Steel Metallurgy Course

Lesson 1 • Common Alloying Elements in Steel

Surveys manganese, silicon, chromium, nickel, and molybdenum additions. Connects each element to specific property improvements relevant to industrial applications.

Lesson 2 • Carbon in Iron: Key Concepts

Explains how carbon dissolves in iron and forms interstitial solid solutions. Links carbon content directly to hardness, strength, and ductility outcomes.

Lesson 3 • Steel Classification Systems

Introduces designation systems for carbon and alloy steels by composition. Enables students to read and interpret standard steel grades used in industry.

Lesson 1 • Phase Diagram Fundamentals

Reviews Gibbs phase rule and binary phase diagram construction. Establishes the vocabulary of phases, fields, and invariant reactions used throughout the course.

Lesson 2 • Alloying Effects on the Phase Diagram

Shows how alloying elements shift critical temperatures and phase boundaries. Prepares students to interpret modified diagrams for alloy steels.

Lesson 3 • Critical Temperatures and Reactions

Identifies A1, A3, and Acm lines and the eutectic and eutectoid reactions. Students calculate phase fractions at any temperature and composition.

Lesson 4 • Pearlite and Proeutectoid Phases

Explains the formation of pearlite lamellae and proeutectoid ferrite or cementite. Connects microstructural morphology to cooling rate and carbon content.

Lesson 1 • CCT Diagrams: Continuous Cooling

Translates isothermal TTT data to continuous cooling transformation diagrams. Enables prediction of microstructure for real industrial cooling processes.

Lesson 2 • Nucleation and Growth Principles

Covers classical nucleation theory and diffusion-controlled growth in solids. Provides the mechanistic basis for all transformation kinetics discussed in this section.

Lesson 3 • Bainite: Structure and Formation

Distinguishes upper and lower bainite morphologies and their formation mechanisms. Links bainite microstructure to toughness and strength combinations.

Lesson 4 • TTT Diagrams: Isothermal Transformations

Constructs and reads time-temperature-transformation diagrams for plain carbon and alloy steels. Students predict phase products from isothermal hold conditions.

Lesson 1 • Normalising Treatment

Defines normalising as air cooling from above the upper critical temperature. Distinguishes normalised microstructure and properties from fully annealed steel.

Lesson 2 • Tempering of Martensite

Describes the four stages of tempering and their effects on hardness and toughness. Students select tempering temperatures to meet specific mechanical property targets.

Lesson 3 • Annealing: Types and Purposes

Covers full annealing, process annealing, and spheroidising with their temperature ranges. Each treatment is linked to softening, stress relief, or machinability improvement.

Lesson 4 • Quenching: Media and Mechanisms

Compares water, oil, polymer, and gas quenching media by severity and distortion risk. Students select quench media based on steel grade and section size.

Lesson 1 • Fracture Mechanics Basics

Introduces stress intensity factor K and fracture toughness KIc for steel components. Enables students to assess critical flaw sizes in structural steel applications.

Lesson 2 • Impact Toughness and Ductile-Brittle Transition

Explains Charpy and Izod impact tests and the ductile-to-brittle transition temperature. Connects DBTT to steel composition, grain size, and heat treatment.

Lesson 3 • Fatigue Behaviour of Steel

Introduces S-N curves, endurance limit, and fatigue crack initiation mechanisms. Relates surface condition, residual stress, and microstructure to fatigue life.

Lesson 4 • Hardness Testing Methods

Compares Rockwell, Brinell, Vickers, and Knoop hardness scales and their applications. Students select the appropriate test for a given material condition and geometry.

Lesson 1 • Ideal Diameter and Grossmann Method

Introduces ideal critical diameter (DI) and multiplying factors for alloying elements. Enables calculation of expected hardness depth for any steel composition.

Lesson 2 • Selecting Steel for Hardenability

Applies hardenability data to select the minimum-alloy grade meeting a design requirement. Balances cost, weldability, and hardenability in grade selection decisions.

Lesson 3 • Alloying Elements and Hardenability

Quantifies how boron, manganese, chromium, and molybdenum increase hardenability. Students predict hardenability changes from compositional adjustments.

Lesson 4 • Hardenability Concepts and Importance

Defines hardenability as depth of hardening, distinct from surface hardness. Explains why hardenability governs heat treatment success for structural components.

Lesson 1 • Nitriding and Nitrocarburising

Explains gas and plasma nitriding mechanisms producing compound and diffusion zones. Compares nitriding to carburising in terms of temperature, distortion, and surface hardness.

Lesson 2 • Carburising: Principles and Practice

Covers gas, liquid, and vacuum carburising mechanisms and process variables. Students calculate carbon profiles and case depths from diffusion equations.

Lesson 3 • Quality Control of Case-Hardened Parts

Defines effective case depth, total case depth, and core hardness acceptance criteria. Students apply metallographic and hardness traversal methods to verify case quality.

Lesson 4 • Flame and Induction Hardening

Describes selective surface austenitising by flame or induction heating followed by quenching. Students specify frequency, power, and scan rate for target case depth.

Lesson 1 • Tool Steels and Die Steels

Classifies tool steels by application: cold work, hot work, high-speed, and shock-resistant. Students match tool steel grade to service temperature, wear, and toughness demands.

Lesson 2 • Structural and Construction Steels

Covers high-strength low-alloy (HSLA) and structural carbon steels for construction use. Links controlled rolling and microalloying to yield strength and weldability.

Lesson 3 • Stainless Steels

Covers austenitic, ferritic, martensitic, duplex, and precipitation-hardening stainless families. Students select stainless grades based on corrosion environment and mechanical requirements.

Lesson 4 • Bearing and Gear Steels

Identifies cleanliness, hardenability, and fatigue requirements for bearing and gear applications. Links inclusion control and case hardening to rolling contact fatigue life.