Iron Metallurgy 201


"This class was very informative and brought me up to speed on metallurgical terms and processing of cast iron."


This course provides participants with the knowledge and skills regarding terminology, principles, and techniques for the metallurgy of gray and ductile iron casting alloys. Topics include equilibrium phase diagrams, kinetics (rates of change), eutectic solidification, undercooling, graphite shapes in gray and ductile iron, effects of alloying elements, eutectoid reaction in cast irons, mechanical testing, and defects related to metallurgy.

Benefits to taking this course include hands-on identification of the basic phases on the iron-carbon phase diagram, identifying major phases and characteristics from microstructures, explaining solidification behaviors and reactions, identifying preparation and analysis techniques of metallographic samples and discussing iron casting defects specifically related to metallurgy.

Learning outcomes

Course participants will learn to:

  • Recognize and describe the fundamentals of the Fe-C/Fe3C equilibrium (phase) diagram and the effect of adding silicon.
  • Describe the concepts of equilibrium and kinetics (speed of reactions).
  • Identify and explain the solidification (eutectic) reactions that produce graphite and Fe3.
  • Describe the solidification behavior of ductile iron vs. gray iron vs. white iron.
  • Describe the process for pearlite formation in graphitic cast irons.
  • Relate solidification behavior to key points on cooling curves for various irons.
  • Describe the analysis of metallographic samples for cast irons, including phase identification.
  • Describe the major types and applicability of mechanical testing methods for irons.
  • Recognize metallurgical defects in gray and ductile iron and tools and procedures for identifying them.

Course Length

2.0 days

CEU Units

1.20 CEU

Course outline

Module 1: Introduction
Module 2: Introduction to Equilibrium (Phase) Diagrams

•    Basic Concepts
•    Two Component Systems

Module 3: The Iron-Carbon System

•    Phase Fields on the Fe-C Equilibrium Diagram
•    Metallographic Appearance of Major Phases

Module 4: Eutectic Solidification

•    Definitions and Eutectic Reactions in Cast Irons
•    Basic Concepts of Cast Iron Solidification
•    Undercooling

Module 5: Graphite Shape in Gray and Ductile Iron

•    Nucleation of Graphite During Solidification
•    Growth of Graphite During Solidification

Module 6: Effects of Carbon, Silicon, and Other Elements on Solidification

•    Effects of Silicon on Fe-C Phase Diagram
•    Casting Properties
•    Effects of Some Other Elements

Module 7: The Eutectoid Reaction in Cast Irons

•    The Generic Eutectoid Reaction
•    Pearlite-stabilizing Elements

Module 8: Insights on Mechanical Testing

•    Tensile Testing
•    Hardness Testing
•    Impact Testing

Module 9: Iron Related Casting Issues

•    Porosity/Cavity Defects
•    Abnormal Graphite Types
•    Poor Machinability

Module 10: Conclusion