Gear Heat Treatment

Gear Heat Treatment

Heat treatment is a heating and cooling process used to achieve desired properties in gear materials. Ferrous gearing may be through hardened or surface hardened when gear rating or service requirements warrant higher hardness and strength for improved fatigue strength or wear resistance.
Common heat treatments for ferrous materials include:

Preheat treatments-Anneal Normalize and temper Quench and temper Stress relief
Heat treatments-Through harden (anneal, normalize, or normalize and temper, and quench and temper). Surface harden profile heated (flame and induction harden) and profile chemistry modified (carburize, carbonitride, and nitride)
Post heat treatment-Stress relieve

Specialized heat treatment for nonferrous materials should be recommended by the producer. and the content of common heat treatment are explain as follows:

Concept of The Gear Heat Treatment
- Annealing - Full
- Annealing - Spheroidizing
- Austempering
- Austenite
- Austenitizing Temperature
- Bainite
- Carbon
- Carbonitriding
- Carburizing Gas
- Case Depth of Carburized Components
- Case Depth of Flame or Induction Harden Components
- Case Depth of Nitrided Components
- Case Hardness
- Cementite
- Combined Carbon
- Core Hardness
- D.I. (Ideal Critical Diameter)
- Decarburization
- Ferrite (alpha)
- Flame Hardening
- Grain Size
- Graphite
- Hardenability
- Hardening
- H-Band Steels
- Induction Hardening
- Jominy End Quenching Hardenability Test
- Martensite
- Microstructure
- Nitriding (Aerated Salt Bath)
- Nitriding (Gas)
- Normalizing
- Pearlite
- Quench and Temper
- Stress Relief
- Surface Hardness
- Tempering
- Test Coupon
- Through Hardening
Through Hardening Processes.
- Annealing
- Normalizing
- Normalizing and Annealing for Metallurgical Uniformity
- Quench and Temper
- Stress Relief
- Heavy Draft, Cold Drawn, Stress Relieved Steel Bars
Flame and Induction Hardening.
- Methods of Flame and Induction Hardening
- Application
- Material
- Prior Heat Treatment
- Hardening Patterns
- Process Considerations
- Rating Considerations
- Specifications
- Documentation
Carburizing.
- Applications
- Materials
- Control With Test Bars
- Specifications
- Carburizing Process Control
Carbonitriding.
- Applications (Advantages and Limitations)
- Materials
- Specification and Inspection
Nitriding.
- Applications
- Materials
- Pre-reatments
- Nitriding Process Procedures
- Specific Characteristics of Nitrided Gearing
- Specifications
Laser heat treating and electron beam heat treating
Quenching.
Distortion
- Causes
- Quenching and Tempering
- Surface Hardened Gearing
Shot Peening.
- Equipment
- Process Control
- Design Consideration
Residual Stress Effects.
- Mechanically Induced Residual Stresses
- Metallurgically Induced Residual Stress