What is Triple T diagram?

TTT diagram stands for “time-temperature-transformation” diagram. It is. also called isothermal transformation diagram. Definition: TTT diagrams give the kinetics of isothermal transformations.

What is shown by TTT diagram?

The TTT diagram is really a simplified diagram of the kinetics of pearlite and bainite formation, and the diffusion-less transformation of martensite. It is a diagram of overlapping curves (Figure 6). The shape and position of the curves depend on the alloy composition, grain size, and carbon content.

Why TTT diagram is used?

The effect of time-temperature on the microstructure changes of steel can be shown by the TTT diagram. These diagrams are extensively used in the assessment of the decomposition of austenite in heat-treatable steels.

What is TTT curve in material science?

What Is the TTT diagram in Material Science? TTT diagram of steel is called isothermal transformation diagram or time-temperature-transformation diagram. It presents a logarithmic plot between temperature and time.

What is the difference between TTT and CCT diagrams?

The primary difference between TTT diagrams and CCT diagrams is that TTT diagrams examine the progress of transformation as a function of time, at a fixed temperature. CCT diagrams examine the progress of transformation as a function of changing temperature.

What is the difference between phase diagram and TTT diagram?

Phase diagrams map the system at equilibrium. TTT diagrams map the kinetics to get to equilibrium.

What is TTT diagram for eutectoid steel?

Time-Temperature-Transformation (TTT) diagram or S-curve refers to only one steel of a particular composition at a time, which applies to all carbon steels. This diagram is also called as C-curve isothermal (decomposition of austenite) diagram and Bain’s curve.

What is bainite microstructure?

Bainite is a microstructure made up of packets of parallel plates in the so-called morphological packet. The good toughness of this microstructure could be related to the high density of the high-angle boundaries that these microstructures usually present (124).

What is the significance of TTT diagram in the heat treatment of steel?

The time and the temperature of holding is given by the TTT curve of the steel. As the isothermal annealing is normally done to soften the steel, the temperature of isothermal holding is very close to but below A1 (by 30- 100°C).

What is difference between iron carbon diagram and TTT diagram?

Explanation: ​The iron-carbon diagram is drawn under equilibrium conditions but the T-T-T diagram is drawn under non-equilibrium conditions. Iron – Carbon phase diagram, the temperature is plotted against composition.

What is the difference between pearlite and bainite?

The key difference between pearlite and bainite is that the pearlite contains alternating layers of ferrite and cementite whereas the bainite has a plate-like microstructure. The names pearlite and bainite refer to two different microstructures of steel.