The Effect of Coiling Temperature on the Microstructure and Mechanical Properties of a Niobium–Titanium Microalloyed Steel Processed via Thin Slab Casting
We describe here the influence of coiling temperature on the microstructure and mechanical properties, especially toughness, in a low carbon niobium microalloyed steel processed via thin slab casting. The objective is to elucidate the impact of coiling temperature on the nature and distribution of microstructural constituents (including different phases, precipitates, and dislocations) that contribute to variation in the strength–toughness relationship of these steels. In general, the microstructure primarily consisted of fine lath-type bainite and polygonal ferrite, and NbC, TiC and (Nb, Ti)C precipitates of size ~2–10 nm in the matrix and at dislocations. However, the dominance of bainite and distribution of precipitates was a function of coiling temperature. The lower coiling temperature provided superior strength–toughness combination and is attributed to predominantly bainitic microstructure and uniform precipitation of NbC, TiC, and (Nb, Ti)C during the coiling process, consistent with continuous cooling transformation diagrams.
V. S. Challa et al., "The Effect of Coiling Temperature on the Microstructure and Mechanical Properties of a Niobium–Titanium Microalloyed Steel Processed via Thin Slab Casting," Materials Science and Engineering A, vol. 595-153, Elsevier, Jan 2014.
The definitive version is available at http://dx.doi.org/10.1016/j.msea.2013.12.002
Materials Science and Engineering
Keywords and Phrases
Coiling temperature; Niobium-titanium microalloyed steel; Toughness; Precipitates; Dislocations
International Standard Serial Number (ISSN)
Article - Journal
© 2014 Elsevier