Continuous Cooling Transformation (CCT) Diagram for the AISI H13 Hot Work Tool Steel

Elaboration of Continuous Cooling Transformation (CCT) is tightly connected to the performance of techniques used to find transformation temperatures, especially dilatometric techniques. Dilatometry has became more precise during these last years because of the evolution of electronical components. It is thus possible to detect minor transformations that induce very low dimensional changes, such as little carbides precipitation. This study has permitted the elaboration of a new CCT diagram for the AISI H-13 tool steel which gives more accurately informations on carbides precipitation and other microstructural transformations such as martensitic, bainitic, pearlitic and ferritic depending on cooling rates. These transformations seem to be conditional of previous carbides formation. The knowledge of resulting microstructure for several cooling rates is very important since it can explain microstructural transformations occuring during subsequent tempering.