Steel Heat Treatment: Transformation Diagrams

This lecture covers the transformation diagrams of steel, focusing on the TTT diagram for eutectoid and hypoeutectoid steels, the concept of austenitization, the formation of martensite, bainite, and perlite, and the effects of alloying elements on the transformation process. It also discusses the hardenability of steels, the tempering of martensite, and the secondary hardening phenomenon. Additionally, it explores the importance of isothermal treatments, surface treatments like carburization and nitriding, and the challenges of temper embrittlement. The lecture concludes with a detailed explanation of the tempering process of martensite and the critical role of carbon migration in stabilizing the microstructure.