Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5455118 | Materials Science and Engineering: A | 2017 | 39 Pages |
Abstract
High silicon steels containing 1.5-2Â wt% silicon are considered to form carbide free bainite. However, the present work shows experimental evidence for the formation of nano-carbides in a series of medium carbon (0.61Â wt%) high silicon (1.71Â wt%) low alloy mixed phase steels with the help of transmission electron microscopy. The nano-carbide formation in bainite is attributed to the formation of inter-critical ferrite during continuous cooling, resulting in partitioning of carbon and silicon at the austenite-ferrite interface, leading to an increase in carbon and decrease in silicon at the austenite side of the interface. Due to diffusionless growth of supersaturated bainitic ferrite lath under para-equilibrium conditions, formation of bainite proceeds with higher carbon and lower silicon, allowing carbide formation in the bainite during subsequent holding at bainitic transformation temperature. Nano-carbides along with mixed phase microstructures are attributed to the excellent combination of high strength and high ductility in the present steels.
Keywords
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
A. Varshney, S. Sangal, Gouthama Gouthama, A.K. Pramanick, K. Mondal,