Which type of transformation diagram TTT or CCT is more important industrially and why?
These are time-temperature transformation (TTT) and continuous cooling transformation (CCT) diagrams. CCT diagrams are generally more appropriate for engineering applications as components are cooled (air cooled, furnace cooled, quenched etc.)
What is the application of the CCT or the TTT diagrams?
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.
Why TTT curve is used?
It shows what structures can be expected after various rates of cooling. It graphically describes the cooling rate required for the transformation of austenite to pearlite, bainite or martensite. TTT diagram also gives the temperature at which such transformations take place.
Which type of curves are used to construct TTT diagrams?
Explanation: S curve, C curve isothermal diagram and Bain’s curve are all names given to time temperature transformation diagrams.
Why TTT curve is used even when iron carbon diagram is already available?
These diagrams are extensively used in the assessment of the decomposition of austenite in heat-treatable steels. We have seen that the iron-carbon phase diagram does not show time as a variable and hence the effects of different cooling rates on the structures of steels are not revealed.
What is a quantitative CCT curve?
The CCT diagrams. containing the quantitative data pertaining to the dependence of. steel structure and hardness on temperature and time of the. supercooled austenite transformations are used for determination of. the structure and hardness of the quenched, normalised, or fully.
How many types of CCT diagrams are there?
How many types of CCT diagram are there? Explanation: There are two types of continuous cooling transformation diagrams which can be drawn. In the two type, some factors are changed to obtain a different curve. Sanfoundry Certification Contest of the Month is Live.
What does TTT diagram stand for?
time-temperature-transformation
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 the difference between CCT and TTT diagram justify your answer with suitable diagram?
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. In general, in CCT diagrams, the transformations of austenite are shifted to lower temperatures and longer times.
What is TTT diagram how TTT diagram is constructed?
Transformation of austenite is plotted against temperature vs time on a logarithm scale to obtain the TTT diagram. The shape of diagram looks like either S or like C. temperature due to low driving force or nucleation rate. At higher under coolings or lower temperature finer pearlite forms.