Carbides precipitation and kinetics of H13 steel subjected to deep cryogenic treatment

The influence of deep cryogenic treatment (DCT) on carbides precipitation and isothermal softening behaviour as a function of both temperature and time during tempering of H13 steel was investigated. The results show that the retained austenite transformed into martensite leading to an increase in hardness. The carbon content of martensite decreased after DCT and tempering according to the calculation of the X-ray diffraction spectrum. This indicates that more fine carbides precipitated from the martensitic matrix after DCT. The morphology of microstructure and distribution of carbides have verified the properties improvement mainly depending on the retained austenite transformation and more fine carbides precipitated after tempering. In addition, the carbides precipitating and coarsening are the main causes of thermal softening.

Automated summary

The influence of deep cryogenic treatment (DCT) on carbides precipitation and isothermal softening behavior of H13 steel during tempering was investigated. The results showed that DCT and tempering led to the transformation of retained austenite into martensite, resulting in an increase in hardness. The carbon content of martensite decreased after DCT and tempering, indicating the precipitation of more fine carbides. The improvement in properties was mainly attributed to the transformation of retained austenite and precipitation of fine carbides after tempering. Additionally, carbides precipitation and coarsening were identified as the main causes of thermal softening.