Study On Continuous Cooling Transformation Diagrams Of Alloy Steels

Overcooling austenite continuous cooling transformation curves are important bases of determining the technology of heating, rolling, cooling, annealing etc.Using dilatation method and microscopic tests, the expanding curves at different cooling rates were measured and determined with Thermecmastor_Z thermal simulation machine. The expansion curves of phase transformation and the continuous cooling transformation (CCT) curves have been plotted by origin software.Based on the characteristic points on curves, phase transformation points of austenite can be determined and the dynamic continuous cooling transformation (CCT)curve of tested steels were plotted. In addition, by microstructure analyses of optical microscope and SEM, the effects of different cooling rates on phase transformation temperatures were analyzed.The effects of different deformation technologies on Ms (Martensite starting point), Bainite and Pearlite transformations, and the shape and location of CCT diagrams, were discussed. The transformation processes of austenite of alloyed steels during continuous cooling, and the microstructures and properties of transformed phases were studied, which provides the theoretically basis for determining of production technology.