The Library
Elemental segregation and subsequent precipitation during solidification of continuous cast Nb–V–Ti high-strength low-alloy steels
Tools
Tools
Tools
Zheng, Shuguo, Davis, Claire and Strangwood, Martin (2014) Elemental segregation and subsequent precipitation during solidification of continuous cast Nb–V–Ti high-strength low-alloy steels. Materials Characterization, 95 . pp. 94-104. doi:10.1016/j.matchar.2014.06.008 ISSN 1044-5803.
Research output not available from this repository.
Request-a-Copy directly from author or use local Library Get it For Me service.
Official URL: http://dx.doi.org/10.1016/j.matchar.2014.06.008
Abstract
In this study, elemental segregation during solidification and subsequent precipitation behaviour in a continuous cast Nb–V–Ti high-strength low-alloy steel was investigated by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and thermodynamic modelling. It is known that for steels with low carbon contents the pearlite that forms on slow cooling does so where the interdendritic liquid was present prior to final solidification. The alloying elements of Nb, Ti, Mn and V segregate into the interdendritic liquid during solidification, while Al preferentially segregates into the solidifying solid phase. The composition analysis on the slab samples verified the predicted element segregation behaviour, with a smaller difference in the concentrations of Mn and V in the pearlite and dendritic ferrite regions being observed compared to the Nb levels. Small (30–100 nm) spherical or irregular shaped Nb-rich precipitates (Nb(C, N) and (Nb, V)(C, N)) were mainly found in the pearlite regions, while angular Al-rich (60–300 nm) precipitates were found in the dendritic ferrite regions, in the form of AlN and complex AlN–V(C, N) precipitates. Small isolated ferrite regions surrounded by pearlite were observed in the microstructure and has two origins: one type is dendritic ferrite that appears as an isolated island due to a sectioning effect when observing the two-dimensional microstructure; the other is a ferrite idiomorph that forms in the interdendritic region due to the low carbon content of the steel. Accordingly, in these isolated ferrite islands two different precipitation behaviours are found; predominantly Al-rich particles in the dendritic regions or predominantly Nb-rich precipitates in the interdendritic ferrite idiomorphs. No Al-rich precipitates were observed in the interdendritic regions (pearlite or isolated ferrite idiomorphs) despite the Thermo-Calc predictions indicating a higher volume fraction of AlN in these regions compared to the dendritic regions. This is believed to be due to back diffusion of nitrogen after solidification reducing the available nitrogen, which reacts with the high Nb levels present.
| Item Type: | Journal Article | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Divisions: | Faculty of Science, Engineering and Medicine > Engineering > WMG (Formerly the Warwick Manufacturing Group) | ||||||||||
| Journal or Publication Title: | Materials Characterization | ||||||||||
| Publisher: | Elsevier | ||||||||||
| ISSN: | 1044-5803 | ||||||||||
| Official Date: | September 2014 | ||||||||||
| Dates: |
|
||||||||||
| Volume: | 95 | ||||||||||
| Page Range: | pp. 94-104 | ||||||||||
| DOI: | 10.1016/j.matchar.2014.06.008 | ||||||||||
| Status: | Peer Reviewed | ||||||||||
| Publication Status: | Published | ||||||||||
| Access rights to Published version: | Restricted or Subscription Access |
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
