Isothermal TTT diagram
A diagram that shows how the metal structure changes at constant temperature over time. It helps in analyzing heat treatment processes.
Physical-Chemical Mechanism of Action
The isothermal time-temperature-transformation diagram shows how the metal structure changes at a fixed temperature over time. It illustrates phase transformations and the formation of new crystal structures.
Metallurgical Relevance & Risks in Welding
The diagram is used to determine optimal heat treatment parameters to achieve desired properties like hardness or toughness. Incorrect application can lead to unwanted structures that make the material crack-prone or impair its mechanical properties.
Workshop Practice & Instructions
To use an isothermal TTT diagram correctly, determine the temperature and the time the metal should be exposed to that temperature. Ensure the heat treatment maintains exact temperatures and times to achieve the desired structure. Use specific tools like thermostats or furnace controls to keep the temperature constant.