Precipitation behavior and austenite stability of Nb or Nb–Mo micro-alloyed warm-rolled medium-Mn steels

Journal article (2019)

Authors

Y. Ma Rheinisch-Westfälische Technische Hochschule
Affiliation
External organisation
More Info
expand_more

Published Date

2019-10

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Affiliation

External organisation

Abstract

Precipitation behavior and austenite stability of the warm-rolled medium-Mn steels with different Nb/Mo additions annealed at different temperatures were investigated. The Nb or Nb–Mo additions decrease the volume fraction of retained austenite, but increase its mechanical stability. The Mo addition to the Nb-bearing steels can lead to a higher density and smaller mean size of the precipitates because of the decreased interfacial energy and enhanced precipitation kinetics. The optimal precipitation temperature of the designed steels is about 600
°C. The Nb–Mo bearing steels exhibit a mixture of equiaxed and lamellar grain morphologies, and exceptional mechanical properties, i.e. the average products of ultimate tensile strength and total elongation (PSE) values of approx. 62 GPa %. An increase in yield strength of 300 MPa can result from grain refinement and precipitation hardening by Nb–Mo addition.