Heat Treatment Course

Lesson 1 • Heat Transfer Principles in Metals

Covers conduction, convection, and radiation as applied to metal heating and cooling. Establishes thermal gradient concepts critical for quench design.

Lesson 2 • Atomic Structure and Metallic Bonding

Covers crystal lattices, unit cells, and metallic bonding types. Provides the atomic-level foundation needed to understand all subsequent phase transformations.

Lesson 3 • Iron-Carbon Phase Diagram Basics

Introduces the Fe-C equilibrium diagram, key phases, and invariant reactions. Directly links phase regions to heat treatment temperature selection.

Lesson 4 • Solid-State Transformations Overview

Explains diffusion-controlled and diffusionless transformations. Connects transformation type to resulting microstructure and mechanical properties.

Lesson 1 • Stress Relief Annealing

Addresses residual stress origins from welding, forming, and machining. Specifies temperature-time cycles that reduce stress without altering bulk microstructure.

Lesson 2 • Process and Spheroidize Annealing

Covers subcritical and intercritical cycles that produce spheroidal carbides. Targets improved machinability in high-carbon and tool steels.

Lesson 3 • Principles of Annealing

Defines recovery, recrystallization, and grain growth stages. Explains how each stage alters dislocation density and mechanical response.

Lesson 4 • Normalizing: Process and Applications

Distinguishes normalizing from full annealing via air cooling and its effect on grain refinement. Identifies applications where normalized structure is preferred.

Lesson 1 • Ideal Critical Diameter and H-Values

Introduces DI concept and Grossmann multiplying factors for alloying elements. Enables hardenability prediction without running physical tests.

Lesson 2 • Hardenability Bands and Steel Grades

Explains H-steel designation system and hardenability band charts. Learners match part cross-section to appropriate H-grade steel.

Lesson 3 • Jominy End-Quench Test

Details the standardised end-quench procedure and hardness traverse measurement. Learners interpret Jominy curves to predict hardness at any bar position.

Lesson 4 • Hardenability Concept and Importance

Defines hardenability as depth of hardening, not maximum hardness. Distinguishes hardenability from hardness and explains its design significance.

Lesson 1 • TTT and CCT Diagrams

Explains time-temperature-transformation and continuous cooling transformation diagrams. Learners use these to predict microstructure from any cooling path.

Lesson 2 • Austenitising for Hardening

Covers temperature selection above Ac3, carbide dissolution, and homogenisation. Establishes how incomplete austenitising limits achievable hardness.

Lesson 3 • Quenching Media and Severity

Compares water, oil, polymer, gas, and salt quenchants by cooling rate and severity. Links quenchant choice to steel hardenability and part geometry.

Lesson 4 • Quench Distortion and Cracking Control

Identifies thermal and transformational stress sources during quenching. Provides design rules for fixturing, part orientation, and interrupted quenching.

Lesson 1 • Secondary Hardening in Alloy Steels

Explains precipitation of alloy carbides (Mo, W, V, Cr) during high-temperature tempering. Targets tool steel and high-speed steel applications.

Lesson 2 • Tempering Temperature and Time Selection

Uses Hollomon-Jaffe parameter to correlate temperature-time combinations. Enables equivalent tempering cycle design for different furnace constraints.

Lesson 3 • Temper Embrittlement Phenomena

Covers 260–370°C and 450–550°C embrittlement mechanisms and causative elements. Teaches avoidance strategies through alloy selection and cooling rate control.

Lesson 4 • Cryogenic Treatment Integration

Addresses sub-zero treatment to convert retained austenite before tempering. Quantifies dimensional stability and wear resistance improvements.

Lesson 1 • Carburising: Pack, Gas, and Vacuum

Explains carbon diffusion into low-carbon steel surfaces to create a high-carbon case. Compares pack, atmosphere, and vacuum carburising in terms of control and quality.

Lesson 2 • Carbonitriding Process

Combines carbon and nitrogen co-diffusion at intermediate temperatures. Targets thin-case, high-volume production parts requiring improved hardenability.

Lesson 3 • Flame and Induction Hardening

Covers rapid surface austenitising by flame and electromagnetic induction followed by quench. Addresses frequency selection, power density, and pattern control.

Lesson 4 • Nitriding and Nitrocarburising

Details nitrogen diffusion at subcritical temperatures to form hard compound and diffusion zones. Highlights distortion advantages over carburising.

Lesson 1 • Furnace Types and Heating Methods

Surveys batch, continuous, pit, and vacuum furnaces by heating method and application. Matches furnace type to production volume and part geometry.

Lesson 2 • Controlled Atmosphere Systems

Explains endothermic, exothermic, nitrogen-methanol, and vacuum atmospheres. Covers carbon potential measurement and control to prevent decarburisation or carburising.

Lesson 3 • Temperature Measurement and Control

Covers thermocouple types, placement, and calibration for accurate thermal control. Addresses uniformity surveys and AMS 2750 compliance concepts.

Lesson 4 • Furnace Loading and Fixturing

Addresses fixture materials, loading patterns, and their effect on temperature uniformity. Minimises distortion through proper support and spacing.

Lesson 1 • Non-Destructive Testing Methods

Covers magnetic particle, dye penetrant, ultrasonic, and eddy current inspection. Selects NDT method based on defect type and part geometry.

Lesson 2 • Metallographic Examination

Covers sectioning, mounting, grinding, polishing, and etching for microstructure evaluation. Links observed microstructure to process compliance or deviation.

Lesson 3 • Hardness Testing Methods

Compares Rockwell, Vickers, Brinell, and Knoop scales for different applications. Establishes correct scale selection, surface preparation, and conversion accuracy.

Lesson 4 • Distortion Measurement and Analysis

Introduces CMM, straightness gauging, and roundness measurement for distortion quantification. Connects distortion patterns to root causes in the heat treatment cycle.