Mechanism of Si on the Cementite Type Transformation in As-cast High Carbon Chromium Bearing Steel
Four as-cast high carbon chromium bearing steels with different Si contents （0. 29%、0. 42%、0. 71% and 1. 50%）were prepared using a vacuum induction furnace， the carbides in the steel were extracted by nonaqueous solution electrolysis method. The two-dimensional and three-dimensional morphology of ca...
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| Materialtyp: | Artikel |
| Språk: | zho |
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Editorial Office of Special Steel
2024-05-01
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| Serie: | Teshugang |
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| Länkar: | http://www.specialsteeljournal.com/fileup/1003-8620/PDF/2023-00201.pdf |
| Sammanfattning: | Four as-cast high carbon chromium bearing steels with different Si contents （0. 29%、0. 42%、0. 71% and
1. 50%）were prepared using a vacuum induction furnace， the carbides in the steel were extracted by nonaqueous solution
electrolysis method. The two-dimensional and three-dimensional morphology of carbides in steel was observed through
scanning electron microscopy. the types of carbides at different Si contents were investigated by X-ray diffractometer， the
essential mechanism of influence of Si content on cementite type was determined by thermodynamics and first principles
calculation. The research results indicate that there are two types of carbides in as-cast high carbon chromium bearing
steel with different Si contents， namely layer cementite （Fe1-XMnX ）3C and grain boundary carbides M23C6. With the in
crease of Si content （0. 29%-1. 50%）， the M23C6 grain boundary carbides change from a continuous coarse rod-shaped
structure to a discontinuous fine point like structure， which indicate that the increase of Si content has an inhibitory effect
on the precipitation of grain boundary carbides. In addition， the increase in Si content reduces the proportion of Mn in
（Fe1-XMnX ）3C cementite， and the transformation trend of cementite type is from Fe1. 8Mn1. 2C to Fe3Mn0C. The possible rea
son is that during the precipitation process of cementite formation， Si atoms are discharged into area around cementite to
form a Si rich micro zone， which hinders the diffusion of Mn atoms from the matrix to the cementite， reduces the activity
and diffusion migration ability of Mn in the matrix. Thus， the relative content of Mn in the cementite is reduced. |
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| ISSN: | 1003-8620 |