Practice Problems: Step-by-Step Microstructure & Phase Percent Calculations

In this video, we solve two detailed TTT practice problems, showing how to predict the final microstructure and phase fractions for steel alloys. You will learn how to:

Draw full cooling paths on TTT diagrams

Identify microconstituents like pearlite, ferrite, bainite, and martensite

Specify pearlite type: coarse, medium, or fine

Apply the lever rule to calculate weight percentages of each phase

Understand how cooling rate and holding time affect phase transformations and the resulting steel properties

These step-by-step examples are designed to help you visualize and understand how heat treatment influences mechanical properties like strength, hardness, and toughness, making the concepts applicable beyond exams to real-world materials engineering.

🎓 To get the most out of this video, review our previous lessons:
1️⃣ Mastering TTT Diagrams: Predict Martensite, Bainite, Pearlite, and Proeutectoid Phases
2️⃣ Mastering Phase Diagrams: Lever Rule, Phase Fractions and Mechanical Strength
3️⃣ Eutectic Alloys in Action: Hypo, Hyper and Weight Fraction Calculations Explained
4️⃣ Hypo vs Hyper Eutectoid Steels: From Austenite to Pearlite and Proeutectoid Phases

📍 Next Up: More advanced heat treatment problems and practical applications

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