Abstract
The structural and phase transformations which take place in low-carbon 0.1% C-Mn-V-Ti steel during deformation by high pressure torsion (HPT) and subsequent heating have been studied using transmission electron microscopy and X-ray structural analysis methods. Whatever the initial state, be it ferritic-pearlitic or martensitic (obtained by quenching from 950°C and 1180°C), HPT at room temperature leads to the formation of a nanosized oriented grain-subgrain structure. The average size of the elements of the grain-subgrain structure in the 0.1% C-Mn-V-Ti steel after severe plastic deformation is larger in the initially ferritic-pearlitic state (95 nm) than in the initially martensitic states (65 and 50 nm after quenching from 950°C and 1180°C, respectively). It is shown that quenching from 950°C and 1180°C causes the formation of the martensite of different fineness, providing, in turn, nanostructures of different dimensions and different levels of the strength properties after HPT. Quenching from 1180°C is conducive to a higher thermal stability of the HPT-induced nanocrystalline structure of the 0.1% C-Mn-V-Ti steel on account of the larger amount of vanadium carbide precipitates. It is found that HPT leads to a considerable increase in the microhardness of the 0.1% C-Mn-V-Ti steel as compared to its microhardness in the initial state (more than 3 times as high in the ferritic-pearlitic state and more than 2 times as high the initially martensitic states).
Original language | English |
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Pages (from-to) | 109-120 |
Number of pages | 12 |
Journal | Nanotechnologies in Russia |
Volume | 4 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 1 Feb 2009 |
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Engineering(all)