditions has made the design and manufacture of gears much more complex. Gears manufactured from certain steels are found to meet these demands, and become especially effective when heat treated and finish machined for high geometric accuracy. However, distortion of the gear after heat treatment offers the engineer a challenging opportunity not only in ensuring a high quality product but also in controlling manufacturing costs. Heat treat distortion of gears is discussed in detail for the major heat treat process, and a case history of each successful gear heat treat process is included. Contents: Introduction to Gear Heat Treatment Properties of Iron Heat Treatment of Gears Through-Hardening Process Carburizing and Hardening Nitriding Modern Nitriding Processes Carbonitriding Induction Hardening Selection of Heat Treat Process for Optimum Gear Design. Contents Preface Chapter 1: Introduction to Gear Heat Treatment Chapter 2: Properties of Iron Alloys of Iron and Carbon Transformation (Decomposition) of Austenite Chapter 3: Heat Treatment of Gears Major Heat Treat Processes Chapter 4: Through-Hardening Gears Through-Hardening Processes Some Hints on Through-Hardened Gear Design Hardness Measurement Heat Treat Distortion of Through-Hardened Gears Applications Case History: Design and Manufacture of a Rack Material Selection Process Selection Chapter 5: Carburizing and Hardening Gears Gas Carburizing Carburizing Temperature Furnaces and Equipment for Gas Carburizing Hardening Direct Quenching Reheating of Carburized Gears and Quenching Surface Hardness Variations after Quenching Tempering of Carburized and Quenched Gears Recarburizing Cold Treatment Selection of Materials for Carburized Gears Hardness and Hardenability Carbon Content and Case Property Core Hardness of Gear Teeth Microstructure of Carburized Cases Some Carburizing Problems Heat Treat Distortion of Carburized and Hardened Gears Mechanics of Heat Treat Distortion Material and Heat Treat Process Factors Vacuum-Melted versus Air-Melted Alloy Steels Measurement of Gear Distortions Some Recommendations to Minimize Distortion Preheating of Gears Distortion Characteristics of Some Gear Materials Improvement in Gear Design to Control Heat Treat Distortion Grinding Stock Allowance on Tooth Flanks to Compensate for Distortion Grinding of Distorted Gears Actual Stock Removal and Tooth Surface Hardness New Pitting Life Distortion Derating Factor Side Effects of Grinding Carburized and Hardened Gears Shot Peening of Carburized and Hardened Gears Heat Treat Characteristics of Two Commonly Used Gear Materials: AISI 4320 and 9310 Carburizing Cost Applications Case History: Distortion Control of Carburized and Hardened Gears New Heat Treat Facilities Tests Conclusions Chapter 6: Nitriding Gears Gas Nitriding Process Recommended Tip and Edge Radii of Teeth White Layer in Nitrided Gears General Recommendations of Nitrided Gears Microstructure of Nitrided Cases and Cores Overload and Fatigue Damage of Nitrided Gears Bending-Fatigue Life of Nitrided Gears Nitriding Cost Distortion in Nitriding European Nitriding Steels Applications Case History A: Nitriding Case History B: Failure of Nitrided Gears Chapter 7: Modern Nitriding Processes Ion/Plasma Nitriding Gears Case History: Application of Ion Nitriding to an Internal Ring Gear at an Epicyclic Gear Box Chapter 8: Carbonitriding Gears Case Depth in Carbonitriding Measurement of Case Depth Materials Distortion Applications Chapter 9: Induction Hardening Gears Materials Pre-Heat Treatment Hardening Patterns Heating with Induction Quenching Tempering Surface Hardness and Case Depth Induction Hardening Problems Applications Recent Advancements in Induction Hardening Dual-Frequency Process Flame Hardening Chapter 10: Selection of Heat Treat Process for Optimum Gear Design Materials Selection Gear Design Feature General Conclusions Chapter 11: Selected References Index A B C D E F G H I J K L M N O P Q R S T V W X Y