Theory Regarding Precipitation of. Carbides During Deep Cryogenic. Treatment of 45WCrV7 Tool Steel

Longer cryogenic holding times may decrease the amount of retained austenite and thus increase the amount of carbon available for carbide formation. However, in the case of there isn’t retained austenite in the microstructure, what is the origin and where is appropriate places of the formation of carbide in cryogenic treatment? In this research, first, theoretical study has been done by thermodynamic phenomenon. Second, nine sets of 45WCrV7 tool steel specimens have been deep cryogenic treated and then tempered. After that, experimental study has been done by double deep cryogenic treatment in all sets. Result was: In terms of thermodynamics, deep cryogenic temperature provided the possibility for the formation of 1.55×1017 m/m3 dislocations around the primary carbide with diameter of 2μm which they are facilitate the formation of carbide during tempering. In terms of experiment, in deep cryogenic treatment and during tempering, new carbides precipitated around primary carbides obviously.

Contraction of Phase, Dislocation, Microstructure