Effect of deep cryogenic treatment on carbon segregation in Cr8Mo2SiV tool steel during tempering |
| |
| Authors: | Chen Xie Longmei Zhou Na Min |
| |
| Affiliation: | 1. State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai, China;2. Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai University, Shanghai, China;3. School of Materials Science and Engineering, Shanghai University, Shanghai, China |
| |
| Abstract: | Carbon segregation in Cr8Mo2SiV tool steel after common heat treatment (CHT) and deep cryogenic treatment (DCT) has been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) extraction replica and three-dimensional atom probe (3DAP) tests. The XRD results show that most of the retained austenite transformed to martensite after DCT. The TEM results confirm the transformation of blocky retained austenite to twin martensite during DCT. The 3DAP results reveal the segregation of carbon atoms and the maximum carbon fraction in carbon-rich regions increases after DCT. The peak carbon concentration in carbon-rich regions of SDC99 steel after CHT and DCT are 8 at. % and 15 at. %, respectively. The segregated carbon atoms grew into nuclei for nanoscale carbides precipitation on subsequent tempering. |
| |
| Keywords: | Three-dimensional atom probe (3DAP) clusters grain boundary diffusion martensitic steels carbon segregation deep cryogenic treatment |
|
|
