What is CCT diagram of steel?

A continuous cooling transformation (CCT) phase diagram is often used when heat treating steel. These diagrams are used to represent which types of phase changes will occur in a material as it is cooled at different rates.

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 are the limitations of iron carbon phase diagram?

10.9 Two limitations of the iron-iron carbide phase diagram are: 1) The nonequilibrium martensite phase does not appear on the diagram; and 2) The diagram provides no indication as to the time-temperature relationships for the formation of pearlite, bainite, and spheroidite, all of which are composed of the equilibrium …

Which is the TTT diagram for iron carbon?

M The complete TTT diagram for an iron-carbon alloy of eutectoid composition. Imagine, for example, some pure iron that was kept at a temperature of oC ( .. Here is the “official” isothermal TTT diagram for eutectoid carbon steel.

What is the phase diagram for iron carbide?

The iron-iron carbide phase diagram is shown to the left. This describes the phases that will be present under equilibrium cooling (or heating) conditions. The phase changes shown in the diagram will only occur if the diffusion controlled atomic movement are given time to take place. Steels are generally restricted to carbon contents below 1.0%.

How are TTT plots and CCT diagrams used?

This section looks at Phase Diagrams, TTT plots and CCT diagrams. These are important in predicting what alloying components will be present in the affected steel, through different cooling rates. The iron-iron carbide phase diagram is shown to the left.

Why do we need an iron carbon phase diagram?

The service life also improves as phase diagrams show us how to solve problems such as intergranular corrosion, hot corrosion, and hydrogen damage. The iron-carbon phase diagram is widely used to understand the different phases of steel and cast iron. Both steel and cast iron are a mix of iron and carbon.